Bug 485559 – Boston Summit HarfBuzz optimizations

2007-10-10  Behdad Esfahbod  <behdad@gnome.org>

        Bug 485559 – Boston Summit HarfBuzz optimizations

        * pango/opentype/*: HarfBuzz hacking to:

          - Rename last remaining FT_Err stuff to HB_Err.

          - Fix a couple invalid table paths to be permissive so
            fonts work better.  Particularly GDEF table for Nafees
            Nastaliq is loaded and works great now.

          - Optimize harfbuzz buffer to not copy/swap for simple
          one-to-one and "copy" GSUB operations.

        * pango/pango-ot*: Update to FT_Err to HB_Err renaming.


svn path=/trunk/; revision=2431

22 files changed, 1264 insertions, 1318 deletions

diff --git a/pango/opentype/ftglue.c b/pango/opentype/ftglue.c
index 6444e67d..752c976f 100644
--- a/pango/opentype/ftglue.c
+++ b/pango/opentype/ftglue.c
@@ -32,16 +32,16 @@ _hb_ftglue_log( const char*   format, ... )
 static FT_Pointer
 _hb_ftglue_qalloc( FT_Memory  memory,
                FT_ULong   size,
-               FT_Error  *perror )
+               HB_Error  *perror )
 {
-  FT_Error    error = 0;
+  HB_Error    error = 0;
   FT_Pointer  block = NULL;
 
   if ( size > 0 )
   {
     block = memory->alloc( memory, size );
     if ( !block )
-      error = FT_Err_Out_Of_Memory;
+      error = HB_Err_Out_Of_Memory;
   }
 
   *perror = error;
@@ -55,16 +55,16 @@ _hb_ftglue_qalloc( FT_Memory  memory,
 FTGLUE_APIDEF( FT_Pointer )
 _hb_ftglue_alloc( FT_Memory  memory,
               FT_ULong   size,
-              FT_Error  *perror )
+              HB_Error  *perror )
 {
-  FT_Error    error = 0;
+  HB_Error    error = 0;
   FT_Pointer  block = NULL;
 
   if ( size > 0 )
   {
     block = memory->alloc( memory, size );
     if ( !block )
-      error = FT_Err_Out_Of_Memory;
+      error = HB_Err_Out_Of_Memory;
     else
       memset( (char*)block, 0, (size_t)size );
   }
@@ -79,10 +79,10 @@ _hb_ftglue_realloc( FT_Memory   memory,
                 FT_Pointer  block,
                 FT_ULong    old_size,
                 FT_ULong    new_size,
-                FT_Error   *perror )
+                HB_Error   *perror )
 {
   FT_Pointer  block2 = NULL;
-  FT_Error    error  = 0;
+  HB_Error    error  = 0;
 
   if ( old_size == 0 || block == NULL )
   {
@@ -96,7 +96,7 @@ _hb_ftglue_realloc( FT_Memory   memory,
   {
     block2 = memory->realloc( memory, old_size, new_size, block );
     if ( block2 == NULL )
-      error = FT_Err_Out_Of_Memory;
+      error = HB_Err_Out_Of_Memory;
     else if ( new_size > old_size )
       memset( (char*)block2 + old_size, 0, (size_t)(new_size - old_size) );
   }
@@ -126,31 +126,31 @@ _hb_ftglue_stream_pos( FT_Stream   stream )
 }
 
 
-FTGLUE_APIDEF( FT_Error )
+FTGLUE_APIDEF( HB_Error )
 _hb_ftglue_stream_seek( FT_Stream   stream,
                     FT_Long     pos )
 {
-  FT_Error  error = 0;
+  HB_Error  error = 0;
 
   stream->pos = pos;
   if ( stream->read )
   {
     if ( stream->read( stream, pos, NULL, 0 ) )
-      error = FT_Err_Invalid_Stream_Operation;
+      error = HB_Err_Invalid_Stream_Operation;
   }
   else if ( pos > (FT_Long)stream->size )
-    error = FT_Err_Invalid_Stream_Operation;
+    error = HB_Err_Invalid_Stream_Operation;
 
   LOG(( "ftglue:stream:seek(%ld) -> %d\n", pos, error ));
   return error;
 }
 
 
-FTGLUE_APIDEF( FT_Error )
+FTGLUE_APIDEF( HB_Error )
 _hb_ftglue_stream_frame_enter( FT_Stream   stream,
                            FT_ULong    count )
 {
-  FT_Error  error = FT_Err_Ok;
+  HB_Error  error = HB_Err_Ok;
   FT_ULong  read_bytes;
 
   if ( stream->read )
@@ -168,7 +168,7 @@ _hb_ftglue_stream_frame_enter( FT_Stream   stream,
     if ( read_bytes < count )
     {
       FREE( stream->base );
-      error = FT_Err_Invalid_Stream_Operation;
+      error = HB_Err_Invalid_Stream_Operation;
     }
     stream->cursor = stream->base;
     stream->limit  = stream->cursor + count;
@@ -180,7 +180,7 @@ _hb_ftglue_stream_frame_enter( FT_Stream   stream,
     if ( stream->pos >= stream->size        ||
          stream->pos + count > stream->size )
     {
-      error = FT_Err_Invalid_Stream_Operation;
+      error = HB_Err_Invalid_Stream_Operation;
       goto Exit;
     }
 
@@ -212,12 +212,12 @@ _hb_ftglue_stream_frame_exit( FT_Stream  stream )
 }
 
 
-FTGLUE_APIDEF( FT_Error )
+FTGLUE_APIDEF( HB_Error )
 _hb_ftglue_face_goto_table( FT_Face    face,
                         FT_ULong   the_tag,
                         FT_Stream  stream )
 {
-  FT_Error  error;
+  HB_Error  error;
 
   LOG(( "_hb_ftglue_face_goto_table( %p, %c%c%c%c, %p )\n",
                 face, 
@@ -230,7 +230,7 @@ _hb_ftglue_face_goto_table( FT_Face    face,
   if ( !FT_IS_SFNT(face) )
   {
     LOG(( "not a SFNT face !!\n" ));
-    error = FT_Err_Invalid_Face_Handle;
+    error = HB_Err_Invalid_Face_Handle;
   }
   else
   {
@@ -285,7 +285,7 @@ _hb_ftglue_face_goto_table( FT_Face    face,
         goto FoundIt;
       }
     }
-    error = FT_Err_Table_Missing;
+    error = HB_Err_Table_Missing;
 
   FoundIt:
     FORGET_Frame();
@@ -298,3 +298,12 @@ Exit:
 }                        
 
 #undef QALLOC
+
+/* abuse these private header/source files */
+
+/* helper func to set a breakpoint on */
+HB_Error
+_hb_err (HB_Error code)
+{
+  return code;
+}
diff --git a/pango/opentype/ftglue.h b/pango/opentype/ftglue.h
index 84de7f35..9b237dda 100644
--- a/pango/opentype/ftglue.h
+++ b/pango/opentype/ftglue.h
@@ -46,11 +46,17 @@
 #include <ft2build.h>
 #include FT_FREETYPE_H
 
+#include "harfbuzz-open.h"
+
 FT_BEGIN_HEADER
 
 
 /* utility macros */
 
+#ifndef HB_Error
+#define HB_Error FT_Error
+#endif
+
 #define  SET_ERR(c)   ( (error = (c)) != 0 )
 
 #ifndef FTGLUE_API
@@ -88,18 +94,18 @@ FT_BEGIN_HEADER
 FTGLUE_API( FT_Long )
 _hb_ftglue_stream_pos( FT_Stream   stream );
 
-FTGLUE_API( FT_Error )
+FTGLUE_API( HB_Error )
 _hb_ftglue_stream_seek( FT_Stream   stream,
                     FT_Long     pos );
 
-FTGLUE_API( FT_Error )
+FTGLUE_API( HB_Error )
 _hb_ftglue_stream_frame_enter( FT_Stream   stream,
                            FT_ULong    size );
 
 FTGLUE_API( void )
 _hb_ftglue_stream_frame_exit( FT_Stream  stream );
 
-FTGLUE_API( FT_Error )
+FTGLUE_API( HB_Error )
 _hb_ftglue_face_goto_table( FT_Face    face,
                         FT_ULong   tag,
                         FT_Stream  stream );
@@ -132,19 +138,24 @@ _hb_ftglue_face_goto_table( FT_Face    face,
 FTGLUE_API( FT_Pointer )
 _hb_ftglue_alloc( FT_Memory  memory,
               FT_ULong   size,
-              FT_Error  *perror_ );
+              HB_Error  *perror_ );
 
 FTGLUE_API( FT_Pointer )
 _hb_ftglue_realloc( FT_Memory   memory,
                 FT_Pointer  block,
                 FT_ULong    old_size,
                 FT_ULong    new_size,
-                FT_Error   *perror_ );
+                HB_Error   *perror_ );
 
 FTGLUE_API( void )
 _hb_ftglue_free( FT_Memory   memory,
              FT_Pointer  block );
 
+/* abuse these private header/source files */
+
+/* helper func to set a breakpoint on */
+HB_Error _hb_err (HB_Error code);
+
 FT_END_HEADER
 
 #endif /* FTGLUE_H */
diff --git a/pango/opentype/harfbuzz-buffer.c b/pango/opentype/harfbuzz-buffer.c
index 40a7d2b8..148d98d9 100644
--- a/pango/opentype/harfbuzz-buffer.c
+++ b/pango/opentype/harfbuzz-buffer.c
@@ -1,6 +1,6 @@
 /* harfbuzz-buffer.c: Buffer of glyphs for substitution/positioning
  *
- * Copyright 2004 Red Hat Software
+ * Copyright 2004,2007 Red Hat Software
  *
  * Portions Copyright 1996-2000 by
  * David Turner, Robert Wilhelm, and Werner Lemberg.
@@ -11,7 +11,34 @@
 #include "harfbuzz-gsub-private.h"
 #include "harfbuzz-gpos-private.h"
 
-static FT_Error
+/* Here is how the buffer works internally:
+ *
+ * There are two string pointers: in_string and out_string.  They
+ * always have same allocated size, but different length and positions.
+ *
+ * As an optimization, both in_string and out_string may point to the
+ * same piece of memory, which is owned by in_string.  This remains the
+ * case as long as:
+ *
+ *   - copy_glyph() is called
+ *   - replace_glyph() is called with inplace=TRUE
+ *   - add_output_glyph() and add_output_glyphs() are not called
+ *
+ * In that case swap(), and copy_glyph(), and replace_glyph() are all
+ * mostly no-op.
+ *
+ * As soon an add_output_glyph[s]() or replace_glyph() with inplace=FALSE is
+ * called, out_string is moved over to an alternate buffer (alt_string), and
+ * its current contents (out_length entries) are copied to the alt buffer.
+ * This should all remain transparent to the user.  swap() then switches
+ * in_string and alt_string.  alt_string is not allocated until its needed,
+ * but after that it's grown with in_string unconditionally.
+ *
+ * The buffer->inplace boolean keeps status of whether out_string points to
+ * in_string or alt_string.
+ */
+
+static HB_Error
 hb_buffer_ensure( HB_Buffer buffer,
 		   FT_ULong   size )
 {
@@ -20,29 +47,63 @@ hb_buffer_ensure( HB_Buffer buffer,
 
   if (size > new_allocated)
     {
-      FT_Error error;
+      HB_Error error;
 
       while (size > new_allocated)
 	new_allocated += (new_allocated >> 1) + 8;
       
-      if ( REALLOC_ARRAY( buffer->in_string, buffer->allocated, new_allocated, HB_GlyphItemRec ) )
-	return error;
-      if ( REALLOC_ARRAY( buffer->out_string, buffer->allocated, new_allocated, HB_GlyphItemRec ) )
-	return error;
       if ( REALLOC_ARRAY( buffer->positions, buffer->allocated, new_allocated, HB_PositionRec ) )
 	return error;
+      if ( REALLOC_ARRAY( buffer->in_string, buffer->allocated, new_allocated, HB_GlyphItemRec ) )
+	return error;
+      if ( buffer->inplace )
+        {
+	  buffer->out_string = buffer->in_string;
+
+	  if ( buffer->alt_string )
+	    {
+	      if ( REALLOC_ARRAY( buffer->alt_string, buffer->allocated, new_allocated, HB_GlyphItemRec ) )
+		return error;
+	    }
+	}
+      else
+        {
+	  if ( REALLOC_ARRAY( buffer->alt_string, buffer->allocated, new_allocated, HB_GlyphItemRec ) )
+	    return error;
+
+	  buffer->out_string = buffer->alt_string;
+	}
 
       buffer->allocated = new_allocated;
     }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
-FT_Error
+static HB_Error
+hb_buffer_duplicate_out_buffer( HB_Buffer buffer )
+{
+  if ( !buffer->alt_string )
+    {
+      FT_Memory memory = buffer->memory;
+      HB_Error error;
+
+      if ( ALLOC_ARRAY( buffer->alt_string, buffer->allocated, HB_GlyphItemRec ) )
+	return error;
+    }
+
+  buffer->out_string = buffer->alt_string;
+  memcpy( buffer->out_string, buffer->in_string, buffer->out_length * sizeof (buffer->out_string[0]) );
+  buffer->inplace = FALSE;
+
+  return HB_Err_Ok;
+}
+
+HB_Error
 hb_buffer_new( FT_Memory   memory,
 		HB_Buffer *buffer )
 {
-  FT_Error error;
+  HB_Error error;
   
   if ( ALLOC( *buffer, sizeof( HB_BufferRec ) ) )
     return error;
@@ -56,61 +117,77 @@ hb_buffer_new( FT_Memory   memory,
 
   (*buffer)->in_string = NULL;
   (*buffer)->out_string = NULL;
+  (*buffer)->alt_string = NULL;
   (*buffer)->positions = NULL;
   (*buffer)->max_ligID = 0;
+  (*buffer)->inplace = TRUE;
+
+  return HB_Err_Ok;
+}
 
-  return FT_Err_Ok;
+void
+hb_buffer_clear_output( HB_Buffer buffer )
+{
+  buffer->out_length = 0;
+  buffer->out_pos = 0;
+  buffer->out_string = buffer->in_string;
+  buffer->inplace = TRUE;
 }
 
-FT_Error
+void
 hb_buffer_swap( HB_Buffer buffer )
 {
   HB_GlyphItem tmp_string;
+  int tmp_length;
+  int tmp_pos;
 
-  tmp_string = buffer->in_string;
-  buffer->in_string = buffer->out_string;
-  buffer->out_string = tmp_string;
+  if ( ! buffer->inplace )
+    {
+      tmp_string = buffer->in_string;
+      buffer->in_string = buffer->out_string;
+      buffer->out_string = tmp_string;
+      buffer->alt_string = buffer->out_string;
+    }
 
+  tmp_length = buffer->in_length;
   buffer->in_length = buffer->out_length;
-  buffer->out_length = 0;
-  
-  buffer->in_pos = 0;
-  buffer->out_pos = 0;
+  buffer->out_length = tmp_length;
 
-  return FT_Err_Ok;
+  tmp_pos = buffer->in_pos;
+  buffer->in_pos = buffer->out_pos;
+  buffer->out_pos = tmp_pos;
 }
 
-FT_Error
+void
 hb_buffer_free( HB_Buffer buffer )
 {
   FT_Memory memory = buffer->memory;
 
   FREE( buffer->in_string );
-  FREE( buffer->out_string );
+  FREE( buffer->alt_string );
+  buffer->out_string = NULL;
   FREE( buffer->positions );
   FREE( buffer );
-
-  return FT_Err_Ok;
 }
 
-FT_Error
+void
 hb_buffer_clear( HB_Buffer buffer )
 {
   buffer->in_length = 0;
   buffer->out_length = 0;
   buffer->in_pos = 0;
   buffer->out_pos = 0;
-  
-  return FT_Err_Ok;
+  buffer->out_string = buffer->in_string;
+  buffer->inplace = TRUE;
 }
 
-FT_Error
+HB_Error
 hb_buffer_add_glyph( HB_Buffer buffer,
 		      FT_UInt    glyph_index,
 		      FT_UInt    properties,
 		      FT_UInt    cluster )
 {
-  FT_Error error;
+  HB_Error error;
   HB_GlyphItem glyph;
   
   error = hb_buffer_ensure( buffer, buffer->in_length + 1 );
@@ -127,7 +204,7 @@ hb_buffer_add_glyph( HB_Buffer buffer,
   
   buffer->in_length++;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 /* The following function copies `num_out' elements from `glyph_data'
@@ -149,7 +226,7 @@ hb_buffer_add_glyph( HB_Buffer buffer,
 
    The cluster value for the glyph at position buffer->in_pos is used
    for all replacement glyphs */
-FT_Error
+HB_Error
 hb_buffer_add_output_glyphs( HB_Buffer buffer,
 			      FT_UShort  num_in,
 			      FT_UShort  num_out,
@@ -157,7 +234,7 @@ hb_buffer_add_output_glyphs( HB_Buffer buffer,
 			      FT_UShort  component,
 			      FT_UShort  ligID )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_UShort i;
   FT_UInt properties;
   FT_UInt cluster;
@@ -166,6 +243,13 @@ hb_buffer_add_output_glyphs( HB_Buffer buffer,
   if ( error )
     return error;
 
+  if ( buffer->inplace )
+    {
+      error = hb_buffer_duplicate_out_buffer( buffer );
+      if ( error )
+	return error;
+    }
+
   properties = buffer->in_string[buffer->in_pos].properties;
   cluster = buffer->in_string[buffer->in_pos].cluster;
   if ( component == 0xFFFF )
@@ -190,10 +274,10 @@ hb_buffer_add_output_glyphs( HB_Buffer buffer,
 
   buffer->out_length = buffer->out_pos;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
-FT_Error
+HB_Error
 hb_buffer_add_output_glyph( HB_Buffer buffer,	
 			     FT_UInt    glyph_index,
 			     FT_UShort  component,
@@ -205,19 +289,49 @@ hb_buffer_add_output_glyph( HB_Buffer buffer,
 					&glyph_data, component, ligID );
 }
 
-FT_Error
+HB_Error
 hb_buffer_copy_output_glyph ( HB_Buffer buffer )
 {  
-  FT_Error  error;
+  HB_Error  error;
 
   error = hb_buffer_ensure( buffer, buffer->out_pos + 1 );
   if ( error )
     return error;
   
-  buffer->out_string[buffer->out_pos++] = buffer->in_string[buffer->in_pos++];
+  if ( ! buffer->inplace )
+    {
+      buffer->out_string[buffer->out_pos] = buffer->in_string[buffer->in_pos];
+    }
+
+  buffer->in_pos++;
+  buffer->out_pos++;
   buffer->out_length = buffer->out_pos;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
+}
+
+HB_Error
+hb_buffer_replace_output_glyph( HB_Buffer buffer,	
+				FT_UInt   glyph_index,
+				FT_Bool   inplace )
+{
+
+  HB_Error error;
+
+  if ( inplace )
+    {
+      error = hb_buffer_copy_output_glyph ( buffer );
+      if ( error )
+	return error;
+
+      buffer->out_string[buffer->out_pos-1].gindex = glyph_index;
+    }
+  else
+    {
+      return hb_buffer_add_output_glyph( buffer, glyph_index, 0xFFFF, 0xFFFF );
+    }
+
+  return HB_Err_Ok;
 }
 
 FT_UShort
diff --git a/pango/opentype/harfbuzz-buffer.h b/pango/opentype/harfbuzz-buffer.h
index c7478e38..8b6b659f 100644
--- a/pango/opentype/harfbuzz-buffer.h
+++ b/pango/opentype/harfbuzz-buffer.h
@@ -56,32 +56,37 @@ typedef struct HB_BufferRec_{
   FT_ULong    in_pos;
   FT_ULong    out_pos;
   
+  FT_Bool       inplace;
   HB_GlyphItem  in_string;
   HB_GlyphItem  out_string;
+  HB_GlyphItem  alt_string;
   HB_Position   positions;
   FT_UShort      max_ligID;
 } HB_BufferRec, *HB_Buffer;
 
-FT_Error
+HB_Error
 hb_buffer_new( FT_Memory   memory,
 		HB_Buffer *buffer );
 
-FT_Error
+void
 hb_buffer_swap( HB_Buffer buffer );
 
-FT_Error
+void
 hb_buffer_free( HB_Buffer buffer );
 
-FT_Error
+void
 hb_buffer_clear( HB_Buffer buffer );
 
-FT_Error
+void
+hb_buffer_clear_output( HB_Buffer buffer );
+
+HB_Error
 hb_buffer_add_glyph( HB_Buffer buffer,
 		      FT_UInt    glyph_index,
 		      FT_UInt    properties,
 		      FT_UInt    cluster );
 
-FT_Error
+HB_Error
 hb_buffer_add_output_glyphs( HB_Buffer buffer,
 			      FT_UShort  num_in,
 			      FT_UShort  num_out,
@@ -89,15 +94,20 @@ hb_buffer_add_output_glyphs( HB_Buffer buffer,
 			      FT_UShort  component,
 			      FT_UShort  ligID );
 
-FT_Error
+HB_Error
 hb_buffer_add_output_glyph ( HB_Buffer buffer,
 			      FT_UInt    glyph_index,
 			      FT_UShort  component,
 			      FT_UShort  ligID );
 
-FT_Error
+HB_Error
 hb_buffer_copy_output_glyph ( HB_Buffer buffer );
 
+HB_Error
+hb_buffer_replace_output_glyph ( HB_Buffer buffer,
+				 FT_UInt   glyph_index,
+				 FT_Bool   inplace );
+
 FT_UShort
 hb_buffer_allocate_ligid( HB_Buffer buffer );
 
diff --git a/pango/opentype/harfbuzz-dump-main.c b/pango/opentype/harfbuzz-dump-main.c
index 81fecf43..4a95f2e5 100644
--- a/pango/opentype/harfbuzz-dump-main.c
+++ b/pango/opentype/harfbuzz-dump-main.c
@@ -28,7 +28,7 @@
 #define N_ELEMENTS(arr) (sizeof(arr)/ sizeof((arr)[0]))
 
 static int
-croak (const char *situation, FT_Error error)
+croak (const char *situation, HB_Error error)
 {
   fprintf (stderr, "%s: Error %d\n", situation, error);
 
@@ -59,7 +59,7 @@ maybe_add_feature (HB_GSUB  gsub,
 		   FT_ULong  tag,
 		   FT_UShort property)
 {
-  FT_Error error;
+  HB_Error error;
   FT_UShort feature_index;
   
   /* 0xffff == default language system */
@@ -122,7 +122,7 @@ select_cmap (FT_Face face)
 static void
 add_features (HB_GSUB gsub)
 {
-  FT_Error error;
+  HB_Error error;
   FT_ULong tag = FT_MAKE_TAG ('a', 'r', 'a', 'b');
   FT_UShort script_index;
 
@@ -173,7 +173,7 @@ try_string (FT_Library library,
 	    FT_Face    face,
 	    HB_GSUB   gsub)
 {
-  FT_Error error;
+  HB_Error error;
   HB_GSUB_String *in_str;
   HB_GSUB_String *out_str;
   FT_ULong i;
@@ -210,7 +210,7 @@ try_string (FT_Library library,
 int 
 main (int argc, char **argv)
 {
-  FT_Error error;
+  HB_Error error;
   FT_Library library;
   FT_Face face;
   HB_GSUB gsub;
@@ -238,7 +238,7 @@ main (int argc, char **argv)
       if ((error = HB_Done_GSUB_Table (gsub)))
 	croak ("HB_Done_GSUB_Table", error);
     }
-  else if (error != FT_Err_Table_Missing)
+  else if (error != HB_Err_Table_Missing)
     fprintf (stderr, "HB_Load_GSUB_Table %x\n", error);
 
   if (!(error = HB_Load_GPOS_Table (face, &gpos, NULL)))
@@ -248,7 +248,7 @@ main (int argc, char **argv)
       if ((error = HB_Done_GPOS_Table (gpos)))
 	croak ("HB_Done_GPOS_Table", error);
     }
-  else if (error != FT_Err_Table_Missing)
+  else if (error != HB_Err_Table_Missing)
     fprintf (stderr, "HB_Load_GPOS_Table %x\n", error);
 
   printf ("</OpenType>\n");
diff --git a/pango/opentype/harfbuzz-dump.c b/pango/opentype/harfbuzz-dump.c
index bf30f66b..53feba12 100644
--- a/pango/opentype/harfbuzz-dump.c
+++ b/pango/opentype/harfbuzz-dump.c
@@ -452,7 +452,7 @@ static void
 Dump_Device (HB_Device *Device, FILE *stream, int indent, HB_Type hb_type)
 {
   int i;
-  int bits = 0;
+  int bits;
   int n_per;
   unsigned int mask;
 
@@ -472,6 +472,9 @@ Dump_Device (HB_Device *Device, FILE *stream, int indent, HB_Type hb_type)
     case 3:
       bits = 8;
       break;
+    default:
+      bits = 0;
+      break;
     }
 
   DUMP ("<DeltaValue>");
@@ -634,7 +637,7 @@ Dump_GPOS_Lookup_Markbase (HB_SubTable *subtable, FILE *stream, int indent, HB_T
 DEF_DUMP (Lookup)
 {
   int i;
-  const char *lookup_name = NULL;
+  const char *lookup_name;
   void (*lookup_func) (HB_SubTable *subtable, FILE *stream, int indent, HB_Type hb_type) = NULL;
 
   if (hb_type == HB_Type_GSUB)
@@ -663,6 +666,10 @@ DEF_DUMP (Lookup)
 	  lookup_name = "CHAIN";
 	  lookup_func = Dump_GSUB_Lookup_Chain;
 	  break;
+	default:
+	  lookup_name = "(unknown)";
+	  lookup_func = NULL;
+	  break;
 	}
     }
   else
@@ -696,6 +703,10 @@ DEF_DUMP (Lookup)
 	case HB_GPOS_LOOKUP_CHAIN:
 	  lookup_name = "CHAIN";
 	  break;
+	default:
+	  lookup_name = "(unknown)";
+	  lookup_func = NULL;
+	  break;
 	}
     }
 
diff --git a/pango/opentype/harfbuzz-gdef-private.h b/pango/opentype/harfbuzz-gdef-private.h
index e07e2364..e93fd44e 100644
--- a/pango/opentype/harfbuzz-gdef-private.h
+++ b/pango/opentype/harfbuzz-gdef-private.h
@@ -87,11 +87,11 @@ struct  HB_LigGlyph_
 };
 
 
-FT_Error  _HB_GDEF_Add_Glyph_Property( HB_GDEFHeader*   gdef,
+HB_Error  _HB_GDEF_Add_Glyph_Property( HB_GDEFHeader*   gdef,
 				       FT_UShort        glyphID,
 				       FT_UShort        property );
 
-FT_Error  _HB_GDEF_Check_Property( HB_GDEFHeader*   gdef,
+HB_Error  _HB_GDEF_Check_Property( HB_GDEFHeader*   gdef,
 				   HB_GlyphItem    item,
 				   FT_UShort        flags,
 				   FT_UShort*       property );
diff --git a/pango/opentype/harfbuzz-gdef.c b/pango/opentype/harfbuzz-gdef.c
index 7a30d8bd..859c81bb 100644
--- a/pango/opentype/harfbuzz-gdef.c
+++ b/pango/opentype/harfbuzz-gdef.c
@@ -14,9 +14,9 @@
 #include "harfbuzz-gdef-private.h"
 #include "harfbuzz-open-private.h"
 
-static FT_Error  Load_AttachList( HB_AttachList*  al,
+static HB_Error  Load_AttachList( HB_AttachList*  al,
 				  FT_Stream        stream );
-static FT_Error  Load_LigCaretList( HB_LigCaretList*  lcl,
+static HB_Error  Load_LigCaretList( HB_LigCaretList*  lcl,
 				    FT_Stream          stream );
 
 static void  Free_AttachList( HB_AttachList*  al,
@@ -37,7 +37,7 @@ static void  Free_NewGlyphClasses( HB_GDEFHeader*  gdef,
 #define GDEF_ID  Build_Extension_ID( 'G', 'D', 'E', 'F' )
 
 
-static FT_Error  GDEF_Create( void*  ext,
+static HB_Error  GDEF_Create( void*  ext,
 			      PFace  face )
 {
   DEFINE_LOAD_LOCALS( face->stream );
@@ -49,7 +49,7 @@ static FT_Error  GDEF_Create( void*  ext,
   /* by convention */
 
   if ( !gdef )
-    return FT_Err_Ok;
+    return HB_Err_Ok;
 
   /* a null offset indicates that there is no GDEF table */
 
@@ -59,7 +59,7 @@ static FT_Error  GDEF_Create( void*  ext,
 
   table = HB_LookUp_Table( face, TTAG_GDEF );
   if ( table < 0 )
-    return FT_Err_Ok;             /* The table is optional */
+    return HB_Err_Ok;             /* The table is optional */
 
   if ( FILE_Seek( face->dirTables[table].Offset ) ||
        ACCESS_Frame( 4L ) )
@@ -72,11 +72,11 @@ static FT_Error  GDEF_Create( void*  ext,
 
   gdef->loaded = FALSE;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
-static FT_Error  GDEF_Destroy( void*  ext,
+static HB_Error  GDEF_Destroy( void*  ext,
 			       PFace  face )
 {
   HB_GDEFHeader*  gdef = (HB_GDEFHeader*)ext;
@@ -85,7 +85,7 @@ static FT_Error  GDEF_Destroy( void*  ext,
   /* by convention */
 
   if ( !gdef )
-    return FT_Err_Ok;
+    return HB_Err_Ok;
 
   if ( gdef->loaded )
   {
@@ -97,18 +97,18 @@ static FT_Error  GDEF_Destroy( void*  ext,
     Free_NewGlyphClasses( gdef, memory );
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
 
-FT_Error  HB_Init_GDEF_Extension( HB_Engine  engine )
+HB_Error  HB_Init_GDEF_Extension( HB_Engine  engine )
 {
   PEngine_Instance  _engine = HANDLE_Engine( engine );
 
 
   if ( !_engine )
-    return FT_Err_Invalid_Engine;
+    return HB_Err_Invalid_Engine;
 
   return  HB_Register_Extension( _engine,
 				 GDEF_ID,
@@ -130,16 +130,16 @@ FT_Error  HB_Init_GDEF_Extension( HB_Engine  engine )
 
 
 
-FT_Error  HB_New_GDEF_Table( FT_Face          face,
+HB_Error  HB_New_GDEF_Table( FT_Face          face,
 			     HB_GDEFHeader** retptr )
 {
-  FT_Error         error;
+  HB_Error         error;
   FT_Memory        memory = face->memory;
 
   HB_GDEFHeader*  gdef;
 
   if ( !retptr )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   if ( ALLOC( gdef, sizeof( *gdef ) ) )
     return error;
@@ -157,14 +157,14 @@ FT_Error  HB_New_GDEF_Table( FT_Face          face,
 
   *retptr = gdef;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
-FT_Error  HB_Load_GDEF_Table( FT_Face          face,
+HB_Error  HB_Load_GDEF_Table( FT_Face          face,
 			      HB_GDEFHeader** retptr )
 {
-  FT_Error         error;
+  HB_Error         error;
   FT_Memory        memory = face->memory;
   FT_Stream        stream = face->stream;
   FT_ULong         cur_offset, new_offset, base_offset;
@@ -173,7 +173,7 @@ FT_Error  HB_Load_GDEF_Table( FT_Face          face,
 
 
   if ( !retptr )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   if (( error = _hb_ftglue_face_goto_table( face, TTAG_GDEF, stream ) ))
     return error;
@@ -204,7 +204,7 @@ FT_Error  HB_Load_GDEF_Table( FT_Face          face,
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
 	 ( error = _HB_OPEN_Load_ClassDefinition( &gdef->GlyphClassDef, 5,
-					 stream ) ) != FT_Err_Ok )
+					 stream ) ) != HB_Err_Ok )
       goto Fail0;
     (void)FILE_Seek( cur_offset );
   }
@@ -223,7 +223,7 @@ FT_Error  HB_Load_GDEF_Table( FT_Face          face,
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
 	 ( error = Load_AttachList( &gdef->AttachList,
-				    stream ) ) != FT_Err_Ok )
+				    stream ) ) != HB_Err_Ok )
       goto Fail1;
     (void)FILE_Seek( cur_offset );
   }
@@ -242,7 +242,7 @@ FT_Error  HB_Load_GDEF_Table( FT_Face          face,
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
 	 ( error = Load_LigCaretList( &gdef->LigCaretList,
-				      stream ) ) != FT_Err_Ok )
+				      stream ) ) != HB_Err_Ok )
       goto Fail2;
     (void)FILE_Seek( cur_offset );
   }
@@ -265,7 +265,7 @@ FT_Error  HB_Load_GDEF_Table( FT_Face          face,
 
   *retptr = gdef;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail3:
   Free_LigCaretList( &gdef->LigCaretList, memory );
@@ -283,7 +283,7 @@ Fail0:
 }
 
 
-FT_Error  HB_Done_GDEF_Table ( HB_GDEFHeader* gdef ) 
+HB_Error  HB_Done_GDEF_Table ( HB_GDEFHeader* gdef ) 
 {
   FT_Memory memory = gdef->memory;
   
@@ -296,7 +296,7 @@ FT_Error  HB_Done_GDEF_Table ( HB_GDEFHeader* gdef )
 
   FREE( gdef );
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
@@ -309,11 +309,11 @@ FT_Error  HB_Done_GDEF_Table ( HB_GDEFHeader* gdef )
 
 /* AttachPoint */
 
-static FT_Error  Load_AttachPoint( HB_AttachPoint*  ap,
+static HB_Error  Load_AttachPoint( HB_AttachPoint*  ap,
 				   FT_Stream         stream )
 {
   FT_Memory memory = stream->memory;
-  FT_Error  error;
+  HB_Error  error;
 
   FT_UShort   n, count;
   FT_UShort*  pi;
@@ -347,7 +347,7 @@ static FT_Error  Load_AttachPoint( HB_AttachPoint*  ap,
     FORGET_Frame();
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
@@ -360,11 +360,11 @@ static void  Free_AttachPoint( HB_AttachPoint*  ap,
 
 /* AttachList */
 
-static FT_Error  Load_AttachList( HB_AttachList*  al,
+static HB_Error  Load_AttachList( HB_AttachList*  al,
 				  FT_Stream        stream )
 {
   FT_Memory memory = stream->memory;
-  FT_Error  error;
+  HB_Error  error;
 
   FT_UShort         n, m, count;
   FT_ULong          cur_offset, new_offset, base_offset;
@@ -383,7 +383,7 @@ static FT_Error  Load_AttachList( HB_AttachList*  al,
 
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
-       ( error = _HB_OPEN_Load_Coverage( &al->Coverage, stream ) ) != FT_Err_Ok )
+       ( error = _HB_OPEN_Load_Coverage( &al->Coverage, stream ) ) != HB_Err_Ok )
     return error;
   (void)FILE_Seek( cur_offset );
 
@@ -412,14 +412,14 @@ static FT_Error  Load_AttachList( HB_AttachList*  al,
 
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
-	 ( error = Load_AttachPoint( &ap[n], stream ) ) != FT_Err_Ok )
+	 ( error = Load_AttachPoint( &ap[n], stream ) ) != HB_Err_Ok )
       goto Fail1;
     (void)FILE_Seek( cur_offset );
   }
 
   al->loaded = TRUE;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   for ( m = 0; m < n; m++ )
@@ -470,10 +470,10 @@ static void  Free_AttachList( HB_AttachList*  al,
 /* CaretValueFormat3 */
 /* CaretValueFormat4 */
 
-static FT_Error  Load_CaretValue( HB_CaretValue*  cv,
+static HB_Error  Load_CaretValue( HB_CaretValue*  cv,
 				  FT_Stream        stream )
 {
-  FT_Error  error;
+  HB_Error  error;
 
   FT_ULong cur_offset, new_offset, base_offset;
 
@@ -522,7 +522,7 @@ static FT_Error  Load_CaretValue( HB_CaretValue*  cv,
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
 	 ( error = _HB_OPEN_Load_Device( &cv->cvf.cvf3.Device,
-				stream ) ) != FT_Err_Ok )
+				stream ) ) != HB_Err_Ok )
       return error;
     (void)FILE_Seek( cur_offset );
 
@@ -538,10 +538,10 @@ static FT_Error  Load_CaretValue( HB_CaretValue*  cv,
     break;
 
   default:
-    return HB_Err_Invalid_GDEF_SubTable_Format;
+    return _hb_err(HB_Err_Invalid_GDEF_SubTable_Format);
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
@@ -555,11 +555,11 @@ static void  Free_CaretValue( HB_CaretValue*  cv,
 
 /* LigGlyph */
 
-static FT_Error  Load_LigGlyph( HB_LigGlyph*  lg,
+static HB_Error  Load_LigGlyph( HB_LigGlyph*  lg,
 				FT_Stream      stream )
 {
   FT_Memory memory = stream->memory;
-  FT_Error  error;
+  HB_Error  error;
 
   FT_UShort        n, m, count;
   FT_ULong         cur_offset, new_offset, base_offset;
@@ -594,12 +594,12 @@ static FT_Error  Load_LigGlyph( HB_LigGlyph*  lg,
 
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
-	 ( error = Load_CaretValue( &cv[n], stream ) ) != FT_Err_Ok )
+	 ( error = Load_CaretValue( &cv[n], stream ) ) != HB_Err_Ok )
       goto Fail;
     (void)FILE_Seek( cur_offset );
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail:
   for ( m = 0; m < n; m++ )
@@ -633,11 +633,11 @@ static void  Free_LigGlyph( HB_LigGlyph*  lg,
 
 /* LigCaretList */
 
-static FT_Error  Load_LigCaretList( HB_LigCaretList*  lcl,
+static HB_Error  Load_LigCaretList( HB_LigCaretList*  lcl,
 				    FT_Stream          stream )
 {
   FT_Memory memory = stream->memory;
-  FT_Error  error;
+  HB_Error  error;
 
   FT_UShort      m, n, count;
   FT_ULong       cur_offset, new_offset, base_offset;
@@ -656,7 +656,7 @@ static FT_Error  Load_LigCaretList( HB_LigCaretList*  lcl,
 
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
-       ( error = _HB_OPEN_Load_Coverage( &lcl->Coverage, stream ) ) != FT_Err_Ok )
+       ( error = _HB_OPEN_Load_Coverage( &lcl->Coverage, stream ) ) != HB_Err_Ok )
     return error;
   (void)FILE_Seek( cur_offset );
 
@@ -685,14 +685,14 @@ static FT_Error  Load_LigCaretList( HB_LigCaretList*  lcl,
 
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
-	 ( error = Load_LigGlyph( &lg[n], stream ) ) != FT_Err_Ok )
+	 ( error = Load_LigGlyph( &lg[n], stream ) ) != HB_Err_Ok )
       goto Fail1;
     (void)FILE_Seek( cur_offset );
   }
 
   lcl->loaded = TRUE;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   for ( m = 0; m < n; m++ )
@@ -778,17 +778,17 @@ static FT_UShort  Get_New_Class( HB_GDEFHeader*  gdef,
 
 
 
-FT_Error  HB_GDEF_Get_Glyph_Property( HB_GDEFHeader*  gdef,
+HB_Error  HB_GDEF_Get_Glyph_Property( HB_GDEFHeader*  gdef,
 				      FT_UShort        glyphID,
 				      FT_UShort*       property )
 {
   FT_UShort class, index;
 
-  FT_Error  error;
+  HB_Error  error;
 
 
   if ( !gdef || !property )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   /* first, we check for mark attach classes */
 
@@ -800,7 +800,7 @@ FT_Error  HB_GDEF_Get_Glyph_Property( HB_GDEFHeader*  gdef,
     if ( !error )
     {
       *property = class << 8;
-      return FT_Err_Ok;
+      return HB_Err_Ok;
     }
   }
 
@@ -816,6 +816,7 @@ FT_Error  HB_GDEF_Get_Glyph_Property( HB_GDEFHeader*  gdef,
 
   switch ( class )
   {
+  default:
   case UNCLASSIFIED_GLYPH:
     *property = 0;
     break;
@@ -837,17 +838,17 @@ FT_Error  HB_GDEF_Get_Glyph_Property( HB_GDEFHeader*  gdef,
     break;
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
-static FT_Error  Make_ClassRange( HB_ClassDefinition*  cd,
+static HB_Error  Make_ClassRange( HB_ClassDefinition*  cd,
 				  FT_UShort             start,
 				  FT_UShort             end,
 				  FT_UShort             class,
 				  FT_Memory             memory )
 {
-  FT_Error               error;
+  HB_Error               error;
   FT_UShort              index;
 
   HB_ClassDefFormat2*   cdf2;
@@ -873,12 +874,12 @@ static FT_Error  Make_ClassRange( HB_ClassDefinition*  cd,
 
   cd->Defined[class] = TRUE;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
 
-FT_Error  HB_GDEF_Build_ClassDefinition( HB_GDEFHeader*  gdef,
+HB_Error  HB_GDEF_Build_ClassDefinition( HB_GDEFHeader*  gdef,
 					 FT_UShort        num_glyphs,
 					 FT_UShort        glyph_count,
 					 FT_UShort*       glyph_array,
@@ -886,7 +887,7 @@ FT_Error  HB_GDEF_Build_ClassDefinition( HB_GDEFHeader*  gdef,
 {
   FT_UShort              start, curr_glyph, curr_class;
   FT_UShort              n, m, count;
-  FT_Error               error;
+  HB_Error               error;
   FT_Memory              memory;
 
   HB_ClassDefinition*   gcd;
@@ -895,7 +896,7 @@ FT_Error  HB_GDEF_Build_ClassDefinition( HB_GDEFHeader*  gdef,
 
 
   if ( !gdef || !glyph_array || !class_array )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   memory = gdef->memory;
   gcd = &gdef->GlyphClassDef;
@@ -918,13 +919,13 @@ FT_Error  HB_GDEF_Build_ClassDefinition( HB_GDEFHeader*  gdef,
 
   if ( curr_class >= 5 )
   {
-    error = FT_Err_Invalid_Argument;
+    error = HB_Err_Invalid_Argument;
     goto Fail4;
   }
 
   glyph_count--;
 
-  for ( n = 0; n <= glyph_count; n++ )
+  for ( n = 0; n < glyph_count + 1; n++ )
   {
     if ( curr_glyph == glyph_array[n] && curr_class == class_array[n] )
     {
@@ -933,14 +934,14 @@ FT_Error  HB_GDEF_Build_ClassDefinition( HB_GDEFHeader*  gdef,
 	if ( ( error = Make_ClassRange( gcd, start,
 					curr_glyph,
 					curr_class,
-					memory ) ) != FT_Err_Ok )
+					memory ) ) != HB_Err_Ok )
 	  goto Fail3;
       }
       else
       {
 	if ( curr_glyph == 0xFFFF )
 	{
-	  error = FT_Err_Invalid_Argument;
+	  error = HB_Err_Invalid_Argument;
 	  goto Fail3;
 	}
 	else
@@ -952,12 +953,12 @@ FT_Error  HB_GDEF_Build_ClassDefinition( HB_GDEFHeader*  gdef,
       if ( ( error = Make_ClassRange( gcd, start,
 				      curr_glyph - 1,
 				      curr_class,
-				      memory ) ) != FT_Err_Ok )
+				      memory ) ) != HB_Err_Ok )
 	goto Fail3;
 
       if ( curr_glyph > glyph_array[n] )
       {
-	error = FT_Err_Invalid_Argument;
+	error = HB_Err_Invalid_Argument;
 	goto Fail3;
       }
 
@@ -967,7 +968,7 @@ FT_Error  HB_GDEF_Build_ClassDefinition( HB_GDEFHeader*  gdef,
 
       if ( curr_class >= 5 )
       {
-	error = FT_Err_Invalid_Argument;
+	error = HB_Err_Invalid_Argument;
 	goto Fail3;
       }
 
@@ -976,14 +977,14 @@ FT_Error  HB_GDEF_Build_ClassDefinition( HB_GDEFHeader*  gdef,
 	if ( ( error = Make_ClassRange( gcd, start,
 					curr_glyph,
 					curr_class,
-					memory ) ) != FT_Err_Ok )
+					memory ) ) != HB_Err_Ok )
 	  goto Fail3;
       }
       else
       {
 	if ( curr_glyph == 0xFFFF )
 	{
-	  error = FT_Err_Invalid_Argument;
+	  error = HB_Err_Invalid_Argument;
 	  goto Fail3;
 	}
 	else
@@ -1046,7 +1047,7 @@ FT_Error  HB_GDEF_Build_ClassDefinition( HB_GDEFHeader*  gdef,
 
   gcd->loaded = TRUE;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   for ( m = 0; m < n; m++ )
@@ -1084,11 +1085,11 @@ static void  Free_NewGlyphClasses( HB_GDEFHeader*  gdef,
 }
 
 
-FT_Error  _HB_GDEF_Add_Glyph_Property( HB_GDEFHeader*  gdef,
+HB_Error  _HB_GDEF_Add_Glyph_Property( HB_GDEFHeader*  gdef,
 			      FT_UShort        glyphID,
 			      FT_UShort        property )
 {
-  FT_Error               error;
+  HB_Error               error;
   FT_UShort              class, new_class, index;
   FT_UShort              byte, bits, mask;
   FT_UShort              array_index, glyph_index, count;
@@ -1129,7 +1130,7 @@ FT_Error  _HB_GDEF_Add_Glyph_Property( HB_GDEFHeader*  gdef,
     break;
 
   default:
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
   }
 
   count = gdef->GlyphClassDef.cd.cd2.ClassRangeCount;
@@ -1165,16 +1166,16 @@ FT_Error  _HB_GDEF_Add_Glyph_Property( HB_GDEFHeader*  gdef,
     ngc[array_index][glyph_index / 4] |= bits;
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
-FT_Error  _HB_GDEF_Check_Property( HB_GDEFHeader*  gdef,
+HB_Error  _HB_GDEF_Check_Property( HB_GDEFHeader*  gdef,
 			  HB_GlyphItem    gitem,
 			  FT_UShort        flags,
 			  FT_UShort*       property )
 {
-  FT_Error  error;
+  HB_Error  error;
 
   if ( gdef )
   {
@@ -1221,7 +1222,7 @@ FT_Error  _HB_GDEF_Check_Property( HB_GDEFHeader*  gdef,
       *property = 0;
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
diff --git a/pango/opentype/harfbuzz-gdef.h b/pango/opentype/harfbuzz-gdef.h
index e126e826..59e14b97 100644
--- a/pango/opentype/harfbuzz-gdef.h
+++ b/pango/opentype/harfbuzz-gdef.h
@@ -100,22 +100,22 @@ typedef struct HB_GDEFHeader_   HB_GDEFHeader;
 typedef struct HB_GDEFHeader_*  HB_GDEF;
 
 
-FT_Error  HB_New_GDEF_Table( FT_Face          face,
+HB_Error  HB_New_GDEF_Table( FT_Face          face,
 			     HB_GDEFHeader** retptr );
       
 
-FT_Error  HB_Load_GDEF_Table( FT_Face          face,
+HB_Error  HB_Load_GDEF_Table( FT_Face          face,
 			      HB_GDEFHeader** gdef );
 
 
-FT_Error  HB_Done_GDEF_Table ( HB_GDEFHeader* gdef );
+HB_Error  HB_Done_GDEF_Table ( HB_GDEFHeader* gdef );
 
 
-FT_Error  HB_GDEF_Get_Glyph_Property( HB_GDEFHeader*  gdef,
+HB_Error  HB_GDEF_Get_Glyph_Property( HB_GDEFHeader*  gdef,
 				      FT_UShort        glyphID,
 				      FT_UShort*       property );
 
-FT_Error  HB_GDEF_Build_ClassDefinition( HB_GDEFHeader*  gdef,
+HB_Error  HB_GDEF_Build_ClassDefinition( HB_GDEFHeader*  gdef,
 					 FT_UShort        num_glyphs,
 					 FT_UShort        glyph_count,
 					 FT_UShort*       glyph_array,
diff --git a/pango/opentype/harfbuzz-gpos-private.h b/pango/opentype/harfbuzz-gpos-private.h
index a04416f5..a36f3a48 100644
--- a/pango/opentype/harfbuzz-gpos-private.h
+++ b/pango/opentype/harfbuzz-gpos-private.h
@@ -670,7 +670,7 @@ typedef union HB_GPOS_SubTable_  HB_GPOS_SubTable;
 
 
 
-FT_Error  _HB_GPOS_Load_SubTable( HB_GPOS_SubTable*  st,
+HB_Error  _HB_GPOS_Load_SubTable( HB_GPOS_SubTable*  st,
 				  FT_Stream     stream,
 				  FT_UShort     lookup_type );
 
diff --git a/pango/opentype/harfbuzz-gpos.c b/pango/opentype/harfbuzz-gpos.c
index 6f0476ab..e3486f0d 100644
--- a/pango/opentype/harfbuzz-gpos.c
+++ b/pango/opentype/harfbuzz-gpos.c
@@ -4,6 +4,7 @@
  *  David Turner, Robert Wilhelm, and Werner Lemberg.
  *
  *  Copyright 2006  Behdad Esfahbod
+ *  Copyright 2007  Red Hat Software
  *
  *  This is part of HarfBuzz, an OpenType Layout engine library.
  *
@@ -32,7 +33,7 @@ struct  GPOS_Instance_
 typedef struct GPOS_Instance_  GPOS_Instance;
 
 
-static FT_Error  GPOS_Do_Glyph_Lookup( GPOS_Instance*    gpi,
+static HB_Error  GPOS_Do_Glyph_Lookup( GPOS_Instance*    gpi,
 				       FT_UShort         lookup_index,
 				       HB_Buffer        buffer,
 				       FT_UShort         context_length,
@@ -43,7 +44,7 @@ static FT_Error  GPOS_Do_Glyph_Lookup( GPOS_Instance*    gpi,
 /* the client application must replace this with something more
    meaningful if multiple master fonts are to be supported.     */
 
-static FT_Error  default_mmfunc( FT_Face      face,
+static HB_Error  default_mmfunc( FT_Face      face,
 				 FT_UShort    metric_id,
 				 FT_Pos*      metric_value,
 				 void*        data )
@@ -52,12 +53,12 @@ static FT_Error  default_mmfunc( FT_Face      face,
   FT_UNUSED(metric_id);
   FT_UNUSED(metric_value);
   FT_UNUSED(data);
-  return HB_Err_No_MM_Interpreter;
+  return _hb_err(HB_Err_No_MM_Interpreter);
 }
 
 
 
-FT_Error  HB_Load_GPOS_Table( FT_Face          face,
+HB_Error  HB_Load_GPOS_Table( FT_Face          face,
 			      HB_GPOSHeader** retptr,
 			      HB_GDEFHeader*  gdef )
 {
@@ -68,15 +69,12 @@ FT_Error  HB_Load_GPOS_Table( FT_Face          face,
   HB_Lookup*      lo;
 
   FT_Stream  stream = face->stream;
-  FT_Error   error;
+  HB_Error   error;
   FT_Memory  memory = face->memory;
 
 
   if ( !retptr )
-    return FT_Err_Invalid_Argument;
-
-  if ( !stream )
-    return FT_Err_Invalid_Face_Handle;
+    return HB_Err_Invalid_Argument;
 
   if (( error = _hb_ftglue_face_goto_table( face, TTAG_GPOS, stream ) ))
     return error;
@@ -103,7 +101,7 @@ FT_Error  HB_Load_GPOS_Table( FT_Face          face,
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
        ( error = _HB_OPEN_Load_ScriptList( &gpos->ScriptList,
-				  stream ) ) != FT_Err_Ok )
+				  stream ) ) != HB_Err_Ok )
     goto Fail4;
   (void)FILE_Seek( cur_offset );
 
@@ -117,7 +115,7 @@ FT_Error  HB_Load_GPOS_Table( FT_Face          face,
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
        ( error = _HB_OPEN_Load_FeatureList( &gpos->FeatureList,
-				   stream ) ) != FT_Err_Ok )
+				   stream ) ) != HB_Err_Ok )
     goto Fail3;
   (void)FILE_Seek( cur_offset );
 
@@ -131,7 +129,7 @@ FT_Error  HB_Load_GPOS_Table( FT_Face          face,
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
        ( error = _HB_OPEN_Load_LookupList( &gpos->LookupList,
-				  stream, HB_Type_GPOS ) ) != FT_Err_Ok )
+				  stream, HB_Type_GPOS ) ) != HB_Err_Ok )
     goto Fail2;
 
   gpos->gdef = gdef;      /* can be NULL */
@@ -157,7 +155,7 @@ FT_Error  HB_Load_GPOS_Table( FT_Face          face,
       {
 	if ( FILE_Seek( gdef->MarkAttachClassDef_offset ) ||
 	     ( error = _HB_OPEN_Load_ClassDefinition( &gdef->MarkAttachClassDef,
-					     256, stream ) ) != FT_Err_Ok )
+					     256, stream ) ) != HB_Err_Ok )
 	  goto Fail1;
 
 	break;
@@ -167,7 +165,7 @@ FT_Error  HB_Load_GPOS_Table( FT_Face          face,
 
   *retptr = gpos;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   _HB_OPEN_Free_LookupList( &gpos->LookupList, HB_Type_GPOS, memory );
@@ -185,7 +183,7 @@ Fail4:
 }
 
 
-FT_Error  HB_Done_GPOS_Table( HB_GPOSHeader* gpos )
+HB_Error  HB_Done_GPOS_Table( HB_GPOSHeader* gpos )
 {
   FT_Memory memory = gpos->memory;
 
@@ -195,7 +193,7 @@ FT_Error  HB_Done_GPOS_Table( HB_GPOSHeader* gpos )
 
   FREE( gpos );
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
@@ -211,12 +209,12 @@ FT_Error  HB_Done_GPOS_Table( HB_GPOSHeader* gpos )
    `record' -- offsets for device tables in ValueRecords are taken from
    the parent table and not the parent record.                          */
 
-static FT_Error  Load_ValueRecord( HB_ValueRecord*  vr,
+static HB_Error  Load_ValueRecord( HB_ValueRecord*  vr,
 				   FT_UShort         format,
 				   FT_ULong          base_offset,
 				   FT_Stream         stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_Memory memory = stream->memory;
 
   FT_ULong cur_offset, new_offset;
@@ -286,7 +284,7 @@ static FT_Error  Load_ValueRecord( HB_ValueRecord*  vr,
       cur_offset = FILE_Pos();
       if ( FILE_Seek( new_offset ) ||
 	   ( error = _HB_OPEN_Load_Device( &vr->XPlacementDevice,
-				  stream ) ) != FT_Err_Ok )
+				  stream ) ) != HB_Err_Ok )
 	return error;
       (void)FILE_Seek( cur_offset );
     }
@@ -317,7 +315,7 @@ static FT_Error  Load_ValueRecord( HB_ValueRecord*  vr,
       cur_offset = FILE_Pos();
       if ( FILE_Seek( new_offset ) ||
 	   ( error = _HB_OPEN_Load_Device( &vr->YPlacementDevice,
-				  stream ) ) != FT_Err_Ok )
+				  stream ) ) != HB_Err_Ok )
 	goto Fail3;
       (void)FILE_Seek( cur_offset );
     }
@@ -348,7 +346,7 @@ static FT_Error  Load_ValueRecord( HB_ValueRecord*  vr,
       cur_offset = FILE_Pos();
       if ( FILE_Seek( new_offset ) ||
 	   ( error = _HB_OPEN_Load_Device( &vr->XAdvanceDevice,
-				  stream ) ) != FT_Err_Ok )
+				  stream ) ) != HB_Err_Ok )
 	goto Fail2;
       (void)FILE_Seek( cur_offset );
     }
@@ -379,7 +377,7 @@ static FT_Error  Load_ValueRecord( HB_ValueRecord*  vr,
       cur_offset = FILE_Pos();
       if ( FILE_Seek( new_offset ) ||
 	   ( error = _HB_OPEN_Load_Device( &vr->YAdvanceDevice,
-				  stream ) ) != FT_Err_Ok )
+				  stream ) ) != HB_Err_Ok )
 	goto Fail1;
       (void)FILE_Seek( cur_offset );
     }
@@ -442,7 +440,7 @@ static FT_Error  Load_ValueRecord( HB_ValueRecord*  vr,
   else
     vr->YIdAdvance = 0;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   _HB_OPEN_Free_Device( &vr->YAdvanceDevice, memory );
@@ -471,14 +469,14 @@ static void  Free_ValueRecord( HB_ValueRecord*  vr,
 }
 
 
-static FT_Error  Get_ValueRecord( GPOS_Instance*    gpi,
+static HB_Error  Get_ValueRecord( GPOS_Instance*    gpi,
 				  HB_ValueRecord*  vr,
 				  FT_UShort         format,
 				  HB_Position      gd )
 {
   FT_Pos           value;
   FT_Short         pixel_value;
-  FT_Error         error = FT_Err_Ok;
+  HB_Error         error = HB_Err_Ok;
   HB_GPOSHeader*  gpos = gpi->gpos;
 
   FT_UShort  x_ppem, y_ppem;
@@ -486,7 +484,7 @@ static FT_Error  Get_ValueRecord( GPOS_Instance*    gpi,
 
 
   if ( !format )
-    return FT_Err_Ok;
+    return HB_Err_Ok;
 
   x_ppem  = gpi->face->size->metrics.x_ppem;
   y_ppem  = gpi->face->size->metrics.y_ppem;
@@ -574,10 +572,10 @@ static FT_Error  Get_ValueRecord( GPOS_Instance*    gpi,
 /* AnchorFormat3 */
 /* AnchorFormat4 */
 
-static FT_Error  Load_Anchor( HB_Anchor*  an,
+static HB_Error  Load_Anchor( HB_Anchor*  an,
 			      FT_Stream    stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_Memory memory = stream->memory;
 
   FT_ULong cur_offset, new_offset, base_offset;
@@ -633,7 +631,7 @@ static FT_Error  Load_Anchor( HB_Anchor*  an,
       cur_offset = FILE_Pos();
       if ( FILE_Seek( new_offset ) ||
 	   ( error = _HB_OPEN_Load_Device( &an->af.af3.XDeviceTable,
-				  stream ) ) != FT_Err_Ok )
+				  stream ) ) != HB_Err_Ok )
 	return error;
       (void)FILE_Seek( cur_offset );
     }
@@ -658,7 +656,7 @@ static FT_Error  Load_Anchor( HB_Anchor*  an,
       cur_offset = FILE_Pos();
       if ( FILE_Seek( new_offset ) ||
 	   ( error = _HB_OPEN_Load_Device( &an->af.af3.YDeviceTable,
-				  stream ) ) != FT_Err_Ok )
+				  stream ) ) != HB_Err_Ok )
 	goto Fail;
       (void)FILE_Seek( cur_offset );
     }
@@ -681,10 +679,10 @@ static FT_Error  Load_Anchor( HB_Anchor*  an,
     break;
 
   default:
-    return HB_Err_Invalid_GPOS_SubTable_Format;
+    return _hb_err(HB_Err_Invalid_GPOS_SubTable_Format);
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail:
   _HB_OPEN_Free_Device( &an->af.af3.XDeviceTable, memory );
@@ -703,13 +701,13 @@ static void  Free_Anchor( HB_Anchor*  an,
 }
 
 
-static FT_Error  Get_Anchor( GPOS_Instance*   gpi,
+static HB_Error  Get_Anchor( GPOS_Instance*   gpi,
 			     HB_Anchor*      an,
 			     FT_UShort        glyph_index,
 			     FT_Pos*          x_value,
 			     FT_Pos*          y_value )
 {
-  FT_Error  error = FT_Err_Ok;
+  HB_Error  error = HB_Err_Ok;
 
   FT_Outline       outline;
   HB_GPOSHeader*  gpos = gpi->gpos;
@@ -731,6 +729,7 @@ static FT_Error  Get_Anchor( GPOS_Instance*   gpi,
   {
   case 0:
     /* The special case of an empty AnchorTable */
+  default:
 
     return HB_Err_Not_Covered;
 
@@ -751,7 +750,7 @@ static FT_Error  Get_Anchor( GPOS_Instance*   gpi,
 	return error;
 
       if ( gpi->face->glyph->format != ft_glyph_format_outline )
-	return HB_Err_Invalid_GPOS_SubTable;
+	return _hb_err(HB_Err_Invalid_GPOS_SubTable);
 
       ap = an->af.af2.AnchorPoint;
 
@@ -765,7 +764,7 @@ static FT_Error  Get_Anchor( GPOS_Instance*   gpi,
 	goto no_contour_point;
 
       if ( ap >= outline.n_points )
-	return HB_Err_Invalid_GPOS_SubTable;
+	return _hb_err(HB_Err_Invalid_GPOS_SubTable);
 
       *x_value = outline.points[ap].x;
       *y_value = outline.points[ap].y;
@@ -812,10 +811,10 @@ static FT_Error  Get_Anchor( GPOS_Instance*   gpi,
 
 /* MarkArray */
 
-static FT_Error  Load_MarkArray ( HB_MarkArray*  ma,
+static HB_Error  Load_MarkArray ( HB_MarkArray*  ma,
 				  FT_Stream       stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_Memory memory = stream->memory;
 
   FT_UShort        n, m, count;
@@ -852,12 +851,12 @@ static FT_Error  Load_MarkArray ( HB_MarkArray*  ma,
 
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
-	 ( error = Load_Anchor( &mr[n].MarkAnchor, stream ) ) != FT_Err_Ok )
+	 ( error = Load_Anchor( &mr[n].MarkAnchor, stream ) ) != HB_Err_Ok )
       goto Fail;
     (void)FILE_Seek( cur_offset );
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail:
   for ( m = 0; m < n; m++ )
@@ -894,10 +893,10 @@ static void  Free_MarkArray( HB_MarkArray*  ma,
 /* SinglePosFormat1 */
 /* SinglePosFormat2 */
 
-static FT_Error  Load_SinglePos( HB_GPOS_SubTable* st,
+static HB_Error  Load_SinglePos( HB_GPOS_SubTable* st,
 				 FT_Stream       stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_Memory memory = stream->memory;
   HB_SinglePos*   sp = &st->single;
 
@@ -920,11 +919,11 @@ static FT_Error  Load_SinglePos( HB_GPOS_SubTable* st,
   FORGET_Frame();
 
   if ( !format )
-    return HB_Err_Invalid_GPOS_SubTable;
+    return _hb_err(HB_Err_Invalid_GPOS_SubTable);
 
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
-       ( error = _HB_OPEN_Load_Coverage( &sp->Coverage, stream ) ) != FT_Err_Ok )
+       ( error = _HB_OPEN_Load_Coverage( &sp->Coverage, stream ) ) != HB_Err_Ok )
     return error;
   (void)FILE_Seek( cur_offset );
 
@@ -961,10 +960,10 @@ static FT_Error  Load_SinglePos( HB_GPOS_SubTable* st,
     break;
 
   default:
-    return HB_Err_Invalid_GPOS_SubTable_Format;
+    return _hb_err(HB_Err_Invalid_GPOS_SubTable_Format);
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   for ( m = 0; m < n; m++ )
@@ -1007,28 +1006,14 @@ static void  Free_SinglePos( HB_GPOS_SubTable* st,
       FREE( v );
     }
     break;
+  default:
+    break;
   }
 
   _HB_OPEN_Free_Coverage( &sp->Coverage, memory );
 }
 
-static FT_Error  Lookup_DefaultPos(  GPOS_Instance*    gpi,
-				     HB_GPOS_SubTable* st,
-				     HB_Buffer        buffer,
-				     FT_UShort         flags,
-				     FT_UShort         context_length,
-				     int               nesting_level )
-{
-  FT_UNUSED(gpi);
-  FT_UNUSED(st);
-  FT_UNUSED(buffer);
-  FT_UNUSED(flags);
-  FT_UNUSED(context_length);
-  FT_UNUSED(nesting_level);
-  return HB_Err_Not_Covered;
-}
-
-static FT_Error  Lookup_SinglePos( GPOS_Instance*    gpi,
+static HB_Error  Lookup_SinglePos( GPOS_Instance*    gpi,
 				   HB_GPOS_SubTable* st,
 				   HB_Buffer        buffer,
 				   FT_UShort         flags,
@@ -1036,7 +1021,7 @@ static FT_Error  Lookup_SinglePos( GPOS_Instance*    gpi,
 				   int               nesting_level )
 {
   FT_UShort        index, property;
-  FT_Error         error;
+  HB_Error         error;
   HB_GPOSHeader*  gpos = gpi->gpos;
   HB_SinglePos*   sp = &st->single;
 
@@ -1063,7 +1048,7 @@ static FT_Error  Lookup_SinglePos( GPOS_Instance*    gpi,
 
   case 2:
     if ( index >= sp->spf.spf2.ValueCount )
-      return HB_Err_Invalid_GPOS_SubTable;
+      return _hb_err(HB_Err_Invalid_GPOS_SubTable);
     error = Get_ValueRecord( gpi, &sp->spf.spf2.Value[index],
 			     sp->ValueFormat, POSITION( buffer->in_pos ) );
     if ( error )
@@ -1071,12 +1056,12 @@ static FT_Error  Lookup_SinglePos( GPOS_Instance*    gpi,
     break;
 
   default:
-    return HB_Err_Invalid_GPOS_SubTable;
+    return _hb_err(HB_Err_Invalid_GPOS_SubTable);
   }
 
   (buffer->in_pos)++;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
@@ -1084,12 +1069,12 @@ static FT_Error  Lookup_SinglePos( GPOS_Instance*    gpi,
 
 /* PairSet */
 
-static FT_Error  Load_PairSet ( HB_PairSet*  ps,
+static HB_Error  Load_PairSet ( HB_PairSet*  ps,
 				FT_UShort     format1,
 				FT_UShort     format2,
 				FT_Stream     stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_Memory memory = stream->memory;
 
   FT_UShort             n, m, count;
@@ -1143,7 +1128,7 @@ static FT_Error  Load_PairSet ( HB_PairSet*  ps,
     }
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail:
   for ( m = 0; m < n; m++ )
@@ -1189,12 +1174,12 @@ static void  Free_PairSet( HB_PairSet*  ps,
 
 /* PairPosFormat1 */
 
-static FT_Error  Load_PairPos1( HB_PairPosFormat1*  ppf1,
+static HB_Error  Load_PairPos1( HB_PairPosFormat1*  ppf1,
 				FT_UShort            format1,
 				FT_UShort            format2,
 				FT_Stream            stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_Memory memory = stream->memory;
 
   FT_UShort     n, m, count;
@@ -1231,12 +1216,12 @@ static FT_Error  Load_PairPos1( HB_PairPosFormat1*  ppf1,
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
 	 ( error = Load_PairSet( &ps[n], format1,
-				 format2, stream ) ) != FT_Err_Ok )
+				 format2, stream ) ) != HB_Err_Ok )
       goto Fail;
     (void)FILE_Seek( cur_offset );
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail:
   for ( m = 0; m < n; m++ )
@@ -1272,12 +1257,12 @@ static void  Free_PairPos1( HB_PairPosFormat1*  ppf1,
 
 /* PairPosFormat2 */
 
-static FT_Error  Load_PairPos2( HB_PairPosFormat2*  ppf2,
+static HB_Error  Load_PairPos2( HB_PairPosFormat2*  ppf2,
 				FT_UShort            format1,
 				FT_UShort            format2,
 				FT_Stream            stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_Memory memory = stream->memory;
 
   FT_UShort          m, n, k, count1, count2;
@@ -1306,11 +1291,11 @@ static FT_Error  Load_PairPos2( HB_PairPosFormat2*  ppf2,
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset1 ) ||
        ( error = _HB_OPEN_Load_ClassDefinition( &ppf2->ClassDef1, count1,
-				       stream ) ) != FT_Err_Ok )
+				       stream ) ) != HB_Err_Ok )
     return error;
   if ( FILE_Seek( new_offset2 ) ||
        ( error = _HB_OPEN_Load_ClassDefinition( &ppf2->ClassDef2, count2,
-				       stream ) ) != FT_Err_Ok )
+				       stream ) ) != HB_Err_Ok )
     goto Fail3;
   (void)FILE_Seek( cur_offset );
 
@@ -1365,7 +1350,7 @@ static FT_Error  Load_PairPos2( HB_PairPosFormat2*  ppf2,
     goto Fail1;
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   for ( k = 0; k < m; k++ )
@@ -1434,10 +1419,10 @@ static void  Free_PairPos2( HB_PairPosFormat2*  ppf2,
 }
 
 
-static FT_Error  Load_PairPos( HB_GPOS_SubTable* st,
+static HB_Error  Load_PairPos( HB_GPOS_SubTable* st,
 			       FT_Stream     stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_Memory memory = stream->memory;
   HB_PairPos*     pp = &st->pair;
 
@@ -1460,7 +1445,7 @@ static FT_Error  Load_PairPos( HB_GPOS_SubTable* st,
 
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
-       ( error = _HB_OPEN_Load_Coverage( &pp->Coverage, stream ) ) != FT_Err_Ok )
+       ( error = _HB_OPEN_Load_Coverage( &pp->Coverage, stream ) ) != HB_Err_Ok )
     return error;
   (void)FILE_Seek( cur_offset );
 
@@ -1479,10 +1464,10 @@ static FT_Error  Load_PairPos( HB_GPOS_SubTable* st,
     break;
 
   default:
-    return HB_Err_Invalid_GPOS_SubTable_Format;
+    return _hb_err(HB_Err_Invalid_GPOS_SubTable_Format);
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail:
   _HB_OPEN_Free_Coverage( &pp->Coverage, memory );
@@ -1509,13 +1494,16 @@ static void  Free_PairPos( HB_GPOS_SubTable* st,
   case 2:
     Free_PairPos2( &pp->ppf.ppf2, format1, format2, memory );
     break;
+
+  default:
+    break;
   }
 
   _HB_OPEN_Free_Coverage( &pp->Coverage, memory );
 }
 
 
-static FT_Error  Lookup_PairPos1( GPOS_Instance*       gpi,
+static HB_Error  Lookup_PairPos1( GPOS_Instance*       gpi,
 				  HB_PairPosFormat1*  ppf1,
 				  HB_Buffer           buffer,
 				  FT_ULong             first_pos,
@@ -1523,18 +1511,18 @@ static FT_Error  Lookup_PairPos1( GPOS_Instance*       gpi,
 				  FT_UShort            format1,
 				  FT_UShort            format2 )
 {
-  FT_Error              error;
+  HB_Error              error;
   FT_UShort             numpvr, glyph2;
 
   HB_PairValueRecord*  pvr;
 
 
   if ( index >= ppf1->PairSetCount )
-     return HB_Err_Invalid_GPOS_SubTable;
+     return _hb_err(HB_Err_Invalid_GPOS_SubTable);
 
   pvr = ppf1->PairSet[index].PairValueRecord;
   if ( !pvr )
-    return HB_Err_Invalid_GPOS_SubTable;
+    return _hb_err(HB_Err_Invalid_GPOS_SubTable);
 
   glyph2 = IN_CURGLYPH();
 
@@ -1557,14 +1545,14 @@ static FT_Error  Lookup_PairPos1( GPOS_Instance*       gpi,
 }
 
 
-static FT_Error  Lookup_PairPos2( GPOS_Instance*       gpi,
+static HB_Error  Lookup_PairPos2( GPOS_Instance*       gpi,
 				  HB_PairPosFormat2*  ppf2,
 				  HB_Buffer           buffer,
 				  FT_ULong             first_pos,
 				  FT_UShort            format1,
 				  FT_UShort            format2 )
 {
-  FT_Error           error;
+  HB_Error           error;
   FT_UShort          cl1, cl2;
 
   HB_Class1Record*  c1r;
@@ -1582,7 +1570,7 @@ static FT_Error  Lookup_PairPos2( GPOS_Instance*       gpi,
 
   c1r = &ppf2->Class1Record[cl1];
   if ( !c1r )
-    return HB_Err_Invalid_GPOS_SubTable;
+    return _hb_err(HB_Err_Invalid_GPOS_SubTable);
   c2r = &c1r->Class2Record[cl2];
 
   error = Get_ValueRecord( gpi, &c2r->Value1, format1, POSITION( first_pos ) );
@@ -1592,14 +1580,14 @@ static FT_Error  Lookup_PairPos2( GPOS_Instance*       gpi,
 }
 
 
-static FT_Error  Lookup_PairPos( GPOS_Instance*    gpi,
+static HB_Error  Lookup_PairPos( GPOS_Instance*    gpi,
 				 HB_GPOS_SubTable* st,
 				 HB_Buffer        buffer,
 				 FT_UShort         flags,
 				 FT_UShort         context_length,
 				 int               nesting_level )
 {
-  FT_Error         error;
+  HB_Error         error;
   FT_UShort        index, property;
   FT_ULong         first_pos;
   HB_GPOSHeader*  gpos = gpi->gpos;
@@ -1654,7 +1642,7 @@ static FT_Error  Lookup_PairPos( GPOS_Instance*    gpi,
     break;
 
   default:
-    return HB_Err_Invalid_GPOS_SubTable_Format;
+    return _hb_err(HB_Err_Invalid_GPOS_SubTable_Format);
   }
 
   /* if we don't have coverage for the second glyph don't skip it for
@@ -1676,10 +1664,10 @@ static FT_Error  Lookup_PairPos( GPOS_Instance*    gpi,
 
 /* CursivePosFormat1 */
 
-static FT_Error  Load_CursivePos( HB_GPOS_SubTable* st,
+static HB_Error  Load_CursivePos( HB_GPOS_SubTable* st,
 				  FT_Stream        stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_Memory memory = stream->memory;
   HB_CursivePos*  cp = &st->cursive;
 
@@ -1701,7 +1689,7 @@ static FT_Error  Load_CursivePos( HB_GPOS_SubTable* st,
 
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
-       ( error = _HB_OPEN_Load_Coverage( &cp->Coverage, stream ) ) != FT_Err_Ok )
+       ( error = _HB_OPEN_Load_Coverage( &cp->Coverage, stream ) ) != HB_Err_Ok )
     return error;
   (void)FILE_Seek( cur_offset );
 
@@ -1737,7 +1725,7 @@ static FT_Error  Load_CursivePos( HB_GPOS_SubTable* st,
       cur_offset = FILE_Pos();
       if ( FILE_Seek( new_offset ) ||
 	   ( error = Load_Anchor( &eer[n].EntryAnchor,
-				  stream ) ) != FT_Err_Ok )
+				  stream ) ) != HB_Err_Ok )
 	goto Fail1;
       (void)FILE_Seek( cur_offset );
     }
@@ -1758,7 +1746,7 @@ static FT_Error  Load_CursivePos( HB_GPOS_SubTable* st,
       cur_offset = FILE_Pos();
       if ( FILE_Seek( new_offset ) ||
 	   ( error = Load_Anchor( &eer[n].ExitAnchor,
-				  stream ) ) != FT_Err_Ok )
+				  stream ) ) != HB_Err_Ok )
       {
 	if ( entry_offset )
 	  Free_Anchor( &eer[n].EntryAnchor, memory );
@@ -1770,7 +1758,7 @@ static FT_Error  Load_CursivePos( HB_GPOS_SubTable* st,
       eer[n].ExitAnchor.PosFormat   = 0;
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   for ( m = 0; m < n; m++ )
@@ -1814,7 +1802,7 @@ static void  Free_CursivePos( HB_GPOS_SubTable* st,
 }
 
 
-static FT_Error  Lookup_CursivePos( GPOS_Instance*    gpi,
+static HB_Error  Lookup_CursivePos( GPOS_Instance*    gpi,
 				    HB_GPOS_SubTable* st,
 				    HB_Buffer        buffer,
 				    FT_UShort         flags,
@@ -1822,7 +1810,7 @@ static FT_Error  Lookup_CursivePos( GPOS_Instance*    gpi,
 				    int               nesting_level )
 {
   FT_UShort        index, property;
-  FT_Error         error;
+  HB_Error         error;
   HB_GPOSHeader*  gpos = gpi->gpos;
   HB_CursivePos*  cp = &st->cursive;
 
@@ -1861,7 +1849,7 @@ static FT_Error  Lookup_CursivePos( GPOS_Instance*    gpi,
   }
 
   if ( index >= cp->EntryExitCount )
-    return HB_Err_Invalid_GPOS_SubTable;
+    return _hb_err(HB_Err_Invalid_GPOS_SubTable);
 
   eer = &cp->EntryExitRecord[index];
 
@@ -2033,7 +2021,7 @@ end:
 
   (buffer->in_pos)++;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
@@ -2041,11 +2029,11 @@ end:
 
 /* BaseArray */
 
-static FT_Error  Load_BaseArray( HB_BaseArray*  ba,
+static HB_Error  Load_BaseArray( HB_BaseArray*  ba,
 				 FT_UShort       num_classes,
 				 FT_Stream       stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_Memory memory = stream->memory;
 
   FT_UShort        m, n, k, count;
@@ -2090,14 +2078,17 @@ static FT_Error  Load_BaseArray( HB_BaseArray*  ba,
       FORGET_Frame();
 
       if (new_offset == base_offset) {
-	/* Doulos SIL Regular is buggy and has zer offsets here.  Skip */
+	/* XXX
+	 * Doulos SIL Regular is buggy and has zero offsets here.
+	 * Skip it
+	 */
 	ban[n].PosFormat = 0;
 	continue;
       }
 
       cur_offset = FILE_Pos();
       if ( FILE_Seek( new_offset ) ||
-	   ( error = Load_Anchor( &ban[n], stream ) ) != FT_Err_Ok )
+	   ( error = Load_Anchor( &ban[n], stream ) ) != HB_Err_Ok )
 	goto Fail0;
       (void)FILE_Seek( cur_offset );
     }
@@ -2109,7 +2100,7 @@ static FT_Error  Load_BaseArray( HB_BaseArray*  ba,
     goto Fail;
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail:
   for ( k = 0; k < m; k++ )
@@ -2159,10 +2150,10 @@ static void  Free_BaseArray( HB_BaseArray*  ba,
 
 /* MarkBasePosFormat1 */
 
-static FT_Error  Load_MarkBasePos( HB_GPOS_SubTable* st,
+static HB_Error  Load_MarkBasePos( HB_GPOS_SubTable* st,
 				   FT_Stream         stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_Memory memory = stream->memory;
   HB_MarkBasePos* mbp = &st->markbase;
 
@@ -2180,11 +2171,11 @@ static FT_Error  Load_MarkBasePos( HB_GPOS_SubTable* st,
   FORGET_Frame();
 
   if (mbp->PosFormat != 1)
-    return HB_Err_Invalid_SubTable_Format;
+    return _hb_err(HB_Err_Invalid_SubTable_Format);
 
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
-       ( error = _HB_OPEN_Load_Coverage( &mbp->MarkCoverage, stream ) ) != FT_Err_Ok )
+       ( error = _HB_OPEN_Load_Coverage( &mbp->MarkCoverage, stream ) ) != HB_Err_Ok )
     return error;
   (void)FILE_Seek( cur_offset );
 
@@ -2197,7 +2188,7 @@ static FT_Error  Load_MarkBasePos( HB_GPOS_SubTable* st,
 
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
-       ( error = _HB_OPEN_Load_Coverage( &mbp->BaseCoverage, stream ) ) != FT_Err_Ok )
+       ( error = _HB_OPEN_Load_Coverage( &mbp->BaseCoverage, stream ) ) != HB_Err_Ok )
     goto Fail3;
   (void)FILE_Seek( cur_offset );
 
@@ -2211,7 +2202,7 @@ static FT_Error  Load_MarkBasePos( HB_GPOS_SubTable* st,
 
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
-       ( error = Load_MarkArray( &mbp->MarkArray, stream ) ) != FT_Err_Ok )
+       ( error = Load_MarkArray( &mbp->MarkArray, stream ) ) != HB_Err_Ok )
     goto Fail2;
   (void)FILE_Seek( cur_offset );
 
@@ -2225,10 +2216,10 @@ static FT_Error  Load_MarkBasePos( HB_GPOS_SubTable* st,
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
        ( error = Load_BaseArray( &mbp->BaseArray, mbp->ClassCount,
-				 stream ) ) != FT_Err_Ok )
+				 stream ) ) != HB_Err_Ok )
     goto Fail1;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   Free_MarkArray( &mbp->MarkArray, memory );
@@ -2254,7 +2245,7 @@ static void  Free_MarkBasePos( HB_GPOS_SubTable* st,
 }
 
 
-static FT_Error  Lookup_MarkBasePos( GPOS_Instance*    gpi,
+static HB_Error  Lookup_MarkBasePos( GPOS_Instance*    gpi,
 				     HB_GPOS_SubTable* st,
 				     HB_Buffer        buffer,
 				     FT_UShort         flags,
@@ -2263,7 +2254,7 @@ static FT_Error  Lookup_MarkBasePos( GPOS_Instance*    gpi,
 {
   FT_UShort        i, j, mark_index, base_index, property, class;
   FT_Pos           x_mark_value, y_mark_value, x_base_value, y_base_value;
-  FT_Error         error;
+  HB_Error         error;
   HB_GPOSHeader*  gpos = gpi->gpos;
   HB_MarkBasePos* mbp = &st->markbase;
 
@@ -2328,18 +2319,18 @@ static FT_Error  Lookup_MarkBasePos( GPOS_Instance*    gpi,
   ma = &mbp->MarkArray;
 
   if ( mark_index >= ma->MarkCount )
-    return HB_Err_Invalid_GPOS_SubTable;
+    return _hb_err(HB_Err_Invalid_GPOS_SubTable);
 
   class       = ma->MarkRecord[mark_index].Class;
   mark_anchor = &ma->MarkRecord[mark_index].MarkAnchor;
 
   if ( class >= mbp->ClassCount )
-    return HB_Err_Invalid_GPOS_SubTable;
+    return _hb_err(HB_Err_Invalid_GPOS_SubTable);
 
   ba = &mbp->BaseArray;
 
   if ( base_index >= ba->BaseCount )
-    return HB_Err_Invalid_GPOS_SubTable;
+    return _hb_err(HB_Err_Invalid_GPOS_SubTable);
 
   br          = &ba->BaseRecord[base_index];
   base_anchor = &br->BaseAnchor[class];
@@ -2366,7 +2357,7 @@ static FT_Error  Lookup_MarkBasePos( GPOS_Instance*    gpi,
 
   (buffer->in_pos)++;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
@@ -2374,11 +2365,11 @@ static FT_Error  Lookup_MarkBasePos( GPOS_Instance*    gpi,
 
 /* LigatureAttach */
 
-static FT_Error  Load_LigatureAttach( HB_LigatureAttach*  lat,
+static HB_Error  Load_LigatureAttach( HB_LigatureAttach*  lat,
 				      FT_UShort            num_classes,
 				      FT_Stream            stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_Memory memory = stream->memory;
 
   FT_UShort             m, n, k, count;
@@ -2428,7 +2419,7 @@ static FT_Error  Load_LigatureAttach( HB_LigatureAttach*  lat,
 
 	cur_offset = FILE_Pos();
 	if ( FILE_Seek( new_offset ) ||
-	     ( error = Load_Anchor( &lan[n], stream ) ) != FT_Err_Ok )
+	     ( error = Load_Anchor( &lan[n], stream ) ) != HB_Err_Ok )
 	  goto Fail0;
 	(void)FILE_Seek( cur_offset );
       }
@@ -2443,7 +2434,7 @@ static FT_Error  Load_LigatureAttach( HB_LigatureAttach*  lat,
     goto Fail;
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail:
   for ( k = 0; k < m; k++ )
@@ -2493,11 +2484,11 @@ static void  Free_LigatureAttach( HB_LigatureAttach*  lat,
 
 /* LigatureArray */
 
-static FT_Error  Load_LigatureArray( HB_LigatureArray*  la,
+static HB_Error  Load_LigatureArray( HB_LigatureArray*  la,
 				     FT_UShort           num_classes,
 				     FT_Stream           stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_Memory memory = stream->memory;
 
   FT_UShort            n, m, count;
@@ -2534,12 +2525,12 @@ static FT_Error  Load_LigatureArray( HB_LigatureArray*  la,
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
 	 ( error = Load_LigatureAttach( &lat[n], num_classes,
-					stream ) ) != FT_Err_Ok )
+					stream ) ) != HB_Err_Ok )
       goto Fail;
     (void)FILE_Seek( cur_offset );
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail:
   for ( m = 0; m < n; m++ )
@@ -2574,10 +2565,10 @@ static void  Free_LigatureArray( HB_LigatureArray*  la,
 
 /* MarkLigPosFormat1 */
 
-static FT_Error  Load_MarkLigPos( HB_GPOS_SubTable* st,
+static HB_Error  Load_MarkLigPos( HB_GPOS_SubTable* st,
 				  FT_Stream        stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_Memory memory = stream->memory;
   HB_MarkLigPos*  mlp = &st->marklig;
 
@@ -2596,7 +2587,7 @@ static FT_Error  Load_MarkLigPos( HB_GPOS_SubTable* st,
 
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
-       ( error = _HB_OPEN_Load_Coverage( &mlp->MarkCoverage, stream ) ) != FT_Err_Ok )
+       ( error = _HB_OPEN_Load_Coverage( &mlp->MarkCoverage, stream ) ) != HB_Err_Ok )
     return error;
   (void)FILE_Seek( cur_offset );
 
@@ -2610,7 +2601,7 @@ static FT_Error  Load_MarkLigPos( HB_GPOS_SubTable* st,
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
        ( error = _HB_OPEN_Load_Coverage( &mlp->LigatureCoverage,
-				stream ) ) != FT_Err_Ok )
+				stream ) ) != HB_Err_Ok )
     goto Fail3;
   (void)FILE_Seek( cur_offset );
 
@@ -2624,7 +2615,7 @@ static FT_Error  Load_MarkLigPos( HB_GPOS_SubTable* st,
 
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
-       ( error = Load_MarkArray( &mlp->MarkArray, stream ) ) != FT_Err_Ok )
+       ( error = Load_MarkArray( &mlp->MarkArray, stream ) ) != HB_Err_Ok )
     goto Fail2;
   (void)FILE_Seek( cur_offset );
 
@@ -2638,10 +2629,10 @@ static FT_Error  Load_MarkLigPos( HB_GPOS_SubTable* st,
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
        ( error = Load_LigatureArray( &mlp->LigatureArray, mlp->ClassCount,
-				     stream ) ) != FT_Err_Ok )
+				     stream ) ) != HB_Err_Ok )
     goto Fail1;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   Free_MarkArray( &mlp->MarkArray, memory );
@@ -2667,7 +2658,7 @@ static void  Free_MarkLigPos( HB_GPOS_SubTable* st,
 }
 
 
-static FT_Error  Lookup_MarkLigPos( GPOS_Instance*    gpi,
+static HB_Error  Lookup_MarkLigPos( GPOS_Instance*    gpi,
 				    HB_GPOS_SubTable* st,
 				    HB_Buffer        buffer,
 				    FT_UShort         flags,
@@ -2677,7 +2668,7 @@ static FT_Error  Lookup_MarkLigPos( GPOS_Instance*    gpi,
   FT_UShort        i, j, mark_index, lig_index, property, class;
   FT_UShort        mark_glyph;
   FT_Pos           x_mark_value, y_mark_value, x_lig_value, y_lig_value;
-  FT_Error         error;
+  HB_Error         error;
   HB_GPOSHeader*  gpos = gpi->gpos;
   HB_MarkLigPos*  mlp = &st->marklig;
 
@@ -2745,18 +2736,18 @@ static FT_Error  Lookup_MarkLigPos( GPOS_Instance*    gpi,
   ma = &mlp->MarkArray;
 
   if ( mark_index >= ma->MarkCount )
-    return HB_Err_Invalid_GPOS_SubTable;
+    return _hb_err(HB_Err_Invalid_GPOS_SubTable);
 
   class       = ma->MarkRecord[mark_index].Class;
   mark_anchor = &ma->MarkRecord[mark_index].MarkAnchor;
 
   if ( class >= mlp->ClassCount )
-    return HB_Err_Invalid_GPOS_SubTable;
+    return _hb_err(HB_Err_Invalid_GPOS_SubTable);
 
   la = &mlp->LigatureArray;
 
   if ( lig_index >= la->LigatureCount )
-    return HB_Err_Invalid_GPOS_SubTable;
+    return _hb_err(HB_Err_Invalid_GPOS_SubTable);
 
   lat = &la->LigatureAttach[lig_index];
 
@@ -2798,7 +2789,7 @@ static FT_Error  Lookup_MarkLigPos( GPOS_Instance*    gpi,
 
   (buffer->in_pos)++;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
@@ -2806,11 +2797,11 @@ static FT_Error  Lookup_MarkLigPos( GPOS_Instance*    gpi,
 
 /* Mark2Array */
 
-static FT_Error  Load_Mark2Array( HB_Mark2Array*  m2a,
+static HB_Error  Load_Mark2Array( HB_Mark2Array*  m2a,
 				  FT_UShort        num_classes,
 				  FT_Stream        stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_Memory memory = stream->memory;
 
   FT_UShort         k, m, n, count;
@@ -2856,7 +2847,7 @@ static FT_Error  Load_Mark2Array( HB_Mark2Array*  m2a,
 
       cur_offset = FILE_Pos();
       if ( FILE_Seek( new_offset ) ||
-	   ( error = Load_Anchor( &m2an[n], stream ) ) != FT_Err_Ok )
+	   ( error = Load_Anchor( &m2an[n], stream ) ) != HB_Err_Ok )
 	goto Fail0;
       (void)FILE_Seek( cur_offset );
     }
@@ -2868,7 +2859,7 @@ static FT_Error  Load_Mark2Array( HB_Mark2Array*  m2a,
     goto Fail;
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail:
   for ( k = 0; k < m; k++ )
@@ -2918,10 +2909,10 @@ static void  Free_Mark2Array( HB_Mark2Array*  m2a,
 
 /* MarkMarkPosFormat1 */
 
-static FT_Error  Load_MarkMarkPos( HB_GPOS_SubTable* st,
+static HB_Error  Load_MarkMarkPos( HB_GPOS_SubTable* st,
 				   FT_Stream         stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_Memory memory = stream->memory;
   HB_MarkMarkPos* mmp = &st->markmark;
 
@@ -2941,7 +2932,7 @@ static FT_Error  Load_MarkMarkPos( HB_GPOS_SubTable* st,
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
        ( error = _HB_OPEN_Load_Coverage( &mmp->Mark1Coverage,
-				stream ) ) != FT_Err_Ok )
+				stream ) ) != HB_Err_Ok )
     return error;
   (void)FILE_Seek( cur_offset );
 
@@ -2955,7 +2946,7 @@ static FT_Error  Load_MarkMarkPos( HB_GPOS_SubTable* st,
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
        ( error = _HB_OPEN_Load_Coverage( &mmp->Mark2Coverage,
-				stream ) ) != FT_Err_Ok )
+				stream ) ) != HB_Err_Ok )
     goto Fail3;
   (void)FILE_Seek( cur_offset );
 
@@ -2969,7 +2960,7 @@ static FT_Error  Load_MarkMarkPos( HB_GPOS_SubTable* st,
 
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
-       ( error = Load_MarkArray( &mmp->Mark1Array, stream ) ) != FT_Err_Ok )
+       ( error = Load_MarkArray( &mmp->Mark1Array, stream ) ) != HB_Err_Ok )
     goto Fail2;
   (void)FILE_Seek( cur_offset );
 
@@ -2983,10 +2974,10 @@ static FT_Error  Load_MarkMarkPos( HB_GPOS_SubTable* st,
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
        ( error = Load_Mark2Array( &mmp->Mark2Array, mmp->ClassCount,
-				  stream ) ) != FT_Err_Ok )
+				  stream ) ) != HB_Err_Ok )
     goto Fail1;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   Free_MarkArray( &mmp->Mark1Array, memory );
@@ -3012,7 +3003,7 @@ static void  Free_MarkMarkPos( HB_GPOS_SubTable* st,
 }
 
 
-static FT_Error  Lookup_MarkMarkPos( GPOS_Instance*    gpi,
+static HB_Error  Lookup_MarkMarkPos( GPOS_Instance*    gpi,
 				     HB_GPOS_SubTable* st,
 				     HB_Buffer        buffer,
 				     FT_UShort         flags,
@@ -3022,7 +3013,7 @@ static FT_Error  Lookup_MarkMarkPos( GPOS_Instance*    gpi,
   FT_UShort        i, j, mark1_index, mark2_index, property, class;
   FT_Pos           x_mark1_value, y_mark1_value,
 		   x_mark2_value, y_mark2_value;
-  FT_Error         error;
+  HB_Error         error;
   HB_GPOSHeader*  gpos = gpi->gpos;
   HB_MarkMarkPos* mmp = &st->markmark;
 
@@ -3089,18 +3080,18 @@ static FT_Error  Lookup_MarkMarkPos( GPOS_Instance*    gpi,
   ma1 = &mmp->Mark1Array;
 
   if ( mark1_index >= ma1->MarkCount )
-    return HB_Err_Invalid_GPOS_SubTable;
+    return _hb_err(HB_Err_Invalid_GPOS_SubTable);
 
   class        = ma1->MarkRecord[mark1_index].Class;
   mark1_anchor = &ma1->MarkRecord[mark1_index].MarkAnchor;
 
   if ( class >= mmp->ClassCount )
-    return HB_Err_Invalid_GPOS_SubTable;
+    return _hb_err(HB_Err_Invalid_GPOS_SubTable);
 
   ma2 = &mmp->Mark2Array;
 
   if ( mark2_index >= ma2->Mark2Count )
-    return HB_Err_Invalid_GPOS_SubTable;
+    return _hb_err(HB_Err_Invalid_GPOS_SubTable);
 
   m2r          = &ma2->Mark2Record[mark2_index];
   mark2_anchor = &m2r->Mark2Anchor[class];
@@ -3126,7 +3117,7 @@ static FT_Error  Lookup_MarkMarkPos( GPOS_Instance*    gpi,
 
   (buffer->in_pos)++;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
@@ -3134,14 +3125,14 @@ static FT_Error  Lookup_MarkMarkPos( GPOS_Instance*    gpi,
    7 or 8).  This is only called after we've determined that the stream
    matches the subrule.                                                 */
 
-static FT_Error  Do_ContextPos( GPOS_Instance*        gpi,
+static HB_Error  Do_ContextPos( GPOS_Instance*        gpi,
 				FT_UShort             GlyphCount,
 				FT_UShort             PosCount,
 				HB_PosLookupRecord*  pos,
 				HB_Buffer            buffer,
 				int                   nesting_level )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_ULong i, old_pos;
 
 
@@ -3172,7 +3163,7 @@ static FT_Error  Do_ContextPos( GPOS_Instance*        gpi,
     }
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
@@ -3180,10 +3171,10 @@ static FT_Error  Do_ContextPos( GPOS_Instance*        gpi,
 
 /* PosRule */
 
-static FT_Error  Load_PosRule( HB_PosRule*  pr,
+static HB_Error  Load_PosRule( HB_PosRule*  pr,
 			       FT_Stream     stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_Memory memory = stream->memory;
 
   FT_UShort             n, count;
@@ -3237,7 +3228,7 @@ static FT_Error  Load_PosRule( HB_PosRule*  pr,
 
   FORGET_Frame();
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   FREE( plr );
@@ -3258,10 +3249,10 @@ static void  Free_PosRule( HB_PosRule*  pr,
 
 /* PosRuleSet */
 
-static FT_Error  Load_PosRuleSet( HB_PosRuleSet*  prs,
+static HB_Error  Load_PosRuleSet( HB_PosRuleSet*  prs,
 				  FT_Stream        stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_Memory memory = stream->memory;
 
   FT_UShort     n, m, count;
@@ -3297,12 +3288,12 @@ static FT_Error  Load_PosRuleSet( HB_PosRuleSet*  prs,
 
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
-	 ( error = Load_PosRule( &pr[n], stream ) ) != FT_Err_Ok )
+	 ( error = Load_PosRule( &pr[n], stream ) ) != HB_Err_Ok )
       goto Fail;
     (void)FILE_Seek( cur_offset );
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail:
   for ( m = 0; m < n; m++ )
@@ -3336,10 +3327,10 @@ static void  Free_PosRuleSet( HB_PosRuleSet*  prs,
 
 /* ContextPosFormat1 */
 
-static FT_Error  Load_ContextPos1( HB_ContextPosFormat1*  cpf1,
+static HB_Error  Load_ContextPos1( HB_ContextPosFormat1*  cpf1,
 				   FT_Stream               stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_Memory memory = stream->memory;
 
   FT_UShort        n, m, count;
@@ -3359,7 +3350,7 @@ static FT_Error  Load_ContextPos1( HB_ContextPosFormat1*  cpf1,
 
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
-       ( error = _HB_OPEN_Load_Coverage( &cpf1->Coverage, stream ) ) != FT_Err_Ok )
+       ( error = _HB_OPEN_Load_Coverage( &cpf1->Coverage, stream ) ) != HB_Err_Ok )
     return error;
   (void)FILE_Seek( cur_offset );
 
@@ -3388,12 +3379,12 @@ static FT_Error  Load_ContextPos1( HB_ContextPosFormat1*  cpf1,
 
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
-	 ( error = Load_PosRuleSet( &prs[n], stream ) ) != FT_Err_Ok )
+	 ( error = Load_PosRuleSet( &prs[n], stream ) ) != HB_Err_Ok )
       goto Fail1;
     (void)FILE_Seek( cur_offset );
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   for ( m = 0; m < n; m++ )
@@ -3432,11 +3423,11 @@ static void  Free_ContextPos1( HB_ContextPosFormat1*  cpf1,
 
 /* PosClassRule */
 
-static FT_Error  Load_PosClassRule( HB_ContextPosFormat2*  cpf2,
+static HB_Error  Load_PosClassRule( HB_ContextPosFormat2*  cpf2,
 				    HB_PosClassRule*       pcr,
 				    FT_Stream               stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_Memory memory = stream->memory;
 
   FT_UShort             n, count;
@@ -3503,7 +3494,7 @@ static FT_Error  Load_PosClassRule( HB_ContextPosFormat2*  cpf2,
 
   FORGET_Frame();
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   FREE( plr );
@@ -3524,11 +3515,11 @@ static void  Free_PosClassRule( HB_PosClassRule*  pcr,
 
 /* PosClassSet */
 
-static FT_Error  Load_PosClassSet( HB_ContextPosFormat2*  cpf2,
+static HB_Error  Load_PosClassSet( HB_ContextPosFormat2*  cpf2,
 				   HB_PosClassSet*        pcs,
 				   FT_Stream               stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_Memory memory = stream->memory;
 
   FT_UShort          n, m, count;
@@ -3565,12 +3556,12 @@ static FT_Error  Load_PosClassSet( HB_ContextPosFormat2*  cpf2,
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
 	 ( error = Load_PosClassRule( cpf2, &pcr[n],
-				      stream ) ) != FT_Err_Ok )
+				      stream ) ) != HB_Err_Ok )
       goto Fail;
     (void)FILE_Seek( cur_offset );
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail:
   for ( m = 0; m < n; m++ )
@@ -3604,10 +3595,10 @@ static void  Free_PosClassSet( HB_PosClassSet*  pcs,
 
 /* ContextPosFormat2 */
 
-static FT_Error  Load_ContextPos2( HB_ContextPosFormat2*  cpf2,
+static HB_Error  Load_ContextPos2( HB_ContextPosFormat2*  cpf2,
 				   FT_Stream               stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_Memory memory = stream->memory;
 
   FT_UShort         n, m, count;
@@ -3627,7 +3618,7 @@ static FT_Error  Load_ContextPos2( HB_ContextPosFormat2*  cpf2,
 
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
-       ( error = _HB_OPEN_Load_Coverage( &cpf2->Coverage, stream ) ) != FT_Err_Ok )
+       ( error = _HB_OPEN_Load_Coverage( &cpf2->Coverage, stream ) ) != HB_Err_Ok )
     return error;
   (void)FILE_Seek( cur_offset );
 
@@ -3646,7 +3637,7 @@ static FT_Error  Load_ContextPos2( HB_ContextPosFormat2*  cpf2,
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
        ( error = _HB_OPEN_Load_ClassDefinition( &cpf2->ClassDef, count,
-				       stream ) ) != FT_Err_Ok )
+				       stream ) ) != HB_Err_Ok )
     goto Fail3;
   (void)FILE_Seek( cur_offset );
 
@@ -3672,7 +3663,7 @@ static FT_Error  Load_ContextPos2( HB_ContextPosFormat2*  cpf2,
       cur_offset = FILE_Pos();
       if ( FILE_Seek( new_offset ) ||
 	   ( error = Load_PosClassSet( cpf2, &pcs[n],
-				       stream ) ) != FT_Err_Ok )
+				       stream ) ) != HB_Err_Ok )
 	goto Fail1;
       (void)FILE_Seek( cur_offset );
     }
@@ -3685,7 +3676,7 @@ static FT_Error  Load_ContextPos2( HB_ContextPosFormat2*  cpf2,
     }
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   for ( m = 0; m < n; n++ )
@@ -3728,10 +3719,10 @@ static void  Free_ContextPos2( HB_ContextPosFormat2*  cpf2,
 
 /* ContextPosFormat3 */
 
-static FT_Error  Load_ContextPos3( HB_ContextPosFormat3*  cpf3,
+static HB_Error  Load_ContextPos3( HB_ContextPosFormat3*  cpf3,
 				   FT_Stream               stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_Memory memory = stream->memory;
 
   FT_UShort             n, count;
@@ -3771,7 +3762,7 @@ static FT_Error  Load_ContextPos3( HB_ContextPosFormat3*  cpf3,
 
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
-	 ( error = _HB_OPEN_Load_Coverage( &c[n], stream ) ) != FT_Err_Ok )
+	 ( error = _HB_OPEN_Load_Coverage( &c[n], stream ) ) != HB_Err_Ok )
       goto Fail2;
     (void)FILE_Seek( cur_offset );
   }
@@ -3796,7 +3787,7 @@ static FT_Error  Load_ContextPos3( HB_ContextPosFormat3*  cpf3,
 
   FORGET_Frame();
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   FREE( plr );
@@ -3835,10 +3826,10 @@ static void  Free_ContextPos3( HB_ContextPosFormat3*  cpf3,
 
 /* ContextPos */
 
-static FT_Error  Load_ContextPos( HB_GPOS_SubTable* st,
+static HB_Error  Load_ContextPos( HB_GPOS_SubTable* st,
 				  FT_Stream        stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   HB_ContextPos*   cp = &st->context;
 
 
@@ -3861,10 +3852,10 @@ static FT_Error  Load_ContextPos( HB_GPOS_SubTable* st,
     return Load_ContextPos3( &cp->cpf.cpf3, stream );
 
   default:
-    return HB_Err_Invalid_GPOS_SubTable_Format;
+    return _hb_err(HB_Err_Invalid_GPOS_SubTable_Format);
   }
 
-  return FT_Err_Ok;               /* never reached */
+  return HB_Err_Ok;               /* never reached */
 }
 
 
@@ -3875,22 +3866,15 @@ static void  Free_ContextPos( HB_GPOS_SubTable* st,
 
   switch ( cp->PosFormat )
   {
-  case 1:
-    Free_ContextPos1( &cp->cpf.cpf1, memory );
-    break;
-
-  case 2:
-    Free_ContextPos2( &cp->cpf.cpf2, memory );
-    break;
-
-  case 3:
-    Free_ContextPos3( &cp->cpf.cpf3, memory );
-    break;
+  case 1:  Free_ContextPos1( &cp->cpf.cpf1, memory ); break;
+  case 2:  Free_ContextPos2( &cp->cpf.cpf2, memory ); break;
+  case 3:  Free_ContextPos3( &cp->cpf.cpf3, memory ); break;
+  default:					      break;
   }
 }
 
 
-static FT_Error  Lookup_ContextPos1( GPOS_Instance*          gpi,
+static HB_Error  Lookup_ContextPos1( GPOS_Instance*          gpi,
 				     HB_ContextPosFormat1*  cpf1,
 				     HB_Buffer              buffer,
 				     FT_UShort               flags,
@@ -3899,7 +3883,7 @@ static FT_Error  Lookup_ContextPos1( GPOS_Instance*          gpi,
 {
   FT_UShort        index, property;
   FT_UShort        i, j, k, numpr;
-  FT_Error         error;
+  HB_Error         error;
   HB_GPOSHeader*  gpos = gpi->gpos;
 
   HB_PosRule*     pr;
@@ -3955,7 +3939,7 @@ static FT_Error  Lookup_ContextPos1( GPOS_Instance*          gpi,
 }
 
 
-static FT_Error  Lookup_ContextPos2( GPOS_Instance*          gpi,
+static HB_Error  Lookup_ContextPos2( GPOS_Instance*          gpi,
 				     HB_ContextPosFormat2*  cpf2,
 				     HB_Buffer              buffer,
 				     FT_UShort               flags,
@@ -3963,7 +3947,7 @@ static FT_Error  Lookup_ContextPos2( GPOS_Instance*          gpi,
 				     int                     nesting_level )
 {
   FT_UShort          index, property;
-  FT_Error           error;
+  HB_Error           error;
   FT_Memory          memory = gpi->face->memory;
   FT_UShort          i, j, k, known_classes;
 
@@ -4001,7 +3985,7 @@ static FT_Error  Lookup_ContextPos2( GPOS_Instance*          gpi,
   pcs = &cpf2->PosClassSet[classes[0]];
   if ( !pcs )
   {
-    error = HB_Err_Invalid_GPOS_SubTable;
+    error = _hb_err(HB_Err_Invalid_GPOS_SubTable);
     goto End;
   }
 
@@ -4063,14 +4047,14 @@ End:
 }
 
 
-static FT_Error  Lookup_ContextPos3( GPOS_Instance*          gpi,
+static HB_Error  Lookup_ContextPos3( GPOS_Instance*          gpi,
 				     HB_ContextPosFormat3*  cpf3,
 				     HB_Buffer              buffer,
 				     FT_UShort               flags,
 				     FT_UShort               context_length,
 				     int                     nesting_level )
 {
-  FT_Error         error;
+  HB_Error         error;
   FT_UShort        index, i, j, property;
   HB_GPOSHeader*  gpos = gpi->gpos;
 
@@ -4115,7 +4099,7 @@ static FT_Error  Lookup_ContextPos3( GPOS_Instance*          gpi,
 }
 
 
-static FT_Error  Lookup_ContextPos( GPOS_Instance*    gpi,
+static HB_Error  Lookup_ContextPos( GPOS_Instance*    gpi,
 				    HB_GPOS_SubTable* st,
 				    HB_Buffer        buffer,
 				    FT_UShort         flags,
@@ -4139,10 +4123,10 @@ static FT_Error  Lookup_ContextPos( GPOS_Instance*    gpi,
 			       flags, context_length, nesting_level );
 
   default:
-    return HB_Err_Invalid_GPOS_SubTable_Format;
+    return _hb_err(HB_Err_Invalid_GPOS_SubTable_Format);
   }
 
-  return FT_Err_Ok;               /* never reached */
+  return HB_Err_Ok;               /* never reached */
 }
 
 
@@ -4150,10 +4134,10 @@ static FT_Error  Lookup_ContextPos( GPOS_Instance*    gpi,
 
 /* ChainPosRule */
 
-static FT_Error  Load_ChainPosRule( HB_ChainPosRule*  cpr,
+static HB_Error  Load_ChainPosRule( HB_ChainPosRule*  cpr,
 				    FT_Stream          stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_Memory memory = stream->memory;
 
   FT_UShort             n, count;
@@ -4263,7 +4247,7 @@ static FT_Error  Load_ChainPosRule( HB_ChainPosRule*  cpr,
 
   FORGET_Frame();
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   FREE( plr );
@@ -4292,10 +4276,10 @@ static void  Free_ChainPosRule( HB_ChainPosRule*  cpr,
 
 /* ChainPosRuleSet */
 
-static FT_Error  Load_ChainPosRuleSet( HB_ChainPosRuleSet*  cprs,
+static HB_Error  Load_ChainPosRuleSet( HB_ChainPosRuleSet*  cprs,
 				       FT_Stream             stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_Memory memory = stream->memory;
 
   FT_UShort          n, m, count;
@@ -4331,12 +4315,12 @@ static FT_Error  Load_ChainPosRuleSet( HB_ChainPosRuleSet*  cprs,
 
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
-	 ( error = Load_ChainPosRule( &cpr[n], stream ) ) != FT_Err_Ok )
+	 ( error = Load_ChainPosRule( &cpr[n], stream ) ) != HB_Err_Ok )
       goto Fail;
     (void)FILE_Seek( cur_offset );
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail:
   for ( m = 0; m < n; m++ )
@@ -4370,10 +4354,10 @@ static void  Free_ChainPosRuleSet( HB_ChainPosRuleSet*  cprs,
 
 /* ChainContextPosFormat1 */
 
-static FT_Error  Load_ChainContextPos1( HB_ChainContextPosFormat1*  ccpf1,
+static HB_Error  Load_ChainContextPos1( HB_ChainContextPosFormat1*  ccpf1,
 					FT_Stream                    stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_Memory memory = stream->memory;
 
   FT_UShort             n, m, count;
@@ -4393,7 +4377,7 @@ static FT_Error  Load_ChainContextPos1( HB_ChainContextPosFormat1*  ccpf1,
 
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
-       ( error = _HB_OPEN_Load_Coverage( &ccpf1->Coverage, stream ) ) != FT_Err_Ok )
+       ( error = _HB_OPEN_Load_Coverage( &ccpf1->Coverage, stream ) ) != HB_Err_Ok )
     return error;
   (void)FILE_Seek( cur_offset );
 
@@ -4422,12 +4406,12 @@ static FT_Error  Load_ChainContextPos1( HB_ChainContextPosFormat1*  ccpf1,
 
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
-	 ( error = Load_ChainPosRuleSet( &cprs[n], stream ) ) != FT_Err_Ok )
+	 ( error = Load_ChainPosRuleSet( &cprs[n], stream ) ) != HB_Err_Ok )
       goto Fail1;
     (void)FILE_Seek( cur_offset );
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   for ( m = 0; m < n; m++ )
@@ -4466,12 +4450,12 @@ static void  Free_ChainContextPos1( HB_ChainContextPosFormat1*  ccpf1,
 
 /* ChainPosClassRule */
 
-static FT_Error  Load_ChainPosClassRule(
+static HB_Error  Load_ChainPosClassRule(
 		   HB_ChainContextPosFormat2*  ccpf2,
 		   HB_ChainPosClassRule*       cpcr,
 		   FT_Stream                    stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_Memory memory = stream->memory;
 
   FT_UShort             n, count;
@@ -4612,7 +4596,7 @@ static FT_Error  Load_ChainPosClassRule(
 
   FORGET_Frame();
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   FREE( plr );
@@ -4641,12 +4625,12 @@ static void  Free_ChainPosClassRule( HB_ChainPosClassRule*  cpcr,
 
 /* PosClassSet */
 
-static FT_Error  Load_ChainPosClassSet(
+static HB_Error  Load_ChainPosClassSet(
 		   HB_ChainContextPosFormat2*  ccpf2,
 		   HB_ChainPosClassSet*        cpcs,
 		   FT_Stream                    stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_Memory memory = stream->memory;
 
   FT_UShort               n, m, count;
@@ -4684,12 +4668,12 @@ static FT_Error  Load_ChainPosClassSet(
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
 	 ( error = Load_ChainPosClassRule( ccpf2, &cpcr[n],
-					   stream ) ) != FT_Err_Ok )
+					   stream ) ) != HB_Err_Ok )
       goto Fail;
     (void)FILE_Seek( cur_offset );
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail:
   for ( m = 0; m < n; m++ )
@@ -4721,13 +4705,13 @@ static void  Free_ChainPosClassSet( HB_ChainPosClassSet*  cpcs,
 }
 
 
-static FT_Error GPOS_Load_EmptyOrClassDefinition( HB_ClassDefinition*  cd,
+static HB_Error GPOS_Load_EmptyOrClassDefinition( HB_ClassDefinition*  cd,
 					     FT_UShort             limit,
 					     FT_ULong              class_offset,
 					     FT_ULong              base_offset,
 					     FT_Stream             stream )
 {
-  FT_Error error;
+  HB_Error error;
   FT_ULong               cur_offset;
 
   cur_offset = FILE_Pos();
@@ -4740,7 +4724,7 @@ static FT_Error GPOS_Load_EmptyOrClassDefinition( HB_ClassDefinition*  cd,
   else
      error = _HB_OPEN_Load_EmptyClassDefinition ( cd, stream );
 
-  if (error == FT_Err_Ok)
+  if (error == HB_Err_Ok)
     (void)FILE_Seek( cur_offset ); /* Changes error as a side-effect */
 
   return error;
@@ -4748,10 +4732,10 @@ static FT_Error GPOS_Load_EmptyOrClassDefinition( HB_ClassDefinition*  cd,
 
 /* ChainContextPosFormat2 */
 
-static FT_Error  Load_ChainContextPos2( HB_ChainContextPosFormat2*  ccpf2,
+static HB_Error  Load_ChainContextPos2( HB_ChainContextPosFormat2*  ccpf2,
 					FT_Stream                    stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_Memory memory = stream->memory;
 
   FT_UShort              n, m, count;
@@ -4772,7 +4756,7 @@ static FT_Error  Load_ChainContextPos2( HB_ChainContextPosFormat2*  ccpf2,
 
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
-       ( error = _HB_OPEN_Load_Coverage( &ccpf2->Coverage, stream ) ) != FT_Err_Ok )
+       ( error = _HB_OPEN_Load_Coverage( &ccpf2->Coverage, stream ) ) != HB_Err_Ok )
     return error;
   (void)FILE_Seek( cur_offset );
 
@@ -4793,15 +4777,15 @@ static FT_Error  Load_ChainContextPos2( HB_ChainContextPosFormat2*  ccpf2,
 
   if ( ( error = GPOS_Load_EmptyOrClassDefinition( &ccpf2->BacktrackClassDef, 65535,
 					      backtrack_offset, base_offset,
-					      stream ) ) != FT_Err_Ok )
+					      stream ) ) != HB_Err_Ok )
     goto Fail5;
   if ( ( error = GPOS_Load_EmptyOrClassDefinition( &ccpf2->InputClassDef, count,
 					      input_offset, base_offset,
-					      stream ) ) != FT_Err_Ok )
+					      stream ) ) != HB_Err_Ok )
     goto Fail4;
   if ( ( error = GPOS_Load_EmptyOrClassDefinition( &ccpf2->LookaheadClassDef, 65535,
 					      lookahead_offset, base_offset,
-					      stream ) ) != FT_Err_Ok )
+					      stream ) ) != HB_Err_Ok )
     goto Fail3;
 
   ccpf2->ChainPosClassSet   = NULL;
@@ -4828,7 +4812,7 @@ static FT_Error  Load_ChainContextPos2( HB_ChainContextPosFormat2*  ccpf2,
       cur_offset = FILE_Pos();
       if ( FILE_Seek( new_offset ) ||
 	   ( error = Load_ChainPosClassSet( ccpf2, &cpcs[n],
-					    stream ) ) != FT_Err_Ok )
+					    stream ) ) != HB_Err_Ok )
 	goto Fail1;
       (void)FILE_Seek( cur_offset );
     }
@@ -4841,7 +4825,7 @@ static FT_Error  Load_ChainContextPos2( HB_ChainContextPosFormat2*  ccpf2,
     }
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   for ( m = 0; m < n; m++ )
@@ -4893,10 +4877,10 @@ static void  Free_ChainContextPos2( HB_ChainContextPosFormat2*  ccpf2,
 
 /* ChainContextPosFormat3 */
 
-static FT_Error  Load_ChainContextPos3( HB_ChainContextPosFormat3*  ccpf3,
+static HB_Error  Load_ChainContextPos3( HB_ChainContextPosFormat3*  ccpf3,
 					FT_Stream                    stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_Memory memory = stream->memory;
 
   FT_UShort             n, nb, ni, nl, m, count;
@@ -4939,7 +4923,7 @@ static FT_Error  Load_ChainContextPos3( HB_ChainContextPosFormat3*  ccpf3,
 
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
-	 ( error = _HB_OPEN_Load_Coverage( &b[nb], stream ) ) != FT_Err_Ok )
+	 ( error = _HB_OPEN_Load_Coverage( &b[nb], stream ) ) != HB_Err_Ok )
       goto Fail4;
     (void)FILE_Seek( cur_offset );
   }
@@ -4971,7 +4955,7 @@ static FT_Error  Load_ChainContextPos3( HB_ChainContextPosFormat3*  ccpf3,
 
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
-	 ( error = _HB_OPEN_Load_Coverage( &i[ni], stream ) ) != FT_Err_Ok )
+	 ( error = _HB_OPEN_Load_Coverage( &i[ni], stream ) ) != HB_Err_Ok )
       goto Fail3;
     (void)FILE_Seek( cur_offset );
   }
@@ -5004,7 +4988,7 @@ static FT_Error  Load_ChainContextPos3( HB_ChainContextPosFormat3*  ccpf3,
 
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
-	 ( error = _HB_OPEN_Load_Coverage( &l[nl], stream ) ) != FT_Err_Ok )
+	 ( error = _HB_OPEN_Load_Coverage( &l[nl], stream ) ) != HB_Err_Ok )
       goto Fail2;
     (void)FILE_Seek( cur_offset );
   }
@@ -5036,7 +5020,7 @@ static FT_Error  Load_ChainContextPos3( HB_ChainContextPosFormat3*  ccpf3,
 
   FORGET_Frame();
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   FREE( plr );
@@ -5109,10 +5093,10 @@ static void  Free_ChainContextPos3( HB_ChainContextPosFormat3*  ccpf3,
 
 /* ChainContextPos */
 
-static FT_Error  Load_ChainContextPos( HB_GPOS_SubTable* st,
+static HB_Error  Load_ChainContextPos( HB_GPOS_SubTable* st,
 				       FT_Stream             stream )
 {
-  FT_Error  error;
+  HB_Error  error;
   HB_ChainContextPos*  ccp = &st->chain;
 
 
@@ -5135,10 +5119,10 @@ static FT_Error  Load_ChainContextPos( HB_GPOS_SubTable* st,
     return Load_ChainContextPos3( &ccp->ccpf.ccpf3, stream );
 
   default:
-    return HB_Err_Invalid_GPOS_SubTable_Format;
+    return _hb_err(HB_Err_Invalid_GPOS_SubTable_Format);
   }
 
-  return FT_Err_Ok;               /* never reached */
+  return HB_Err_Ok;               /* never reached */
 }
 
 
@@ -5149,22 +5133,15 @@ static void  Free_ChainContextPos( HB_GPOS_SubTable* st,
 
   switch ( ccp->PosFormat )
   {
-  case 1:
-    Free_ChainContextPos1( &ccp->ccpf.ccpf1, memory );
-    break;
-
-  case 2:
-    Free_ChainContextPos2( &ccp->ccpf.ccpf2, memory );
-    break;
-
-  case 3:
-    Free_ChainContextPos3( &ccp->ccpf.ccpf3, memory );
-    break;
+  case 1:  Free_ChainContextPos1( &ccp->ccpf.ccpf1, memory ); break;
+  case 2:  Free_ChainContextPos2( &ccp->ccpf.ccpf2, memory ); break;
+  case 3:  Free_ChainContextPos3( &ccp->ccpf.ccpf3, memory ); break;
+  default:						      break;
   }
 }
 
 
-static FT_Error  Lookup_ChainContextPos1(
+static HB_Error  Lookup_ChainContextPos1(
 		   GPOS_Instance*               gpi,
 		   HB_ChainContextPosFormat1*  ccpf1,
 		   HB_Buffer                   buffer,
@@ -5175,7 +5152,7 @@ static FT_Error  Lookup_ChainContextPos1(
   FT_UShort          index, property;
   FT_UShort          i, j, k, num_cpr;
   FT_UShort          bgc, igc, lgc;
-  FT_Error           error;
+  HB_Error           error;
   HB_GPOSHeader*    gpos = gpi->gpos;
 
   HB_ChainPosRule*  cpr;
@@ -5293,7 +5270,7 @@ static FT_Error  Lookup_ChainContextPos1(
 }
 
 
-static FT_Error  Lookup_ChainContextPos2(
+static HB_Error  Lookup_ChainContextPos2(
 		   GPOS_Instance*               gpi,
 		   HB_ChainContextPosFormat2*  ccpf2,
 		   HB_Buffer                   buffer,
@@ -5303,7 +5280,7 @@ static FT_Error  Lookup_ChainContextPos2(
 {
   FT_UShort              index, property;
   FT_Memory              memory = gpi->face->memory;
-  FT_Error               error;
+  HB_Error               error;
   FT_UShort              i, j, k;
   FT_UShort              bgc, igc, lgc;
   FT_UShort              known_backtrack_classes,
@@ -5357,7 +5334,7 @@ static FT_Error  Lookup_ChainContextPos2(
   cpcs = &ccpf2->ChainPosClassSet[input_classes[0]];
   if ( !cpcs )
   {
-    error = HB_Err_Invalid_GPOS_SubTable;
+    error = _hb_err(HB_Err_Invalid_GPOS_SubTable);
     goto End1;
   }
 
@@ -5496,7 +5473,7 @@ End3:
 }
 
 
-static FT_Error  Lookup_ChainContextPos3(
+static HB_Error  Lookup_ChainContextPos3(
 		   GPOS_Instance*               gpi,
 		   HB_ChainContextPosFormat3*  ccpf3,
 		   HB_Buffer                   buffer,
@@ -5506,7 +5483,7 @@ static FT_Error  Lookup_ChainContextPos3(
 {
   FT_UShort        index, i, j, property;
   FT_UShort        bgc, igc, lgc;
-  FT_Error         error;
+  HB_Error         error;
   HB_GPOSHeader*  gpos = gpi->gpos;
 
   HB_Coverage*    bc;
@@ -5607,7 +5584,7 @@ static FT_Error  Lookup_ChainContextPos3(
 }
 
 
-static FT_Error  Lookup_ChainContextPos(
+static HB_Error  Lookup_ChainContextPos(
 		   GPOS_Instance*        gpi,
 		   HB_GPOS_SubTable* st,
 		   HB_Buffer            buffer,
@@ -5635,10 +5612,10 @@ static FT_Error  Lookup_ChainContextPos(
 				    nesting_level );
 
   default:
-    return HB_Err_Invalid_GPOS_SubTable_Format;
+    return _hb_err(HB_Err_Invalid_GPOS_SubTable_Format);
   }
 
-  return FT_Err_Ok;               /* never reached */
+  return HB_Err_Ok;               /* never reached */
 }
 
 
@@ -5649,7 +5626,7 @@ static FT_Error  Lookup_ChainContextPos(
 
 
 
-FT_Error  HB_GPOS_Select_Script( HB_GPOSHeader*  gpos,
+HB_Error  HB_GPOS_Select_Script( HB_GPOSHeader*  gpos,
 				 FT_ULong         script_tag,
 				 FT_UShort*       script_index )
 {
@@ -5660,7 +5637,7 @@ FT_Error  HB_GPOS_Select_Script( HB_GPOSHeader*  gpos,
 
 
   if ( !gpos || !script_index )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   sl = &gpos->ScriptList;
   sr = sl->ScriptRecord;
@@ -5670,7 +5647,7 @@ FT_Error  HB_GPOS_Select_Script( HB_GPOSHeader*  gpos,
     {
       *script_index = n;
 
-      return FT_Err_Ok;
+      return HB_Err_Ok;
     }
 
   return HB_Err_Not_Covered;
@@ -5678,7 +5655,7 @@ FT_Error  HB_GPOS_Select_Script( HB_GPOSHeader*  gpos,
 
 
 
-FT_Error  HB_GPOS_Select_Language( HB_GPOSHeader*  gpos,
+HB_Error  HB_GPOS_Select_Language( HB_GPOSHeader*  gpos,
 				   FT_ULong         language_tag,
 				   FT_UShort        script_index,
 				   FT_UShort*       language_index,
@@ -5693,13 +5670,13 @@ FT_Error  HB_GPOS_Select_Language( HB_GPOSHeader*  gpos,
 
 
   if ( !gpos || !language_index || !req_feature_index )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   sl = &gpos->ScriptList;
   sr = sl->ScriptRecord;
 
   if ( script_index >= sl->ScriptCount )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   s   = &sr[script_index].Script;
   lsr = s->LangSysRecord;
@@ -5710,7 +5687,7 @@ FT_Error  HB_GPOS_Select_Language( HB_GPOSHeader*  gpos,
       *language_index = n;
       *req_feature_index = lsr[n].LangSys.ReqFeatureIndex;
 
-      return FT_Err_Ok;
+      return HB_Err_Ok;
     }
 
   return HB_Err_Not_Covered;
@@ -5721,7 +5698,7 @@ FT_Error  HB_GPOS_Select_Language( HB_GPOSHeader*  gpos,
    default language (DefaultLangSys)                              */
 
 
-FT_Error  HB_GPOS_Select_Feature( HB_GPOSHeader*  gpos,
+HB_Error  HB_GPOS_Select_Feature( HB_GPOSHeader*  gpos,
 				  FT_ULong         feature_tag,
 				  FT_UShort        script_index,
 				  FT_UShort        language_index,
@@ -5741,7 +5718,7 @@ FT_Error  HB_GPOS_Select_Feature( HB_GPOSHeader*  gpos,
 
 
   if ( !gpos || !feature_index )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   sl = &gpos->ScriptList;
   sr = sl->ScriptRecord;
@@ -5750,7 +5727,7 @@ FT_Error  HB_GPOS_Select_Feature( HB_GPOSHeader*  gpos,
   fr = fl->FeatureRecord;
 
   if ( script_index >= sl->ScriptCount )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   s   = &sr[script_index].Script;
   lsr = s->LangSysRecord;
@@ -5760,7 +5737,7 @@ FT_Error  HB_GPOS_Select_Feature( HB_GPOSHeader*  gpos,
   else
   {
     if ( language_index >= s->LangSysCount )
-      return FT_Err_Invalid_Argument;
+      return HB_Err_Invalid_Argument;
 
     ls = &lsr[language_index].LangSys;
   }
@@ -5770,13 +5747,13 @@ FT_Error  HB_GPOS_Select_Feature( HB_GPOSHeader*  gpos,
   for ( n = 0; n < ls->FeatureCount; n++ )
   {
     if ( fi[n] >= fl->FeatureCount )
-      return HB_Err_Invalid_GPOS_SubTable_Format;
+      return _hb_err(HB_Err_Invalid_GPOS_SubTable_Format);
 
     if ( feature_tag == fr[fi[n]].FeatureTag )
     {
       *feature_index = fi[n];
 
-      return FT_Err_Ok;
+      return HB_Err_Ok;
     }
   }
 
@@ -5787,10 +5764,10 @@ FT_Error  HB_GPOS_Select_Feature( HB_GPOSHeader*  gpos,
 /* The next three functions return a null-terminated list */
 
 
-FT_Error  HB_GPOS_Query_Scripts( HB_GPOSHeader*  gpos,
+HB_Error  HB_GPOS_Query_Scripts( HB_GPOSHeader*  gpos,
 				 FT_ULong**       script_tag_list )
 {
-  FT_Error           error;
+  HB_Error           error;
   FT_Memory          memory;
   FT_UShort          n;
   FT_ULong*          stl;
@@ -5800,7 +5777,7 @@ FT_Error  HB_GPOS_Query_Scripts( HB_GPOSHeader*  gpos,
 
 
   if ( !gpos || !script_tag_list )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   memory = gpos->memory;
   sl = &gpos->ScriptList;
@@ -5815,16 +5792,16 @@ FT_Error  HB_GPOS_Query_Scripts( HB_GPOSHeader*  gpos,
 
   *script_tag_list = stl;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
 
-FT_Error  HB_GPOS_Query_Languages( HB_GPOSHeader*  gpos,
+HB_Error  HB_GPOS_Query_Languages( HB_GPOSHeader*  gpos,
 				   FT_UShort        script_index,
 				   FT_ULong**       language_tag_list )
 {
-  FT_Error            error;
+  HB_Error            error;
   FT_Memory           memory;
   FT_UShort           n;
   FT_ULong*           ltl;
@@ -5836,14 +5813,14 @@ FT_Error  HB_GPOS_Query_Languages( HB_GPOSHeader*  gpos,
 
 
   if ( !gpos || !language_tag_list )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   memory = gpos->memory;
   sl = &gpos->ScriptList;
   sr = sl->ScriptRecord;
 
   if ( script_index >= sl->ScriptCount )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   s   = &sr[script_index].Script;
   lsr = s->LangSysRecord;
@@ -5857,7 +5834,7 @@ FT_Error  HB_GPOS_Query_Languages( HB_GPOSHeader*  gpos,
 
   *language_tag_list = ltl;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
@@ -5865,13 +5842,13 @@ FT_Error  HB_GPOS_Query_Languages( HB_GPOSHeader*  gpos,
    default language (DefaultLangSys)                              */
 
 
-FT_Error  HB_GPOS_Query_Features( HB_GPOSHeader*  gpos,
+HB_Error  HB_GPOS_Query_Features( HB_GPOSHeader*  gpos,
 				  FT_UShort        script_index,
 				  FT_UShort        language_index,
 				  FT_ULong**       feature_tag_list )
 {
   FT_UShort           n;
-  FT_Error            error;
+  HB_Error            error;
   FT_Memory           memory;
   FT_ULong*           ftl;
 
@@ -5887,7 +5864,7 @@ FT_Error  HB_GPOS_Query_Features( HB_GPOSHeader*  gpos,
 
 
   if ( !gpos || !feature_tag_list )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   memory = gpos->memory;
   sl = &gpos->ScriptList;
@@ -5897,7 +5874,7 @@ FT_Error  HB_GPOS_Query_Features( HB_GPOSHeader*  gpos,
   fr = fl->FeatureRecord;
 
   if ( script_index >= sl->ScriptCount )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   s   = &sr[script_index].Script;
   lsr = s->LangSysRecord;
@@ -5907,7 +5884,7 @@ FT_Error  HB_GPOS_Query_Features( HB_GPOSHeader*  gpos,
   else
   {
     if ( language_index >= s->LangSysCount )
-      return FT_Err_Invalid_Argument;
+      return HB_Err_Invalid_Argument;
 
     ls = &lsr[language_index].LangSys;
   }
@@ -5922,7 +5899,7 @@ FT_Error  HB_GPOS_Query_Features( HB_GPOSHeader*  gpos,
     if ( fi[n] >= fl->FeatureCount )
     {
       FREE( ftl );
-      return HB_Err_Invalid_GPOS_SubTable_Format;
+      return _hb_err(HB_Err_Invalid_GPOS_SubTable_Format);
     }
     ftl[n] = fr[fi[n]].FeatureTag;
   }
@@ -5930,49 +5907,29 @@ FT_Error  HB_GPOS_Query_Features( HB_GPOSHeader*  gpos,
 
   *feature_tag_list = ftl;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
-typedef FT_Error  (*Lookup_Pos_Func_Type)  ( GPOS_Instance*    gpi,
-					     HB_GPOS_SubTable* st,
-					     HB_Buffer        buffer,
-					     FT_UShort         flags,
-					     FT_UShort         context_length,
-					     int               nesting_level );
-static const Lookup_Pos_Func_Type Lookup_Pos_Call_Table[] = {
-  Lookup_DefaultPos,
-  Lookup_SinglePos,		/* HB_GPOS_LOOKUP_SINGLE     1 */
-  Lookup_PairPos,		/* HB_GPOS_LOOKUP_PAIR       2 */
-  Lookup_CursivePos,		/* HB_GPOS_LOOKUP_CURSIVE    3 */
-  Lookup_MarkBasePos,		/* HB_GPOS_LOOKUP_MARKBASE   4 */
-  Lookup_MarkLigPos,		/* HB_GPOS_LOOKUP_MARKLIG    5 */
-  Lookup_MarkMarkPos,		/* HB_GPOS_LOOKUP_MARKMARK   6 */
-  Lookup_ContextPos,		/* HB_GPOS_LOOKUP_CONTEXT    7 */
-  Lookup_ChainContextPos,	/* HB_GPOS_LOOKUP_CHAIN      8 */
-  Lookup_DefaultPos,		/* HB_GPOS_LOOKUP_EXTENSION  9 */
-};
-
-/* Do an individual subtable lookup.  Returns FT_Err_Ok if positioning
+/* Do an individual subtable lookup.  Returns HB_Err_Ok if positioning
    has been done, or HB_Err_Not_Covered if not.                        */
-static FT_Error  GPOS_Do_Glyph_Lookup( GPOS_Instance*    gpi,
+static HB_Error  GPOS_Do_Glyph_Lookup( GPOS_Instance*    gpi,
 				       FT_UShort         lookup_index,
 				       HB_Buffer        buffer,
 				       FT_UShort         context_length,
 				       int               nesting_level )
 {
-  FT_Error             error = HB_Err_Not_Covered;
+  HB_Error             error = HB_Err_Not_Covered;
   FT_UShort            i, flags, lookup_count;
   HB_GPOSHeader*       gpos = gpi->gpos;
   HB_Lookup*           lo;
   int		       lookup_type;
-  Lookup_Pos_Func_Type Func;
 
 
   nesting_level++;
 
   if ( nesting_level > HB_MAX_NESTING_LEVEL )
-    return HB_Err_Too_Many_Nested_Contexts;
+    return _hb_err(HB_Err_Too_Many_Nested_Contexts);
 
   lookup_count = gpos->LookupList.LookupCount;
   if (lookup_index >= lookup_count)
@@ -5981,21 +5938,36 @@ static FT_Error  GPOS_Do_Glyph_Lookup( GPOS_Instance*    gpi,
   lo    = &gpos->LookupList.Lookup[lookup_index];
   flags = lo->LookupFlag;
   lookup_type = lo->LookupType;
-  if (lookup_type >= ARRAY_LEN (Lookup_Pos_Call_Table))
-    lookup_type = 0;
-  Func = Lookup_Pos_Call_Table[lookup_type];
 
   for ( i = 0; i < lo->SubTableCount; i++ )
   {
-    error = Func ( gpi,
-		   &lo->SubTable[i].st.gpos,
-		   buffer,
-		   flags, context_length,
-		   nesting_level );
+    HB_GPOS_SubTable *st = &lo->SubTable[i].st.gpos;
+
+    switch (lookup_type) {
+      case HB_GPOS_LOOKUP_SINGLE:
+        error = Lookup_SinglePos	( gpi, st, buffer, flags, context_length, nesting_level ); break;
+      case HB_GPOS_LOOKUP_PAIR:
+	error = Lookup_PairPos		( gpi, st, buffer, flags, context_length, nesting_level ); break;
+      case HB_GPOS_LOOKUP_CURSIVE:
+	error = Lookup_CursivePos	( gpi, st, buffer, flags, context_length, nesting_level ); break;
+      case HB_GPOS_LOOKUP_MARKBASE:
+	error = Lookup_MarkBasePos	( gpi, st, buffer, flags, context_length, nesting_level ); break;
+      case HB_GPOS_LOOKUP_MARKLIG:
+	error = Lookup_MarkLigPos	( gpi, st, buffer, flags, context_length, nesting_level ); break;
+      case HB_GPOS_LOOKUP_MARKMARK:
+	error = Lookup_MarkMarkPos	( gpi, st, buffer, flags, context_length, nesting_level ); break;
+      case HB_GPOS_LOOKUP_CONTEXT:
+	error = Lookup_ContextPos	( gpi, st, buffer, flags, context_length, nesting_level ); break;
+      case HB_GPOS_LOOKUP_CHAIN:
+	error = Lookup_ChainContextPos	( gpi, st, buffer, flags, context_length, nesting_level ); break;
+    /*case HB_GPOS_LOOKUP_EXTENSION:
+	error = Lookup_ExtensionPos	( gpi, st, buffer, flags, context_length, nesting_level ); break;*/
+      default:
+	error = HB_Err_Not_Covered;
+    }
 
     /* Check whether we have a successful positioning or an error other
        than HB_Err_Not_Covered                                         */
-
     if ( error != HB_Err_Not_Covered )
       return error;
   }
@@ -6004,106 +5976,67 @@ static FT_Error  GPOS_Do_Glyph_Lookup( GPOS_Instance*    gpi,
 }
 
 
-static FT_Error  Load_DefaultPos( HB_GPOS_SubTable* st,
-				  FT_Stream         stream )
-{
-  FT_UNUSED(st);
-  FT_UNUSED(stream);
-  return HB_Err_Invalid_GPOS_SubTable_Format;
-}
-
-typedef FT_Error  (*Load_Pos_Func_Type)( HB_GPOS_SubTable* st,
-					 FT_Stream         stream );
-static const Load_Pos_Func_Type Load_Pos_Call_Table[] = {
-  Load_DefaultPos,
-  Load_SinglePos,		/* HB_GPOS_LOOKUP_SINGLE     1 */
-  Load_PairPos,			/* HB_GPOS_LOOKUP_PAIR       2 */
-  Load_CursivePos,		/* HB_GPOS_LOOKUP_CURSIVE    3 */
-  Load_MarkBasePos,		/* HB_GPOS_LOOKUP_MARKBASE   4 */
-  Load_MarkLigPos,		/* HB_GPOS_LOOKUP_MARKLIG    5 */
-  Load_MarkMarkPos,		/* HB_GPOS_LOOKUP_MARKMARK   6 */
-  Load_ContextPos,		/* HB_GPOS_LOOKUP_CONTEXT    7 */
-  Load_ChainContextPos,		/* HB_GPOS_LOOKUP_CHAIN      8 */
-  Load_DefaultPos,		/* HB_GPOS_LOOKUP_EXTENSION  9 */
-};
-
-FT_Error  _HB_GPOS_Load_SubTable( HB_GPOS_SubTable*  st,
+HB_Error  _HB_GPOS_Load_SubTable( HB_GPOS_SubTable*  st,
 				  FT_Stream     stream,
 				  FT_UShort     lookup_type )
 {
-  Load_Pos_Func_Type Func;
-
-  if (lookup_type >= ARRAY_LEN (Load_Pos_Call_Table))
-    lookup_type = 0;
-
-  Func = Load_Pos_Call_Table[lookup_type];
-
-  return Func ( st, stream );
-}
-
-
-static void  Free_DefaultPos( HB_GPOS_SubTable* st,
-			      FT_Memory         memory )
-{
-  FT_UNUSED(st);
-  FT_UNUSED(memory);
+  switch ( lookup_type ) {
+    case HB_GPOS_LOOKUP_SINGLE:		return Load_SinglePos		( st, stream );
+    case HB_GPOS_LOOKUP_PAIR:		return Load_PairPos		( st, stream );
+    case HB_GPOS_LOOKUP_CURSIVE:	return Load_CursivePos		( st, stream );
+    case HB_GPOS_LOOKUP_MARKBASE:	return Load_MarkBasePos		( st, stream );
+    case HB_GPOS_LOOKUP_MARKLIG:	return Load_MarkLigPos		( st, stream );
+    case HB_GPOS_LOOKUP_MARKMARK:	return Load_MarkMarkPos		( st, stream );
+    case HB_GPOS_LOOKUP_CONTEXT:	return Load_ContextPos		( st, stream );
+    case HB_GPOS_LOOKUP_CHAIN:		return Load_ChainContextPos	( st, stream );
+  /*case HB_GPOS_LOOKUP_EXTENSION:	return Load_ExtensionPos	( st, stream );*/
+    default:				return _hb_err(HB_Err_Invalid_GPOS_SubTable_Format);
+  }
 }
 
-typedef void (*Free_Pos_Func_Type)( HB_GPOS_SubTable* st,
-				    FT_Memory         memory );
-static const Free_Pos_Func_Type Free_Pos_Call_Table[] = {
-  Free_DefaultPos,
-  Free_SinglePos,		/* HB_GPOS_LOOKUP_SINGLE     1 */
-  Free_PairPos,			/* HB_GPOS_LOOKUP_PAIR       2 */
-  Free_CursivePos,		/* HB_GPOS_LOOKUP_CURSIVE    3 */
-  Free_MarkBasePos,		/* HB_GPOS_LOOKUP_MARKBASE   4 */
-  Free_MarkLigPos,		/* HB_GPOS_LOOKUP_MARKLIG    5 */
-  Free_MarkMarkPos,		/* HB_GPOS_LOOKUP_MARKMARK   6 */
-  Free_ContextPos,		/* HB_GPOS_LOOKUP_CONTEXT    7 */
-  Free_ChainContextPos,		/* HB_GPOS_LOOKUP_CHAIN      8 */
-  Free_DefaultPos,		/* HB_GPOS_LOOKUP_EXTENSION  9 */
-};
 
 void  _HB_GPOS_Free_SubTable( HB_GPOS_SubTable*  st,
 			      FT_Memory     memory,
 			      FT_UShort     lookup_type )
 {
-  Free_Pos_Func_Type Func;
-
-  if (lookup_type >= ARRAY_LEN (Free_Pos_Call_Table))
-    lookup_type = 0;
-
-  Func = Free_Pos_Call_Table[lookup_type];
-
-  Func ( st, memory );
+  switch ( lookup_type ) {
+    case HB_GPOS_LOOKUP_SINGLE:		Free_SinglePos		( st, memory ); return;
+    case HB_GPOS_LOOKUP_PAIR:		Free_PairPos		( st, memory ); return;
+    case HB_GPOS_LOOKUP_CURSIVE:	Free_CursivePos		( st, memory ); return;
+    case HB_GPOS_LOOKUP_MARKBASE:	Free_MarkBasePos	( st, memory ); return;
+    case HB_GPOS_LOOKUP_MARKLIG:	Free_MarkLigPos		( st, memory ); return;
+    case HB_GPOS_LOOKUP_MARKMARK:	Free_MarkMarkPos	( st, memory ); return;
+    case HB_GPOS_LOOKUP_CONTEXT:	Free_ContextPos		( st, memory ); return;
+    case HB_GPOS_LOOKUP_CHAIN:		Free_ChainContextPos	( st, memory ); return;
+  /*case HB_GPOS_LOOKUP_EXTENSION:	Free_ExtensionPos	( st, memory ); return;*/
+    default:									return;
+  }
 }
 
 
-
 /* apply one lookup to the input string object */
 
-static FT_Error  GPOS_Do_String_Lookup( GPOS_Instance*    gpi,
+static HB_Error  GPOS_Do_String_Lookup( GPOS_Instance*    gpi,
 				   FT_UShort         lookup_index,
 				   HB_Buffer        buffer )
 {
-  FT_Error         error, retError = HB_Err_Not_Covered;
+  HB_Error         error, retError = HB_Err_Not_Covered;
   HB_GPOSHeader*  gpos = gpi->gpos;
 
   FT_UInt*  properties = gpos->LookupList.Properties;
 
-  int       nesting_level = 0;
+  const int       nesting_level = 0;
+  /* 0xFFFF indicates that we don't have a context length yet */
+  const FT_UShort context_length = 0xFFFF;
 
 
   gpi->last  = 0xFFFF;     /* no last valid glyph for cursive pos. */
 
   buffer->in_pos = 0;
-
   while ( buffer->in_pos < buffer->in_length )
   {
     if ( ~IN_PROPERTIES( buffer->in_pos ) & properties[lookup_index] )
     {
-      /* 0xFFFF indicates that we don't have a context length yet. */
-
       /* Note that the connection between mark and base glyphs hold
 	 exactly one (string) lookup.  For example, it would be possible
 	 that in the first lookup, mark glyph X is attached to base
@@ -6111,8 +6044,7 @@ static FT_Error  GPOS_Do_String_Lookup( GPOS_Instance*    gpi,
 	 It is up to the font designer to provide meaningful lookups and
 	 lookup order.                                                   */
 
-      error = GPOS_Do_Glyph_Lookup( gpi, lookup_index, buffer,
-				    0xFFFF, nesting_level );
+      error = GPOS_Do_Glyph_Lookup( gpi, lookup_index, buffer, context_length, nesting_level );
       if ( error && error != HB_Err_Not_Covered )
 	return error;
     }
@@ -6135,7 +6067,7 @@ static FT_Error  GPOS_Do_String_Lookup( GPOS_Instance*    gpi,
 }
 
 
-static FT_Error  Position_CursiveChain ( HB_Buffer     buffer )
+static HB_Error  Position_CursiveChain ( HB_Buffer     buffer )
 {
   FT_ULong   i, j;
   HB_Position positions = buffer->positions;
@@ -6156,11 +6088,11 @@ static FT_Error  Position_CursiveChain ( HB_Buffer     buffer )
       positions[j].y_pos += positions[j - positions[j].cursive_chain].y_pos;
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
-FT_Error  HB_GPOS_Add_Feature( HB_GPOSHeader*  gpos,
+HB_Error  HB_GPOS_Add_Feature( HB_GPOSHeader*  gpos,
 			       FT_UShort        feature_index,
 			       FT_UInt          property )
 {
@@ -6176,7 +6108,7 @@ FT_Error  HB_GPOS_Add_Feature( HB_GPOSHeader*  gpos,
   if ( !gpos ||
        feature_index >= gpos->FeatureList.FeatureCount ||
        gpos->FeatureList.ApplyCount == gpos->FeatureList.FeatureCount )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   gpos->FeatureList.ApplyOrder[gpos->FeatureList.ApplyCount++] = feature_index;
 
@@ -6193,12 +6125,12 @@ FT_Error  HB_GPOS_Add_Feature( HB_GPOSHeader*  gpos,
       properties[lookup_index] |= property;
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
 
-FT_Error  HB_GPOS_Clear_Features( HB_GPOSHeader*  gpos )
+HB_Error  HB_GPOS_Clear_Features( HB_GPOSHeader*  gpos )
 {
   FT_UShort i;
 
@@ -6206,7 +6138,7 @@ FT_Error  HB_GPOS_Clear_Features( HB_GPOSHeader*  gpos )
 
 
   if ( !gpos )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   gpos->FeatureList.ApplyCount = 0;
 
@@ -6215,56 +6147,57 @@ FT_Error  HB_GPOS_Clear_Features( HB_GPOSHeader*  gpos )
   for ( i = 0; i < gpos->LookupList.LookupCount; i++ )
     properties[i] = 0;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
 
-FT_Error  HB_GPOS_Register_Glyph_Function( HB_GPOSHeader*    gpos,
+HB_Error  HB_GPOS_Register_Glyph_Function( HB_GPOSHeader*    gpos,
 					   HB_GlyphFunction  gfunc )
 {
   if ( !gpos )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   gpos->gfunc = gfunc;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
 
-FT_Error  HB_GPOS_Register_MM_Function( HB_GPOSHeader*  gpos,
+HB_Error  HB_GPOS_Register_MM_Function( HB_GPOSHeader*  gpos,
 					HB_MMFunction   mmfunc,
 					void*            data )
 {
   if ( !gpos )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   gpos->mmfunc = mmfunc;
   gpos->data   = data;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 /* If `dvi' is TRUE, glyph contour points for anchor points and device
    tables are ignored -- you will get device independent values.         */
 
 
-FT_Error  HB_GPOS_Apply_String( FT_Face            face,
+HB_Error  HB_GPOS_Apply_String( FT_Face           face,
 				HB_GPOSHeader*    gpos,
-				FT_UShort          load_flags,
+				FT_UShort         load_flags,
 				HB_Buffer         buffer,
-				FT_Bool            dvi,
-				FT_Bool            r2l )
+				FT_Bool           dvi,
+				FT_Bool           r2l )
 {
-  FT_Error       error, retError = HB_Err_Not_Covered;
+  HB_Error       error, retError = HB_Err_Not_Covered;
   GPOS_Instance  gpi;
-  FT_UShort      i, j, feature_index, lookup_count;
-  HB_Feature    feature;
+  FT_UShort      i, j, lookup_count;
+
+  if ( !face || !gpos || !buffer )
+    return HB_Err_Invalid_Argument;
 
-  if ( !face || !gpos ||
-       !buffer || buffer->in_length == 0 || buffer->in_pos >= buffer->in_length )
-    return FT_Err_Invalid_Argument;
+  if ( buffer->in_length == 0 )
+    return HB_Err_Not_Covered;
 
   gpi.face       = face;
   gpi.gpos       = gpos;
@@ -6276,9 +6209,8 @@ FT_Error  HB_GPOS_Apply_String( FT_Face            face,
 
   for ( i = 0; i < gpos->FeatureList.ApplyCount; i++ )
   {
-    /* index of i'th feature */
-    feature_index = gpos->FeatureList.ApplyOrder[i];
-    feature = gpos->FeatureList.FeatureRecord[feature_index].Feature;
+    FT_UShort  feature_index = gpos->FeatureList.ApplyOrder[i];
+    HB_Feature feature = gpos->FeatureList.FeatureRecord[feature_index].Feature;
 
     for ( j = 0; j < feature.LookupListCount; j++ )
     {
diff --git a/pango/opentype/harfbuzz-gpos.h b/pango/opentype/harfbuzz-gpos.h
index 1c670279..2db7938a 100644
--- a/pango/opentype/harfbuzz-gpos.h
+++ b/pango/opentype/harfbuzz-gpos.h
@@ -48,7 +48,7 @@ FT_BEGIN_HEADER
 
       _glyph = HANDLE_Glyph( glyph )                                    */
 
-typedef FT_Error  (*HB_GlyphFunction)(FT_Face      face,
+typedef HB_Error  (*HB_GlyphFunction)(FT_Face      face,
 				       FT_UInt      glyphIndex,
 				       FT_Int       loadFlags );
 
@@ -64,7 +64,7 @@ typedef FT_Error  (*HB_GlyphFunction)(FT_Face      face,
    `metric_value' must be returned as a scaled value (but shouldn't
    be rounded).                                                       */
 
-typedef FT_Error  (*HB_MMFunction)(FT_Face      face,
+typedef HB_Error  (*HB_MMFunction)(FT_Face      face,
 				    FT_UShort    metric_id,
 				    FT_Pos*      metric_value,
 				    void*        data );
@@ -99,56 +99,56 @@ typedef struct HB_GPOSHeader_  HB_GPOSHeader;
 typedef HB_GPOSHeader* HB_GPOS;
 
 
-FT_Error  HB_Load_GPOS_Table( FT_Face          face,
+HB_Error  HB_Load_GPOS_Table( FT_Face          face,
 			      HB_GPOSHeader** gpos,
 			      HB_GDEFHeader*  gdef );
 
 
-FT_Error  HB_Done_GPOS_Table( HB_GPOSHeader* gpos );
+HB_Error  HB_Done_GPOS_Table( HB_GPOSHeader* gpos );
 
 
-FT_Error  HB_GPOS_Select_Script( HB_GPOSHeader*  gpos,
+HB_Error  HB_GPOS_Select_Script( HB_GPOSHeader*  gpos,
 				 FT_ULong         script_tag,
 				 FT_UShort*       script_index );
 
-FT_Error  HB_GPOS_Select_Language( HB_GPOSHeader*  gpos,
+HB_Error  HB_GPOS_Select_Language( HB_GPOSHeader*  gpos,
 				   FT_ULong         language_tag,
 				   FT_UShort        script_index,
 				   FT_UShort*       language_index,
 				   FT_UShort*       req_feature_index );
 
-FT_Error  HB_GPOS_Select_Feature( HB_GPOSHeader*  gpos,
+HB_Error  HB_GPOS_Select_Feature( HB_GPOSHeader*  gpos,
 				  FT_ULong         feature_tag,
 				  FT_UShort        script_index,
 				  FT_UShort        language_index,
 				  FT_UShort*       feature_index );
 
 
-FT_Error  HB_GPOS_Query_Scripts( HB_GPOSHeader*  gpos,
+HB_Error  HB_GPOS_Query_Scripts( HB_GPOSHeader*  gpos,
 				 FT_ULong**       script_tag_list );
 
-FT_Error  HB_GPOS_Query_Languages( HB_GPOSHeader*  gpos,
+HB_Error  HB_GPOS_Query_Languages( HB_GPOSHeader*  gpos,
 				   FT_UShort        script_index,
 				   FT_ULong**       language_tag_list );
 
-FT_Error  HB_GPOS_Query_Features( HB_GPOSHeader*  gpos,
+HB_Error  HB_GPOS_Query_Features( HB_GPOSHeader*  gpos,
 				  FT_UShort        script_index,
 				  FT_UShort        language_index,
 				  FT_ULong**       feature_tag_list );
 
 
-FT_Error  HB_GPOS_Add_Feature( HB_GPOSHeader*  gpos,
+HB_Error  HB_GPOS_Add_Feature( HB_GPOSHeader*  gpos,
 			       FT_UShort        feature_index,
 			       FT_UInt          property );
 
-FT_Error  HB_GPOS_Clear_Features( HB_GPOSHeader*  gpos );
+HB_Error  HB_GPOS_Clear_Features( HB_GPOSHeader*  gpos );
 
 
-FT_Error  HB_GPOS_Register_Glyph_Function( HB_GPOSHeader*    gpos,
+HB_Error  HB_GPOS_Register_Glyph_Function( HB_GPOSHeader*    gpos,
 					   HB_GlyphFunction  gfunc );
 
 
-FT_Error  HB_GPOS_Register_MM_Function( HB_GPOSHeader*  gpos,
+HB_Error  HB_GPOS_Register_MM_Function( HB_GPOSHeader*  gpos,
 					HB_MMFunction   mmfunc,
 					void*            data );
 
@@ -156,7 +156,7 @@ FT_Error  HB_GPOS_Register_MM_Function( HB_GPOSHeader*  gpos,
    tables are ignored -- you will get device independent values.         */
 
 
-FT_Error  HB_GPOS_Apply_String( FT_Face           face,
+HB_Error  HB_GPOS_Apply_String( FT_Face           face,
 				HB_GPOSHeader*   gpos,
 				FT_UShort         load_flags,
 				HB_Buffer        buffer,
diff --git a/pango/opentype/harfbuzz-gsub-private.h b/pango/opentype/harfbuzz-gsub-private.h
index 84c08df5..bc6d1b44 100644
--- a/pango/opentype/harfbuzz-gsub-private.h
+++ b/pango/opentype/harfbuzz-gsub-private.h
@@ -435,7 +435,7 @@ union  HB_GSUB_SubTable_
 
 
 
-FT_Error  _HB_GSUB_Load_SubTable( HB_GSUB_SubTable*  st,
+HB_Error  _HB_GSUB_Load_SubTable( HB_GSUB_SubTable*  st,
 				  FT_Stream     stream,
 				  FT_UShort     lookup_type );
 
diff --git a/pango/opentype/harfbuzz-gsub.c b/pango/opentype/harfbuzz-gsub.c
index 23b87b85..ab6721a7 100644
--- a/pango/opentype/harfbuzz-gsub.c
+++ b/pango/opentype/harfbuzz-gsub.c
@@ -4,6 +4,7 @@
  *  David Turner, Robert Wilhelm, and Werner Lemberg.
  *
  *  Copyright 2006  Behdad Esfahbod
+ *  Copyright 2007  Red Hat Software
  *
  *  This is part of HarfBuzz, an OpenType Layout engine library.
  *
@@ -15,7 +16,7 @@
 #include "harfbuzz-open-private.h"
 #include "harfbuzz-gdef-private.h"
 
-static FT_Error  GSUB_Do_Glyph_Lookup( HB_GSUBHeader*   gsub,
+static HB_Error  GSUB_Do_Glyph_Lookup( HB_GSUBHeader*   gsub,
 				       FT_UShort         lookup_index,
 				       HB_Buffer        buffer,
 				       FT_UShort         context_length,
@@ -29,13 +30,13 @@ static FT_Error  GSUB_Do_Glyph_Lookup( HB_GSUBHeader*   gsub,
 
 
 
-FT_Error  HB_Load_GSUB_Table( FT_Face          face,
+HB_Error  HB_Load_GSUB_Table( FT_Face          face,
 			      HB_GSUBHeader** retptr,
 			      HB_GDEFHeader*  gdef )
 {
   FT_Stream        stream = face->stream;
   FT_Memory        memory = face->memory;
-  FT_Error         error;
+  HB_Error         error;
   FT_ULong         cur_offset, new_offset, base_offset;
 
   FT_UShort        i, num_lookups;
@@ -43,7 +44,7 @@ FT_Error  HB_Load_GSUB_Table( FT_Face          face,
   HB_Lookup*      lo;
 
   if ( !retptr )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   if (( error = _hb_ftglue_face_goto_table( face, TTAG_GSUB, stream ) ))
     return error;
@@ -68,7 +69,7 @@ FT_Error  HB_Load_GSUB_Table( FT_Face          face,
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
        ( error = _HB_OPEN_Load_ScriptList( &gsub->ScriptList,
-				  stream ) ) != FT_Err_Ok )
+				  stream ) ) != HB_Err_Ok )
     goto Fail4;
   (void)FILE_Seek( cur_offset );
 
@@ -82,7 +83,7 @@ FT_Error  HB_Load_GSUB_Table( FT_Face          face,
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
        ( error = _HB_OPEN_Load_FeatureList( &gsub->FeatureList,
-				   stream ) ) != FT_Err_Ok )
+				   stream ) ) != HB_Err_Ok )
     goto Fail3;
   (void)FILE_Seek( cur_offset );
 
@@ -96,7 +97,7 @@ FT_Error  HB_Load_GSUB_Table( FT_Face          face,
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
        ( error = _HB_OPEN_Load_LookupList( &gsub->LookupList,
-				  stream, HB_Type_GSUB ) ) != FT_Err_Ok )
+				  stream, HB_Type_GSUB ) ) != HB_Err_Ok )
     goto Fail2;
 
   gsub->gdef = gdef;      /* can be NULL */
@@ -123,7 +124,7 @@ FT_Error  HB_Load_GSUB_Table( FT_Face          face,
       {
 	if ( FILE_Seek( gdef->MarkAttachClassDef_offset ) ||
 	     ( error = _HB_OPEN_Load_ClassDefinition( &gdef->MarkAttachClassDef,
-					     256, stream ) ) != FT_Err_Ok )
+					     256, stream ) ) != HB_Err_Ok )
 	  goto Fail1;
 
 	break;
@@ -133,7 +134,7 @@ FT_Error  HB_Load_GSUB_Table( FT_Face          face,
 
   *retptr = gsub;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   _HB_OPEN_Free_LookupList( &gsub->LookupList, HB_Type_GSUB, memory );
@@ -152,7 +153,7 @@ Fail4:
 }
 
 
-FT_Error   HB_Done_GSUB_Table( HB_GSUBHeader* gsub )
+HB_Error   HB_Done_GSUB_Table( HB_GSUBHeader* gsub )
 {
   FT_Memory memory = gsub->memory;
 
@@ -162,39 +163,23 @@ FT_Error   HB_Done_GSUB_Table( HB_GSUBHeader* gsub )
 
   FREE( gsub );
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 /*****************************
  * SubTable related functions
  *****************************/
 
-static FT_Error  Lookup_DefaultSubst( HB_GSUBHeader*    gsub,
-				      HB_GSUB_SubTable* st,
-				      HB_Buffer         buffer,
-				      FT_UShort          flags,
-				      FT_UShort          context_length,
-				      int                nesting_level )
-{
-  FT_UNUSED(gsub);
-  FT_UNUSED(st);
-  FT_UNUSED(buffer);
-  FT_UNUSED(flags);
-  FT_UNUSED(context_length);
-  FT_UNUSED(nesting_level);
-  return HB_Err_Not_Covered;
-}
-
 
 /* LookupType 1 */
 
 /* SingleSubstFormat1 */
 /* SingleSubstFormat2 */
 
-static FT_Error  Load_SingleSubst( HB_GSUB_SubTable* st,
+static HB_Error  Load_SingleSubst( HB_GSUB_SubTable* st,
 				   FT_Stream         stream )
 {
-  FT_Error error;
+  HB_Error error;
   FT_Memory memory = stream->memory;
   HB_SingleSubst*  ss = &st->single;
 
@@ -216,7 +201,7 @@ static FT_Error  Load_SingleSubst( HB_GSUB_SubTable* st,
 
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
-       ( error = _HB_OPEN_Load_Coverage( &ss->Coverage, stream ) ) != FT_Err_Ok )
+       ( error = _HB_OPEN_Load_Coverage( &ss->Coverage, stream ) ) != HB_Err_Ok )
     return error;
   (void)FILE_Seek( cur_offset );
 
@@ -258,10 +243,10 @@ static FT_Error  Load_SingleSubst( HB_GSUB_SubTable* st,
     break;
 
   default:
-    return HB_Err_Invalid_GSUB_SubTable_Format;
+    return _hb_err(HB_Err_Invalid_GSUB_SubTable_Format);
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   FREE( s );
@@ -285,13 +270,16 @@ static void  Free_SingleSubst( HB_GSUB_SubTable* st,
   case 2:
     FREE( ss->ssf.ssf2.Substitute );
     break;
+
+  default:
+    break;
   }
 
   _HB_OPEN_Free_Coverage( &ss->Coverage, memory );
 }
 
 
-static FT_Error  Lookup_SingleSubst( HB_GSUBHeader*   gsub,
+static HB_Error  Lookup_SingleSubst( HB_GSUBHeader*   gsub,
 				     HB_GSUB_SubTable* st,
 				     HB_Buffer        buffer,
 				     FT_UShort         flags,
@@ -299,13 +287,12 @@ static FT_Error  Lookup_SingleSubst( HB_GSUBHeader*   gsub,
 				     int               nesting_level )
 {
   FT_UShort index, value, property;
-  FT_Error  error;
+  HB_Error  error;
   HB_SingleSubst*  ss = &st->single;
   HB_GDEFHeader*   gdef = gsub->gdef;
 
   FT_UNUSED(nesting_level);
 
-
   if ( context_length != 0xFFFF && context_length < 1 )
     return HB_Err_Not_Covered;
 
@@ -319,21 +306,21 @@ static FT_Error  Lookup_SingleSubst( HB_GSUBHeader*   gsub,
   switch ( ss->SubstFormat )
   {
   case 1:
-	  value = ( IN_CURGLYPH() + ss->ssf.ssf1.DeltaGlyphID ) & 0xFFFF;
-    if ( ADD_Glyph( buffer, value, 0xFFFF, 0xFFFF ) )
+    value = (IN_CURGLYPH() + ss->ssf.ssf1.DeltaGlyphID ) & 0xFFFF;
+    if ( REPLACE_Glyph( buffer, value, nesting_level ) )
       return error;
     break;
 
   case 2:
     if ( index >= ss->ssf.ssf2.GlyphCount )
-      return HB_Err_Invalid_GSUB_SubTable;
+      return _hb_err(HB_Err_Invalid_GSUB_SubTable);
     value = ss->ssf.ssf2.Substitute[index];
-    if ( ADD_Glyph( buffer, value, 0xFFFF, 0xFFFF ) )
+    if ( REPLACE_Glyph( buffer, value, nesting_level ) )
       return error;
     break;
 
   default:
-    return HB_Err_Invalid_GSUB_SubTable;
+    return _hb_err(HB_Err_Invalid_GSUB_SubTable);
   }
 
   if ( gdef && gdef->NewGlyphClasses )
@@ -345,7 +332,7 @@ static FT_Error  Lookup_SingleSubst( HB_GSUBHeader*   gsub,
       return error;
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
@@ -353,10 +340,10 @@ static FT_Error  Lookup_SingleSubst( HB_GSUBHeader*   gsub,
 
 /* Sequence */
 
-static FT_Error  Load_Sequence( HB_Sequence*  s,
+static HB_Error  Load_Sequence( HB_Sequence*  s,
 				FT_Stream      stream )
 {
-  FT_Error error;
+  HB_Error error;
   FT_Memory memory = stream->memory;
 
   FT_UShort n, count;
@@ -391,7 +378,7 @@ static FT_Error  Load_Sequence( HB_Sequence*  s,
     FORGET_Frame();
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
@@ -404,10 +391,10 @@ static void  Free_Sequence( HB_Sequence*  s,
 
 /* MultipleSubstFormat1 */
 
-static FT_Error  Load_MultipleSubst( HB_GSUB_SubTable* st,
+static HB_Error  Load_MultipleSubst( HB_GSUB_SubTable* st,
 				     FT_Stream         stream )
 {
-  FT_Error error;
+  HB_Error error;
   FT_Memory memory = stream->memory;
   HB_MultipleSubst*  ms = &st->multiple;
 
@@ -429,7 +416,7 @@ static FT_Error  Load_MultipleSubst( HB_GSUB_SubTable* st,
 
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
-       ( error = _HB_OPEN_Load_Coverage( &ms->Coverage, stream ) ) != FT_Err_Ok )
+       ( error = _HB_OPEN_Load_Coverage( &ms->Coverage, stream ) ) != HB_Err_Ok )
     return error;
   (void)FILE_Seek( cur_offset );
 
@@ -458,12 +445,12 @@ static FT_Error  Load_MultipleSubst( HB_GSUB_SubTable* st,
 
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
-	 ( error = Load_Sequence( &s[n], stream ) ) != FT_Err_Ok )
+	 ( error = Load_Sequence( &s[n], stream ) ) != HB_Err_Ok )
       goto Fail1;
     (void)FILE_Seek( cur_offset );
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   for ( m = 0; m < n; m++ )
@@ -501,14 +488,14 @@ static void  Free_MultipleSubst( HB_GSUB_SubTable* st,
 }
 
 
-static FT_Error  Lookup_MultipleSubst( HB_GSUBHeader*    gsub,
+static HB_Error  Lookup_MultipleSubst( HB_GSUBHeader*    gsub,
 				       HB_GSUB_SubTable* st,
 				       HB_Buffer         buffer,
 				       FT_UShort          flags,
 				       FT_UShort          context_length,
 				       int                nesting_level )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_UShort index, property, n, count;
   FT_UShort*s;
   HB_MultipleSubst*  ms = &st->multiple;
@@ -527,7 +514,7 @@ static FT_Error  Lookup_MultipleSubst( HB_GSUBHeader*    gsub,
     return error;
 
   if ( index >= ms->SequenceCount )
-    return HB_Err_Invalid_GSUB_SubTable;
+    return _hb_err(HB_Err_Invalid_GSUB_SubTable);
 
   count = ms->Sequence[index].GlyphCount;
   s     = ms->Sequence[index].Substitute;
@@ -550,7 +537,7 @@ static FT_Error  Lookup_MultipleSubst( HB_GSUBHeader*    gsub,
     }
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
@@ -558,10 +545,10 @@ static FT_Error  Lookup_MultipleSubst( HB_GSUBHeader*    gsub,
 
 /* AlternateSet */
 
-static FT_Error  Load_AlternateSet( HB_AlternateSet*  as,
+static HB_Error  Load_AlternateSet( HB_AlternateSet*  as,
 				    FT_Stream          stream )
 {
-  FT_Error error;
+  HB_Error error;
   FT_Memory memory = stream->memory;
 
   FT_UShort n, count;
@@ -593,7 +580,7 @@ static FT_Error  Load_AlternateSet( HB_AlternateSet*  as,
 
   FORGET_Frame();
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
@@ -606,10 +593,10 @@ static void  Free_AlternateSet( HB_AlternateSet*  as,
 
 /* AlternateSubstFormat1 */
 
-static FT_Error  Load_AlternateSubst( HB_GSUB_SubTable* st,
+static HB_Error  Load_AlternateSubst( HB_GSUB_SubTable* st,
 				      FT_Stream         stream )
 {
-  FT_Error error;
+  HB_Error error;
   FT_Memory memory = stream->memory;
   HB_AlternateSubst* as = &st->alternate;
 
@@ -631,7 +618,7 @@ static FT_Error  Load_AlternateSubst( HB_GSUB_SubTable* st,
 
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
-       ( error = _HB_OPEN_Load_Coverage( &as->Coverage, stream ) ) != FT_Err_Ok )
+       ( error = _HB_OPEN_Load_Coverage( &as->Coverage, stream ) ) != HB_Err_Ok )
     return error;
   (void)FILE_Seek( cur_offset );
 
@@ -660,12 +647,12 @@ static FT_Error  Load_AlternateSubst( HB_GSUB_SubTable* st,
 
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
-	 ( error = Load_AlternateSet( &aset[n], stream ) ) != FT_Err_Ok )
+	 ( error = Load_AlternateSet( &aset[n], stream ) ) != HB_Err_Ok )
       goto Fail1;
     (void)FILE_Seek( cur_offset );
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   for ( m = 0; m < n; m++ )
@@ -703,15 +690,15 @@ static void  Free_AlternateSubst( HB_GSUB_SubTable* st,
 }
 
 
-static FT_Error  Lookup_AlternateSubst( HB_GSUBHeader*    gsub,
+static HB_Error  Lookup_AlternateSubst( HB_GSUBHeader*    gsub,
 					HB_GSUB_SubTable* st,
 					HB_Buffer         buffer,
 					FT_UShort          flags,
 					FT_UShort          context_length,
 					int                nesting_level )
 {
-  FT_Error          error;
-  FT_UShort         index, alt_index, property;
+  HB_Error          error;
+  FT_UShort         index, value, alt_index, property;
   HB_AlternateSubst* as = &st->alternate;
   HB_GDEFHeader*     gdef = gsub->gdef;
   HB_AlternateSet  aset;
@@ -739,21 +726,20 @@ static FT_Error  Lookup_AlternateSubst( HB_GSUBHeader*    gsub,
   else
     alt_index = 0;
 
-  if ( ADD_Glyph( buffer, aset.Alternate[alt_index],
-		  0xFFFF, 0xFFFF ) )
+  value = aset.Alternate[alt_index];
+  if ( REPLACE_Glyph( buffer, value, nesting_level ) )
     return error;
 
   if ( gdef && gdef->NewGlyphClasses )
   {
     /* we inherit the old glyph class to the substituted glyph */
 
-    error = _HB_GDEF_Add_Glyph_Property( gdef, aset.Alternate[alt_index],
-				property );
+    error = _HB_GDEF_Add_Glyph_Property( gdef, value, property );
     if ( error && error != HB_Err_Not_Covered )
       return error;
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
@@ -761,10 +747,10 @@ static FT_Error  Lookup_AlternateSubst( HB_GSUBHeader*    gsub,
 
 /* Ligature */
 
-static FT_Error  Load_Ligature( HB_Ligature*  l,
+static HB_Error  Load_Ligature( HB_Ligature*  l,
 				FT_Stream      stream )
 {
-  FT_Error error;
+  HB_Error error;
   FT_Memory memory = stream->memory;
 
   FT_UShort n, count;
@@ -799,7 +785,7 @@ static FT_Error  Load_Ligature( HB_Ligature*  l,
 
   FORGET_Frame();
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
@@ -812,10 +798,10 @@ static void  Free_Ligature( HB_Ligature*  l,
 
 /* LigatureSet */
 
-static FT_Error  Load_LigatureSet( HB_LigatureSet*  ls,
+static HB_Error  Load_LigatureSet( HB_LigatureSet*  ls,
 				   FT_Stream         stream )
 {
-  FT_Error error;
+  HB_Error error;
   FT_Memory memory = stream->memory;
 
   FT_UShort      n = 0, m, count;
@@ -851,12 +837,12 @@ static FT_Error  Load_LigatureSet( HB_LigatureSet*  ls,
 
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
-	 ( error = Load_Ligature( &l[n], stream ) ) != FT_Err_Ok )
+	 ( error = Load_Ligature( &l[n], stream ) ) != HB_Err_Ok )
       goto Fail;
     (void)FILE_Seek( cur_offset );
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail:
   for ( m = 0; m < n; m++ )
@@ -890,10 +876,10 @@ static void  Free_LigatureSet( HB_LigatureSet*  ls,
 
 /* LigatureSubstFormat1 */
 
-static FT_Error  Load_LigatureSubst( HB_GSUB_SubTable* st,
+static HB_Error  Load_LigatureSubst( HB_GSUB_SubTable* st,
 				     FT_Stream         stream )
 {
-  FT_Error error;
+  HB_Error error;
   FT_Memory memory = stream->memory;
   HB_LigatureSubst*  ls = &st->ligature;
 
@@ -915,7 +901,7 @@ static FT_Error  Load_LigatureSubst( HB_GSUB_SubTable* st,
 
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
-       ( error = _HB_OPEN_Load_Coverage( &ls->Coverage, stream ) ) != FT_Err_Ok )
+       ( error = _HB_OPEN_Load_Coverage( &ls->Coverage, stream ) ) != HB_Err_Ok )
     return error;
   (void)FILE_Seek( cur_offset );
 
@@ -944,12 +930,12 @@ static FT_Error  Load_LigatureSubst( HB_GSUB_SubTable* st,
 
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
-	 ( error = Load_LigatureSet( &lset[n], stream ) ) != FT_Err_Ok )
+	 ( error = Load_LigatureSet( &lset[n], stream ) ) != HB_Err_Ok )
       goto Fail1;
     (void)FILE_Seek( cur_offset );
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   for ( m = 0; m < n; m++ )
@@ -987,7 +973,7 @@ static void  Free_LigatureSubst( HB_GSUB_SubTable* st,
 }
 
 
-static FT_Error  Lookup_LigatureSubst( HB_GSUBHeader*    gsub,
+static HB_Error  Lookup_LigatureSubst( HB_GSUBHeader*    gsub,
 				       HB_GSUB_SubTable* st,
 				       HB_Buffer         buffer,
 				       FT_UShort          flags,
@@ -995,7 +981,7 @@ static FT_Error  Lookup_LigatureSubst( HB_GSUBHeader*    gsub,
 				       int                nesting_level )
 {
   FT_UShort      index, property;
-  FT_Error       error;
+  HB_Error       error;
   FT_UShort      numlig, i, j, is_mark, first_is_mark = FALSE;
   FT_UShort*     c;
   HB_LigatureSubst*  ls = &st->ligature;
@@ -1016,7 +1002,7 @@ static FT_Error  Lookup_LigatureSubst( HB_GSUBHeader*    gsub,
     return error;
 
   if ( index >= ls->LigatureSetCount )
-     return HB_Err_Invalid_GSUB_SubTable;
+     return _hb_err(HB_Err_Invalid_GSUB_SubTable);
 
   lig = ls->LigatureSet[index].Ligature;
 
@@ -1085,8 +1071,7 @@ static FT_Error  Lookup_LigatureSubst( HB_GSUBHeader*    gsub,
     else
     {
       FT_UShort ligID = hb_buffer_allocate_ligid( buffer );
-      if ( ADD_Glyph( buffer, lig->LigGlyph,
-		      0xFFFF, ligID ) )
+      if ( ADD_Glyph( buffer, lig->LigGlyph, 0xFFFF, ligID ) )
 	return error;
 
       /* Now we must do a second loop to copy the skipped glyphs to
@@ -1100,15 +1085,14 @@ static FT_Error  Lookup_LigatureSubst( HB_GSUBHeader*    gsub,
       {
 	while ( CHECK_Property( gdef, IN_CURITEM(),
 				flags, &property ) )
-	  if ( ADD_Glyph( buffer, IN_CURGLYPH(),
-			  i, ligID ) )
+	  if ( ADD_Glyph( buffer, IN_CURGLYPH(), i, ligID ) )
 	    return error;
 
 	(buffer->in_pos)++;
       }
     }
 
-    return FT_Err_Ok;
+    return HB_Err_Ok;
 
   next_ligature:
     ;
@@ -1122,14 +1106,14 @@ static FT_Error  Lookup_LigatureSubst( HB_GSUBHeader*    gsub,
    5 or 6).  This is only called after we've determined that the input
    matches the subrule.                                                 */
 
-static FT_Error  Do_ContextSubst( HB_GSUBHeader*        gsub,
+static HB_Error  Do_ContextSubst( HB_GSUBHeader*        gsub,
 				  FT_UShort              GlyphCount,
 				  FT_UShort              SubstCount,
 				  HB_SubstLookupRecord* subst,
 				  HB_Buffer             buffer,
 				  int                    nesting_level )
 {
-  FT_Error  error;
+  HB_Error  error;
   FT_ULong i, old_pos;
 
 
@@ -1152,10 +1136,7 @@ static FT_Error  Do_ContextSubst( HB_GSUBHeader*        gsub,
 
       if ( error == HB_Err_Not_Covered )
       {
-	/* XXX "can't happen" -- but don't count on it */
-
-	if ( ADD_Glyph( buffer, IN_CURGLYPH(),
-			0xFFFF, 0xFFFF ) )
+	if ( COPY_Glyph( buffer ) )
 	  return error;
 	i++;
       }
@@ -1166,14 +1147,13 @@ static FT_Error  Do_ContextSubst( HB_GSUBHeader*        gsub,
     {
       /* No substitution for this index */
 
-      if ( ADD_Glyph( buffer, IN_CURGLYPH(),
-		      0xFFFF, 0xFFFF ) )
+      if ( COPY_Glyph( buffer ) )
 	return error;
       i++;
     }
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
@@ -1181,10 +1161,10 @@ static FT_Error  Do_ContextSubst( HB_GSUBHeader*        gsub,
 
 /* SubRule */
 
-static FT_Error  Load_SubRule( HB_SubRule*  sr,
+static HB_Error  Load_SubRule( HB_SubRule*  sr,
 			       FT_Stream     stream )
 {
-  FT_Error error;
+  HB_Error error;
   FT_Memory memory = stream->memory;
 
   FT_UShort               n, count;
@@ -1238,7 +1218,7 @@ static FT_Error  Load_SubRule( HB_SubRule*  sr,
 
   FORGET_Frame();
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   FREE( slr );
@@ -1259,10 +1239,10 @@ static void  Free_SubRule( HB_SubRule*  sr,
 
 /* SubRuleSet */
 
-static FT_Error  Load_SubRuleSet( HB_SubRuleSet*  srs,
+static HB_Error  Load_SubRuleSet( HB_SubRuleSet*  srs,
 				  FT_Stream        stream )
 {
-  FT_Error error;
+  HB_Error error;
   FT_Memory memory = stream->memory;
 
   FT_UShort     n = 0, m, count;
@@ -1298,12 +1278,12 @@ static FT_Error  Load_SubRuleSet( HB_SubRuleSet*  srs,
 
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
-	 ( error = Load_SubRule( &sr[n], stream ) ) != FT_Err_Ok )
+	 ( error = Load_SubRule( &sr[n], stream ) ) != HB_Err_Ok )
       goto Fail;
     (void)FILE_Seek( cur_offset );
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail:
   for ( m = 0; m < n; m++ )
@@ -1337,10 +1317,10 @@ static void  Free_SubRuleSet( HB_SubRuleSet*  srs,
 
 /* ContextSubstFormat1 */
 
-static FT_Error  Load_ContextSubst1( HB_ContextSubstFormat1*  csf1,
+static HB_Error  Load_ContextSubst1( HB_ContextSubstFormat1*  csf1,
 				     FT_Stream                 stream )
 {
-  FT_Error error;
+  HB_Error error;
   FT_Memory memory = stream->memory;
 
   FT_UShort        n = 0, m, count;
@@ -1360,7 +1340,7 @@ static FT_Error  Load_ContextSubst1( HB_ContextSubstFormat1*  csf1,
 
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
-       ( error = _HB_OPEN_Load_Coverage( &csf1->Coverage, stream ) ) != FT_Err_Ok )
+       ( error = _HB_OPEN_Load_Coverage( &csf1->Coverage, stream ) ) != HB_Err_Ok )
     return error;
   (void)FILE_Seek( cur_offset );
 
@@ -1389,12 +1369,12 @@ static FT_Error  Load_ContextSubst1( HB_ContextSubstFormat1*  csf1,
 
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
-	 ( error = Load_SubRuleSet( &srs[n], stream ) ) != FT_Err_Ok )
+	 ( error = Load_SubRuleSet( &srs[n], stream ) ) != HB_Err_Ok )
       goto Fail1;
     (void)FILE_Seek( cur_offset );
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   for ( m = 0; m < n; m++ )
@@ -1433,11 +1413,11 @@ static void  Free_ContextSubst1( HB_ContextSubstFormat1* csf1,
 
 /* SubClassRule */
 
-static FT_Error  Load_SubClassRule( HB_ContextSubstFormat2*  csf2,
+static HB_Error  Load_SubClassRule( HB_ContextSubstFormat2*  csf2,
 				    HB_SubClassRule*         scr,
 				    FT_Stream                 stream )
 {
-  FT_Error error;
+  HB_Error error;
   FT_Memory memory = stream->memory;
 
   FT_UShort               n, count;
@@ -1503,7 +1483,7 @@ static FT_Error  Load_SubClassRule( HB_ContextSubstFormat2*  csf2,
 
   FORGET_Frame();
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   FREE( slr );
@@ -1524,11 +1504,11 @@ static void  Free_SubClassRule( HB_SubClassRule*  scr,
 
 /* SubClassSet */
 
-static FT_Error  Load_SubClassSet( HB_ContextSubstFormat2*  csf2,
+static HB_Error  Load_SubClassSet( HB_ContextSubstFormat2*  csf2,
 				   HB_SubClassSet*          scs,
 				   FT_Stream                 stream )
 {
-  FT_Error error;
+  HB_Error error;
   FT_Memory memory = stream->memory;
 
   FT_UShort          n = 0, m, count;
@@ -1565,12 +1545,12 @@ static FT_Error  Load_SubClassSet( HB_ContextSubstFormat2*  csf2,
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
 	 ( error = Load_SubClassRule( csf2, &scr[n],
-				      stream ) ) != FT_Err_Ok )
+				      stream ) ) != HB_Err_Ok )
       goto Fail;
     (void)FILE_Seek( cur_offset );
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail:
   for ( m = 0; m < n; m++ )
@@ -1604,10 +1584,10 @@ static void  Free_SubClassSet( HB_SubClassSet*  scs,
 
 /* ContextSubstFormat2 */
 
-static FT_Error  Load_ContextSubst2( HB_ContextSubstFormat2*  csf2,
+static HB_Error  Load_ContextSubst2( HB_ContextSubstFormat2*  csf2,
 				     FT_Stream                 stream )
 {
-  FT_Error error;
+  HB_Error error;
   FT_Memory memory = stream->memory;
 
   FT_UShort         n = 0, m, count;
@@ -1627,7 +1607,7 @@ static FT_Error  Load_ContextSubst2( HB_ContextSubstFormat2*  csf2,
 
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
-       ( error = _HB_OPEN_Load_Coverage( &csf2->Coverage, stream ) ) != FT_Err_Ok )
+       ( error = _HB_OPEN_Load_Coverage( &csf2->Coverage, stream ) ) != HB_Err_Ok )
     return error;
   (void)FILE_Seek( cur_offset );
 
@@ -1646,7 +1626,7 @@ static FT_Error  Load_ContextSubst2( HB_ContextSubstFormat2*  csf2,
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
        ( error = _HB_OPEN_Load_ClassDefinition( &csf2->ClassDef, count,
-				       stream ) ) != FT_Err_Ok )
+				       stream ) ) != HB_Err_Ok )
     goto Fail3;
   (void)FILE_Seek( cur_offset );
 
@@ -1672,7 +1652,7 @@ static FT_Error  Load_ContextSubst2( HB_ContextSubstFormat2*  csf2,
       cur_offset = FILE_Pos();
       if ( FILE_Seek( new_offset ) ||
 	   ( error = Load_SubClassSet( csf2, &scs[n],
-				       stream ) ) != FT_Err_Ok )
+				       stream ) ) != HB_Err_Ok )
 	goto Fail1;
       (void)FILE_Seek( cur_offset );
     }
@@ -1685,7 +1665,7 @@ static FT_Error  Load_ContextSubst2( HB_ContextSubstFormat2*  csf2,
     }
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   for ( m = 0; m < n; m++ )
@@ -1728,10 +1708,10 @@ static void  Free_ContextSubst2( HB_ContextSubstFormat2*  csf2,
 
 /* ContextSubstFormat3 */
 
-static FT_Error  Load_ContextSubst3( HB_ContextSubstFormat3*  csf3,
+static HB_Error  Load_ContextSubst3( HB_ContextSubstFormat3*  csf3,
 				     FT_Stream                 stream )
 {
-  FT_Error error;
+  HB_Error error;
   FT_Memory memory = stream->memory;
 
   FT_UShort               n = 0, m, count;
@@ -1771,7 +1751,7 @@ static FT_Error  Load_ContextSubst3( HB_ContextSubstFormat3*  csf3,
 
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
-	 ( error = _HB_OPEN_Load_Coverage( &c[n], stream ) ) != FT_Err_Ok )
+	 ( error = _HB_OPEN_Load_Coverage( &c[n], stream ) ) != HB_Err_Ok )
       goto Fail2;
     (void)FILE_Seek( cur_offset );
   }
@@ -1797,7 +1777,7 @@ static FT_Error  Load_ContextSubst3( HB_ContextSubstFormat3*  csf3,
 
   FORGET_Frame();
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   FREE( slr );
@@ -1836,10 +1816,10 @@ static void  Free_ContextSubst3( HB_ContextSubstFormat3*  csf3,
 
 /* ContextSubst */
 
-static FT_Error  Load_ContextSubst( HB_GSUB_SubTable* st,
+static HB_Error  Load_ContextSubst( HB_GSUB_SubTable* st,
 				    FT_Stream         stream )
 {
-  FT_Error error;
+  HB_Error error;
   HB_ContextSubst*  cs = &st->context;
 
 
@@ -1852,20 +1832,13 @@ static FT_Error  Load_ContextSubst( HB_GSUB_SubTable* st,
 
   switch ( cs->SubstFormat )
   {
-  case 1:
-    return Load_ContextSubst1( &cs->csf.csf1, stream );
-
-  case 2:
-    return Load_ContextSubst2( &cs->csf.csf2, stream );
-
-  case 3:
-    return Load_ContextSubst3( &cs->csf.csf3, stream );
-
-  default:
-    return HB_Err_Invalid_GSUB_SubTable_Format;
+  case 1:  return Load_ContextSubst1( &cs->csf.csf1, stream );
+  case 2:  return Load_ContextSubst2( &cs->csf.csf2, stream );
+  case 3:  return Load_ContextSubst3( &cs->csf.csf3, stream );
+  default: return _hb_err(HB_Err_Invalid_GSUB_SubTable_Format);
   }
 
-  return FT_Err_Ok;               /* never reached */
+  return HB_Err_Ok;               /* never reached */
 }
 
 
@@ -1876,22 +1849,15 @@ static void  Free_ContextSubst( HB_GSUB_SubTable* st,
 
   switch ( cs->SubstFormat )
   {
-  case 1:
-    Free_ContextSubst1( &cs->csf.csf1, memory );
-    break;
-
-  case 2:
-    Free_ContextSubst2( &cs->csf.csf2, memory );
-    break;
-
-  case 3:
-    Free_ContextSubst3( &cs->csf.csf3, memory );
-    break;
+  case 1:  Free_ContextSubst1( &cs->csf.csf1, memory ); break;
+  case 2:  Free_ContextSubst2( &cs->csf.csf2, memory ); break;
+  case 3:  Free_ContextSubst3( &cs->csf.csf3, memory ); break;
+  default:						break;
   }
 }
 
 
-static FT_Error  Lookup_ContextSubst1( HB_GSUBHeader*          gsub,
+static HB_Error  Lookup_ContextSubst1( HB_GSUBHeader*          gsub,
 				       HB_ContextSubstFormat1* csf1,
 				       HB_Buffer               buffer,
 				       FT_UShort                flags,
@@ -1900,7 +1866,7 @@ static FT_Error  Lookup_ContextSubst1( HB_GSUBHeader*          gsub,
 {
   FT_UShort        index, property;
   FT_UShort        i, j, k, numsr;
-  FT_Error         error;
+  HB_Error         error;
 
   HB_SubRule*     sr;
   HB_GDEFHeader*  gdef;
@@ -1954,7 +1920,7 @@ static FT_Error  Lookup_ContextSubst1( HB_GSUBHeader*          gsub,
 }
 
 
-static FT_Error  Lookup_ContextSubst2( HB_GSUBHeader*          gsub,
+static HB_Error  Lookup_ContextSubst2( HB_GSUBHeader*          gsub,
 				       HB_ContextSubstFormat2* csf2,
 				       HB_Buffer               buffer,
 				       FT_UShort                flags,
@@ -1962,7 +1928,7 @@ static FT_Error  Lookup_ContextSubst2( HB_GSUBHeader*          gsub,
 				       int                      nesting_level )
 {
   FT_UShort          index, property;
-  FT_Error           error;
+  HB_Error           error;
   FT_Memory          memory = gsub->memory;
   FT_UShort          i, j, k, known_classes;
 
@@ -1999,7 +1965,7 @@ static FT_Error  Lookup_ContextSubst2( HB_GSUBHeader*          gsub,
   scs = &csf2->SubClassSet[classes[0]];
   if ( !scs )
   {
-    error = HB_Err_Invalid_GSUB_SubTable;
+    error = _hb_err(HB_Err_Invalid_GSUB_SubTable);
     goto End;
   }
 
@@ -2061,14 +2027,14 @@ End:
 }
 
 
-static FT_Error  Lookup_ContextSubst3( HB_GSUBHeader*          gsub,
+static HB_Error  Lookup_ContextSubst3( HB_GSUBHeader*          gsub,
 				       HB_ContextSubstFormat3* csf3,
 				       HB_Buffer               buffer,
 				       FT_UShort                flags,
 				       FT_UShort                context_length,
 				       int                      nesting_level )
 {
-  FT_Error         error;
+  HB_Error         error;
   FT_UShort        index, i, j, property;
 
   HB_Coverage*    c;
@@ -2112,7 +2078,7 @@ static FT_Error  Lookup_ContextSubst3( HB_GSUBHeader*          gsub,
 }
 
 
-static FT_Error  Lookup_ContextSubst( HB_GSUBHeader*    gsub,
+static HB_Error  Lookup_ContextSubst( HB_GSUBHeader*    gsub,
 				      HB_GSUB_SubTable* st,
 				      HB_Buffer         buffer,
 				      FT_UShort          flags,
@@ -2123,23 +2089,13 @@ static FT_Error  Lookup_ContextSubst( HB_GSUBHeader*    gsub,
 
   switch ( cs->SubstFormat )
   {
-  case 1:
-    return Lookup_ContextSubst1( gsub, &cs->csf.csf1, buffer,
-				 flags, context_length, nesting_level );
-
-  case 2:
-    return Lookup_ContextSubst2( gsub, &cs->csf.csf2, buffer,
-				 flags, context_length, nesting_level );
-
-  case 3:
-    return Lookup_ContextSubst3( gsub, &cs->csf.csf3, buffer,
-				 flags, context_length, nesting_level );
-
-  default:
-    return HB_Err_Invalid_GSUB_SubTable_Format;
+  case 1:  return Lookup_ContextSubst1( gsub, &cs->csf.csf1, buffer, flags, context_length, nesting_level );
+  case 2:  return Lookup_ContextSubst2( gsub, &cs->csf.csf2, buffer, flags, context_length, nesting_level );
+  case 3:  return Lookup_ContextSubst3( gsub, &cs->csf.csf3, buffer, flags, context_length, nesting_level );
+  default: return _hb_err(HB_Err_Invalid_GSUB_SubTable_Format);
   }
 
-  return FT_Err_Ok;               /* never reached */
+  return HB_Err_Ok;               /* never reached */
 }
 
 
@@ -2147,10 +2103,10 @@ static FT_Error  Lookup_ContextSubst( HB_GSUBHeader*    gsub,
 
 /* ChainSubRule */
 
-static FT_Error  Load_ChainSubRule( HB_ChainSubRule*  csr,
+static HB_Error  Load_ChainSubRule( HB_ChainSubRule*  csr,
 				    FT_Stream          stream )
 {
-  FT_Error error;
+  HB_Error error;
   FT_Memory memory = stream->memory;
 
   FT_UShort               n, count;
@@ -2260,7 +2216,7 @@ static FT_Error  Load_ChainSubRule( HB_ChainSubRule*  csr,
 
   FORGET_Frame();
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   FREE( slr );
@@ -2289,10 +2245,10 @@ static void  Free_ChainSubRule( HB_ChainSubRule*  csr,
 
 /* ChainSubRuleSet */
 
-static FT_Error  Load_ChainSubRuleSet( HB_ChainSubRuleSet*  csrs,
+static HB_Error  Load_ChainSubRuleSet( HB_ChainSubRuleSet*  csrs,
 				       FT_Stream             stream )
 {
-  FT_Error error;
+  HB_Error error;
   FT_Memory memory = stream->memory;
 
   FT_UShort          n = 0, m, count;
@@ -2328,12 +2284,12 @@ static FT_Error  Load_ChainSubRuleSet( HB_ChainSubRuleSet*  csrs,
 
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
-	 ( error = Load_ChainSubRule( &csr[n], stream ) ) != FT_Err_Ok )
+	 ( error = Load_ChainSubRule( &csr[n], stream ) ) != HB_Err_Ok )
       goto Fail;
     (void)FILE_Seek( cur_offset );
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail:
   for ( m = 0; m < n; m++ )
@@ -2367,11 +2323,11 @@ static void  Free_ChainSubRuleSet( HB_ChainSubRuleSet*  csrs,
 
 /* ChainContextSubstFormat1 */
 
-static FT_Error  Load_ChainContextSubst1(
+static HB_Error  Load_ChainContextSubst1(
 		   HB_ChainContextSubstFormat1*  ccsf1,
 		   FT_Stream                      stream )
 {
-  FT_Error error;
+  HB_Error error;
   FT_Memory memory = stream->memory;
 
   FT_UShort             n = 0, m, count;
@@ -2391,7 +2347,7 @@ static FT_Error  Load_ChainContextSubst1(
 
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
-       ( error = _HB_OPEN_Load_Coverage( &ccsf1->Coverage, stream ) ) != FT_Err_Ok )
+       ( error = _HB_OPEN_Load_Coverage( &ccsf1->Coverage, stream ) ) != HB_Err_Ok )
     return error;
   (void)FILE_Seek( cur_offset );
 
@@ -2420,12 +2376,12 @@ static FT_Error  Load_ChainContextSubst1(
 
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
-	 ( error = Load_ChainSubRuleSet( &csrs[n], stream ) ) != FT_Err_Ok )
+	 ( error = Load_ChainSubRuleSet( &csrs[n], stream ) ) != HB_Err_Ok )
       goto Fail1;
     (void)FILE_Seek( cur_offset );
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   for ( m = 0; m < n; m++ )
@@ -2464,12 +2420,12 @@ static void  Free_ChainContextSubst1( HB_ChainContextSubstFormat1*  ccsf1,
 
 /* ChainSubClassRule */
 
-static FT_Error  Load_ChainSubClassRule(
+static HB_Error  Load_ChainSubClassRule(
 		   HB_ChainContextSubstFormat2*  ccsf2,
 		   HB_ChainSubClassRule*         cscr,
 		   FT_Stream                      stream )
 {
-  FT_Error error;
+  HB_Error error;
   FT_Memory memory = stream->memory;
 
   FT_UShort               n, count;
@@ -2611,7 +2567,7 @@ static FT_Error  Load_ChainSubClassRule(
 
   FORGET_Frame();
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   FREE( slr );
@@ -2640,12 +2596,12 @@ static void  Free_ChainSubClassRule( HB_ChainSubClassRule*  cscr,
 
 /* SubClassSet */
 
-static FT_Error  Load_ChainSubClassSet(
+static HB_Error  Load_ChainSubClassSet(
 		   HB_ChainContextSubstFormat2*  ccsf2,
 		   HB_ChainSubClassSet*          cscs,
 		   FT_Stream                      stream )
 {
-  FT_Error error;
+  HB_Error error;
   FT_Memory memory = stream->memory;
 
   FT_UShort               n = 0, m, count;
@@ -2683,12 +2639,12 @@ static FT_Error  Load_ChainSubClassSet(
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
 	 ( error = Load_ChainSubClassRule( ccsf2, &cscr[n],
-					   stream ) ) != FT_Err_Ok )
+					   stream ) ) != HB_Err_Ok )
       goto Fail;
     (void)FILE_Seek( cur_offset );
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail:
   for ( m = 0; m < n; m++ )
@@ -2719,13 +2675,13 @@ static void  Free_ChainSubClassSet( HB_ChainSubClassSet*  cscs,
   }
 }
 
-static FT_Error GSUB_Load_EmptyOrClassDefinition( HB_ClassDefinition*  cd,
+static HB_Error GSUB_Load_EmptyOrClassDefinition( HB_ClassDefinition*  cd,
 					     FT_UShort             limit,
 					     FT_ULong              class_offset,
 					     FT_ULong              base_offset,
 					     FT_Stream             stream )
 {
-  FT_Error error;
+  HB_Error error;
   FT_ULong               cur_offset;
 
   cur_offset = FILE_Pos();
@@ -2738,7 +2694,7 @@ static FT_Error GSUB_Load_EmptyOrClassDefinition( HB_ClassDefinition*  cd,
   else
      error = _HB_OPEN_Load_EmptyClassDefinition ( cd, stream );
 
-  if (error == FT_Err_Ok)
+  if (error == HB_Err_Ok)
     (void)FILE_Seek( cur_offset ); /* Changes error as a side-effect */
 
   return error;
@@ -2747,11 +2703,11 @@ static FT_Error GSUB_Load_EmptyOrClassDefinition( HB_ClassDefinition*  cd,
 
 /* ChainContextSubstFormat2 */
 
-static FT_Error  Load_ChainContextSubst2(
+static HB_Error  Load_ChainContextSubst2(
 		   HB_ChainContextSubstFormat2*  ccsf2,
 		   FT_Stream                      stream )
 {
-  FT_Error error;
+  HB_Error error;
   FT_Memory memory = stream->memory;
 
   FT_UShort              n = 0, m, count;
@@ -2772,7 +2728,7 @@ static FT_Error  Load_ChainContextSubst2(
 
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
-       ( error = _HB_OPEN_Load_Coverage( &ccsf2->Coverage, stream ) ) != FT_Err_Ok )
+       ( error = _HB_OPEN_Load_Coverage( &ccsf2->Coverage, stream ) ) != HB_Err_Ok )
     return error;
   (void)FILE_Seek( cur_offset );
 
@@ -2793,16 +2749,16 @@ static FT_Error  Load_ChainContextSubst2(
 
   if ( ( error = GSUB_Load_EmptyOrClassDefinition( &ccsf2->BacktrackClassDef, 65535,
 					      backtrack_offset, base_offset,
-					      stream ) ) != FT_Err_Ok )
+					      stream ) ) != HB_Err_Ok )
       goto Fail5;
 
   if ( ( error = GSUB_Load_EmptyOrClassDefinition( &ccsf2->InputClassDef, count,
 					      input_offset, base_offset,
-					      stream ) ) != FT_Err_Ok )
+					      stream ) ) != HB_Err_Ok )
       goto Fail4;
   if ( ( error = GSUB_Load_EmptyOrClassDefinition( &ccsf2->LookaheadClassDef, 65535,
 					      lookahead_offset, base_offset,
-					      stream ) ) != FT_Err_Ok )
+					      stream ) ) != HB_Err_Ok )
     goto Fail3;
 
   ccsf2->ChainSubClassSet   = NULL;
@@ -2829,7 +2785,7 @@ static FT_Error  Load_ChainContextSubst2(
       cur_offset = FILE_Pos();
       if ( FILE_Seek( new_offset ) ||
 	   ( error = Load_ChainSubClassSet( ccsf2, &cscs[n],
-					    stream ) ) != FT_Err_Ok )
+					    stream ) ) != HB_Err_Ok )
 	goto Fail1;
       (void)FILE_Seek( cur_offset );
     }
@@ -2842,7 +2798,7 @@ static FT_Error  Load_ChainContextSubst2(
     }
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   for ( m = 0; m < n; m++ )
@@ -2894,11 +2850,11 @@ static void  Free_ChainContextSubst2( HB_ChainContextSubstFormat2*  ccsf2,
 
 /* ChainContextSubstFormat3 */
 
-static FT_Error  Load_ChainContextSubst3(
+static HB_Error  Load_ChainContextSubst3(
 		   HB_ChainContextSubstFormat3*  ccsf3,
 		   FT_Stream                      stream )
 {
-  FT_Error error;
+  HB_Error error;
   FT_Memory memory = stream->memory;
 
   FT_UShort               n, nb = 0, ni =0, nl = 0, m, count;
@@ -2941,7 +2897,7 @@ static FT_Error  Load_ChainContextSubst3(
 
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
-	 ( error = _HB_OPEN_Load_Coverage( &b[nb], stream ) ) != FT_Err_Ok )
+	 ( error = _HB_OPEN_Load_Coverage( &b[nb], stream ) ) != HB_Err_Ok )
       goto Fail4;
     (void)FILE_Seek( cur_offset );
   }
@@ -2973,7 +2929,7 @@ static FT_Error  Load_ChainContextSubst3(
 
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
-	 ( error = _HB_OPEN_Load_Coverage( &i[ni], stream ) ) != FT_Err_Ok )
+	 ( error = _HB_OPEN_Load_Coverage( &i[ni], stream ) ) != HB_Err_Ok )
       goto Fail3;
     (void)FILE_Seek( cur_offset );
   }
@@ -3006,7 +2962,7 @@ static FT_Error  Load_ChainContextSubst3(
 
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
-	 ( error = _HB_OPEN_Load_Coverage( &l[nl], stream ) ) != FT_Err_Ok )
+	 ( error = _HB_OPEN_Load_Coverage( &l[nl], stream ) ) != HB_Err_Ok )
       goto Fail2;
     (void)FILE_Seek( cur_offset );
   }
@@ -3039,7 +2995,7 @@ static FT_Error  Load_ChainContextSubst3(
 
   FORGET_Frame();
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   FREE( slr );
@@ -3112,10 +3068,10 @@ static void  Free_ChainContextSubst3( HB_ChainContextSubstFormat3*  ccsf3,
 
 /* ChainContextSubst */
 
-static FT_Error  Load_ChainContextSubst( HB_GSUB_SubTable* st,
+static HB_Error  Load_ChainContextSubst( HB_GSUB_SubTable* st,
 					 FT_Stream         stream )
 {
-  FT_Error error;
+  HB_Error error;
   HB_ChainContextSubst*  ccs = &st->chain;
 
   if ( ACCESS_Frame( 2L ) )
@@ -3125,22 +3081,14 @@ static FT_Error  Load_ChainContextSubst( HB_GSUB_SubTable* st,
 
   FORGET_Frame();
 
-  switch ( ccs->SubstFormat )
-  {
-  case 1:
-    return Load_ChainContextSubst1( &ccs->ccsf.ccsf1, stream );
-
-  case 2:
-    return Load_ChainContextSubst2( &ccs->ccsf.ccsf2, stream );
-
-  case 3:
-    return Load_ChainContextSubst3( &ccs->ccsf.ccsf3, stream );
-
-  default:
-    return HB_Err_Invalid_GSUB_SubTable_Format;
+  switch ( ccs->SubstFormat ) {
+    case 1:  return Load_ChainContextSubst1( &ccs->ccsf.ccsf1, stream );
+    case 2:  return Load_ChainContextSubst2( &ccs->ccsf.ccsf2, stream );
+    case 3:  return Load_ChainContextSubst3( &ccs->ccsf.ccsf3, stream );
+    default: return _hb_err(HB_Err_Invalid_GSUB_SubTable_Format);
   }
 
-  return FT_Err_Ok;               /* never reached */
+  return HB_Err_Ok;               /* never reached */
 }
 
 
@@ -3149,24 +3097,16 @@ static void  Free_ChainContextSubst( HB_GSUB_SubTable* st,
 {
   HB_ChainContextSubst*  ccs = &st->chain;
 
-  switch ( ccs->SubstFormat )
-  {
-  case 1:
-    Free_ChainContextSubst1( &ccs->ccsf.ccsf1, memory );
-    break;
-
-  case 2:
-    Free_ChainContextSubst2( &ccs->ccsf.ccsf2, memory );
-    break;
-
-  case 3:
-    Free_ChainContextSubst3( &ccs->ccsf.ccsf3, memory );
-    break;
+  switch ( ccs->SubstFormat ) {
+    case 1:  Free_ChainContextSubst1( &ccs->ccsf.ccsf1, memory ); break;
+    case 2:  Free_ChainContextSubst2( &ccs->ccsf.ccsf2, memory ); break;
+    case 3:  Free_ChainContextSubst3( &ccs->ccsf.ccsf3, memory ); break;
+    default:							  break;
   }
 }
 
 
-static FT_Error  Lookup_ChainContextSubst1( HB_GSUBHeader*               gsub,
+static HB_Error  Lookup_ChainContextSubst1( HB_GSUBHeader*               gsub,
 					    HB_ChainContextSubstFormat1* ccsf1,
 					    HB_Buffer                    buffer,
 					    FT_UShort                     flags,
@@ -3176,7 +3116,7 @@ static FT_Error  Lookup_ChainContextSubst1( HB_GSUBHeader*               gsub,
   FT_UShort          index, property;
   FT_UShort          i, j, k, num_csr;
   FT_UShort          bgc, igc, lgc;
-  FT_Error           error;
+  HB_Error           error;
 
   HB_ChainSubRule*  csr;
   HB_ChainSubRule   curr_csr;
@@ -3293,7 +3233,7 @@ static FT_Error  Lookup_ChainContextSubst1( HB_GSUBHeader*               gsub,
 }
 
 
-static FT_Error  Lookup_ChainContextSubst2( HB_GSUBHeader*               gsub,
+static HB_Error  Lookup_ChainContextSubst2( HB_GSUBHeader*               gsub,
 					    HB_ChainContextSubstFormat2* ccsf2,
 					    HB_Buffer                    buffer,
 					    FT_UShort                     flags,
@@ -3302,7 +3242,7 @@ static FT_Error  Lookup_ChainContextSubst2( HB_GSUBHeader*               gsub,
 {
   FT_UShort              index, property;
   FT_Memory              memory;
-  FT_Error               error;
+  HB_Error               error;
   FT_UShort              i, j, k;
   FT_UShort              bgc, igc, lgc;
   FT_UShort              known_backtrack_classes,
@@ -3356,7 +3296,7 @@ static FT_Error  Lookup_ChainContextSubst2( HB_GSUBHeader*               gsub,
   cscs = &ccsf2->ChainSubClassSet[input_classes[0]];
   if ( !cscs )
   {
-    error = HB_Err_Invalid_GSUB_SubTable;
+    error = _hb_err(HB_Err_Invalid_GSUB_SubTable);
     goto End1;
   }
 
@@ -3495,7 +3435,7 @@ End3:
 }
 
 
-static FT_Error  Lookup_ChainContextSubst3( HB_GSUBHeader*               gsub,
+static HB_Error  Lookup_ChainContextSubst3( HB_GSUBHeader*               gsub,
 					    HB_ChainContextSubstFormat3* ccsf3,
 					    HB_Buffer                    buffer,
 					    FT_UShort                     flags,
@@ -3504,7 +3444,7 @@ static FT_Error  Lookup_ChainContextSubst3( HB_GSUBHeader*               gsub,
 {
   FT_UShort        index, i, j, property;
   FT_UShort        bgc, igc, lgc;
-  FT_Error         error;
+  HB_Error         error;
 
   HB_Coverage*    bc;
   HB_Coverage*    ic;
@@ -3604,7 +3544,7 @@ static FT_Error  Lookup_ChainContextSubst3( HB_GSUBHeader*               gsub,
 }
 
 
-static FT_Error  Lookup_ChainContextSubst( HB_GSUBHeader*    gsub,
+static HB_Error  Lookup_ChainContextSubst( HB_GSUBHeader*    gsub,
 					   HB_GSUB_SubTable* st,
 					   HB_Buffer         buffer,
 					   FT_UShort          flags,
@@ -3613,35 +3553,19 @@ static FT_Error  Lookup_ChainContextSubst( HB_GSUBHeader*    gsub,
 {
   HB_ChainContextSubst*  ccs = &st->chain;
 
-  switch ( ccs->SubstFormat )
-  {
-  case 1:
-    return Lookup_ChainContextSubst1( gsub, &ccs->ccsf.ccsf1, buffer,
-				      flags, context_length,
-				      nesting_level );
-
-  case 2:
-    return Lookup_ChainContextSubst2( gsub, &ccs->ccsf.ccsf2, buffer,
-				      flags, context_length,
-				      nesting_level );
-
-  case 3:
-    return Lookup_ChainContextSubst3( gsub, &ccs->ccsf.ccsf3, buffer,
-				      flags, context_length,
-				      nesting_level );
-
-  default:
-    return HB_Err_Invalid_GSUB_SubTable_Format;
+  switch ( ccs->SubstFormat ) {
+    case 1:  return Lookup_ChainContextSubst1( gsub, &ccs->ccsf.ccsf1, buffer, flags, context_length, nesting_level );
+    case 2:  return Lookup_ChainContextSubst2( gsub, &ccs->ccsf.ccsf2, buffer, flags, context_length, nesting_level );
+    case 3:  return Lookup_ChainContextSubst3( gsub, &ccs->ccsf.ccsf3, buffer, flags, context_length, nesting_level );
+    default: return _hb_err(HB_Err_Invalid_GSUB_SubTable_Format);
   }
-
-  return FT_Err_Ok;               /* never reached */
 }
 
 
-static FT_Error  Load_ReverseChainContextSubst( HB_GSUB_SubTable* st,
+static HB_Error  Load_ReverseChainContextSubst( HB_GSUB_SubTable* st,
 					        FT_Stream         stream )
 {
-  FT_Error error;
+  HB_Error error;
   FT_Memory memory = stream->memory;
   HB_ReverseChainContextSubst*  rccs = &st->reverse;
 
@@ -3663,7 +3587,7 @@ static FT_Error  Load_ReverseChainContextSubst( HB_GSUB_SubTable* st,
   rccs->SubstFormat = GET_UShort();
 
   if ( rccs->SubstFormat != 1 )
-    return HB_Err_Invalid_GSUB_SubTable_Format;
+    return _hb_err(HB_Err_Invalid_GSUB_SubTable_Format);
 
   FORGET_Frame();
 
@@ -3676,7 +3600,7 @@ static FT_Error  Load_ReverseChainContextSubst( HB_GSUB_SubTable* st,
 
   cur_offset = FILE_Pos();
   if ( FILE_Seek( new_offset ) ||
-       ( error = _HB_OPEN_Load_Coverage( &rccs->Coverage, stream ) ) != FT_Err_Ok )
+       ( error = _HB_OPEN_Load_Coverage( &rccs->Coverage, stream ) ) != HB_Err_Ok )
     return error;
   (void)FILE_Seek( cur_offset );
 
@@ -3709,7 +3633,7 @@ static FT_Error  Load_ReverseChainContextSubst( HB_GSUB_SubTable* st,
 
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
-	 ( error = _HB_OPEN_Load_Coverage( &b[nb], stream ) ) != FT_Err_Ok )
+	 ( error = _HB_OPEN_Load_Coverage( &b[nb], stream ) ) != HB_Err_Ok )
       goto Fail3;
     (void)FILE_Seek( cur_offset );
   }
@@ -3743,7 +3667,7 @@ static FT_Error  Load_ReverseChainContextSubst( HB_GSUB_SubTable* st,
 
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
-	 ( error = _HB_OPEN_Load_Coverage( &l[nl], stream ) ) != FT_Err_Ok )
+	 ( error = _HB_OPEN_Load_Coverage( &l[nl], stream ) ) != HB_Err_Ok )
       goto Fail2;
     (void)FILE_Seek( cur_offset );
   }
@@ -3773,7 +3697,7 @@ static FT_Error  Load_ReverseChainContextSubst( HB_GSUB_SubTable* st,
 
   FORGET_Frame();
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   FREE( sub );
@@ -3832,24 +3756,28 @@ static void  Free_ReverseChainContextSubst( HB_GSUB_SubTable* st,
 }
 
 
-static FT_Error  Lookup_ReverseChainContextSubst( HB_GSUBHeader*    gsub,
+static HB_Error  Lookup_ReverseChainContextSubst( HB_GSUBHeader*    gsub,
 						  HB_GSUB_SubTable* st,
 						  HB_Buffer         buffer,
-						  FT_UShort          flags,
-      /* note different signature here: */	  FT_ULong           string_index )
+						  FT_UShort         flags,
+						  FT_UShort         context_length,
+						  int               nesting_level )
 {
   FT_UShort        index, input_index, i, j, property;
   FT_UShort        bgc, lgc;
-  FT_Error         error;
+  HB_Error         error;
 
   HB_ReverseChainContextSubst*  rccs = &st->reverse;
   HB_Coverage*    bc;
   HB_Coverage*    lc;
   HB_GDEFHeader*  gdef;
 
+  if ( nesting_level != 1 || context_length != 0xFFFF )
+    return HB_Err_Not_Covered;
+
   gdef = gsub->gdef;
 
-  if ( CHECK_Property( gdef, IN_ITEM( string_index ), flags, &property ) )
+  if ( CHECK_Property( gdef, IN_CURITEM(), flags, &property ) )
     return error;
 
   bgc = rccs->BacktrackGlyphCount;
@@ -3857,7 +3785,7 @@ static FT_Error  Lookup_ReverseChainContextSubst( HB_GSUBHeader*    gsub,
 
   /* check whether context is too long; it is a first guess only */
 
-  if ( bgc > string_index || string_index + 1 + lgc > buffer->in_length )
+  if ( bgc > buffer->in_pos || buffer->in_pos + 1 + lgc > buffer->in_length )
     return HB_Err_Not_Covered;
 
   if ( bgc )
@@ -3867,7 +3795,7 @@ static FT_Error  Lookup_ReverseChainContextSubst( HB_GSUBHeader*    gsub,
 
     bc       = rccs->BacktrackCoverage;
 
-    for ( i = 0, j = string_index - 1; i < bgc; i++, j-- )
+    for ( i = 0, j = buffer->in_pos - 1; i < bgc; i++, j-- )
     {
       while ( CHECK_Property( gdef, IN_ITEM( j ), flags, &property ) )
       {
@@ -3885,20 +3813,15 @@ static FT_Error  Lookup_ReverseChainContextSubst( HB_GSUBHeader*    gsub,
     }
   }
 
-  j = string_index;
+  j = buffer->in_pos;
 
   error = _HB_OPEN_Coverage_Index( &rccs->Coverage, IN_GLYPH( j ), &input_index );
   if ( error )
       return error;
 
-  /* we are starting for lookahead glyphs right after the last context
-     glyph                                                             */
-
-  j += 1;
-
   lc       = rccs->LookaheadCoverage;
 
-  for ( i = 0; i < lgc; i++, j++ )
+  for ( i = 0, j = buffer->in_pos + 1; i < lgc; i++, j++ )
   {
     while ( CHECK_Property( gdef, IN_ITEM( j ), flags, &property ) )
     {
@@ -3915,7 +3838,8 @@ static FT_Error  Lookup_ReverseChainContextSubst( HB_GSUBHeader*    gsub,
       return error;
   }
 
-  IN_GLYPH( string_index ) = rccs->Substitute[input_index];
+  IN_CURGLYPH() = rccs->Substitute[input_index];
+  buffer->in_pos--; /* Reverse! */
 
   return error;
 }
@@ -3928,7 +3852,7 @@ static FT_Error  Lookup_ReverseChainContextSubst( HB_GSUBHeader*    gsub,
 
 
 
-FT_Error  HB_GSUB_Select_Script( HB_GSUBHeader*  gsub,
+HB_Error  HB_GSUB_Select_Script( HB_GSUBHeader*  gsub,
 				 FT_ULong         script_tag,
 				 FT_UShort*       script_index )
 {
@@ -3939,7 +3863,7 @@ FT_Error  HB_GSUB_Select_Script( HB_GSUBHeader*  gsub,
 
 
   if ( !gsub || !script_index )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   sl = &gsub->ScriptList;
   sr = sl->ScriptRecord;
@@ -3949,7 +3873,7 @@ FT_Error  HB_GSUB_Select_Script( HB_GSUBHeader*  gsub,
     {
       *script_index = n;
 
-      return FT_Err_Ok;
+      return HB_Err_Ok;
     }
 
   return HB_Err_Not_Covered;
@@ -3957,7 +3881,7 @@ FT_Error  HB_GSUB_Select_Script( HB_GSUBHeader*  gsub,
 
 
 
-FT_Error  HB_GSUB_Select_Language( HB_GSUBHeader*  gsub,
+HB_Error  HB_GSUB_Select_Language( HB_GSUBHeader*  gsub,
 				   FT_ULong         language_tag,
 				   FT_UShort        script_index,
 				   FT_UShort*       language_index,
@@ -3972,13 +3896,13 @@ FT_Error  HB_GSUB_Select_Language( HB_GSUBHeader*  gsub,
 
 
   if ( !gsub || !language_index || !req_feature_index )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   sl = &gsub->ScriptList;
   sr = sl->ScriptRecord;
 
   if ( script_index >= sl->ScriptCount )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   s   = &sr[script_index].Script;
   lsr = s->LangSysRecord;
@@ -3989,7 +3913,7 @@ FT_Error  HB_GSUB_Select_Language( HB_GSUBHeader*  gsub,
       *language_index = n;
       *req_feature_index = lsr[n].LangSys.ReqFeatureIndex;
 
-      return FT_Err_Ok;
+      return HB_Err_Ok;
     }
 
   return HB_Err_Not_Covered;
@@ -4000,7 +3924,7 @@ FT_Error  HB_GSUB_Select_Language( HB_GSUBHeader*  gsub,
    default language (DefaultLangSys)                              */
 
 
-FT_Error  HB_GSUB_Select_Feature( HB_GSUBHeader*  gsub,
+HB_Error  HB_GSUB_Select_Feature( HB_GSUBHeader*  gsub,
 				  FT_ULong         feature_tag,
 				  FT_UShort        script_index,
 				  FT_UShort        language_index,
@@ -4020,7 +3944,7 @@ FT_Error  HB_GSUB_Select_Feature( HB_GSUBHeader*  gsub,
 
 
   if ( !gsub || !feature_index )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   sl = &gsub->ScriptList;
   sr = sl->ScriptRecord;
@@ -4029,7 +3953,7 @@ FT_Error  HB_GSUB_Select_Feature( HB_GSUBHeader*  gsub,
   fr = fl->FeatureRecord;
 
   if ( script_index >= sl->ScriptCount )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   s   = &sr[script_index].Script;
   lsr = s->LangSysRecord;
@@ -4039,7 +3963,7 @@ FT_Error  HB_GSUB_Select_Feature( HB_GSUBHeader*  gsub,
   else
   {
     if ( language_index >= s->LangSysCount )
-      return FT_Err_Invalid_Argument;
+      return HB_Err_Invalid_Argument;
 
     ls = &lsr[language_index].LangSys;
   }
@@ -4049,13 +3973,13 @@ FT_Error  HB_GSUB_Select_Feature( HB_GSUBHeader*  gsub,
   for ( n = 0; n < ls->FeatureCount; n++ )
   {
     if ( fi[n] >= fl->FeatureCount )
-      return HB_Err_Invalid_GSUB_SubTable_Format;
+      return _hb_err(HB_Err_Invalid_GSUB_SubTable_Format);
 
     if ( feature_tag == fr[fi[n]].FeatureTag )
     {
       *feature_index = fi[n];
 
-      return FT_Err_Ok;
+      return HB_Err_Ok;
     }
   }
 
@@ -4066,11 +3990,11 @@ FT_Error  HB_GSUB_Select_Feature( HB_GSUBHeader*  gsub,
 /* The next three functions return a null-terminated list */
 
 
-FT_Error  HB_GSUB_Query_Scripts( HB_GSUBHeader*  gsub,
+HB_Error  HB_GSUB_Query_Scripts( HB_GSUBHeader*  gsub,
 				 FT_ULong**       script_tag_list )
 {
   FT_UShort          n;
-  FT_Error           error;
+  HB_Error           error;
   FT_Memory          memory;
   FT_ULong*          stl;
 
@@ -4079,7 +4003,7 @@ FT_Error  HB_GSUB_Query_Scripts( HB_GSUBHeader*  gsub,
 
 
   if ( !gsub || !script_tag_list )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   memory = gsub->memory;
 
@@ -4095,17 +4019,17 @@ FT_Error  HB_GSUB_Query_Scripts( HB_GSUBHeader*  gsub,
 
   *script_tag_list = stl;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
 
-FT_Error  HB_GSUB_Query_Languages( HB_GSUBHeader*  gsub,
+HB_Error  HB_GSUB_Query_Languages( HB_GSUBHeader*  gsub,
 				   FT_UShort        script_index,
 				   FT_ULong**       language_tag_list )
 {
   FT_UShort           n;
-  FT_Error            error;
+  HB_Error            error;
   FT_Memory           memory;
   FT_ULong*           ltl;
 
@@ -4116,7 +4040,7 @@ FT_Error  HB_GSUB_Query_Languages( HB_GSUBHeader*  gsub,
 
 
   if ( !gsub || !language_tag_list )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   memory = gsub->memory;
 
@@ -4124,7 +4048,7 @@ FT_Error  HB_GSUB_Query_Languages( HB_GSUBHeader*  gsub,
   sr = sl->ScriptRecord;
 
   if ( script_index >= sl->ScriptCount )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   s   = &sr[script_index].Script;
   lsr = s->LangSysRecord;
@@ -4138,7 +4062,7 @@ FT_Error  HB_GSUB_Query_Languages( HB_GSUBHeader*  gsub,
 
   *language_tag_list = ltl;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
@@ -4146,13 +4070,13 @@ FT_Error  HB_GSUB_Query_Languages( HB_GSUBHeader*  gsub,
    default language (DefaultLangSys)                              */
 
 
-FT_Error  HB_GSUB_Query_Features( HB_GSUBHeader*  gsub,
+HB_Error  HB_GSUB_Query_Features( HB_GSUBHeader*  gsub,
 				  FT_UShort        script_index,
 				  FT_UShort        language_index,
 				  FT_ULong**       feature_tag_list )
 {
   FT_UShort           n;
-  FT_Error            error;
+  HB_Error            error;
   FT_Memory           memory;
   FT_ULong*           ftl;
 
@@ -4168,7 +4092,7 @@ FT_Error  HB_GSUB_Query_Features( HB_GSUBHeader*  gsub,
 
 
   if ( !gsub || !feature_tag_list )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   memory = gsub->memory;
 
@@ -4179,7 +4103,7 @@ FT_Error  HB_GSUB_Query_Features( HB_GSUBHeader*  gsub,
   fr = fl->FeatureRecord;
 
   if ( script_index >= sl->ScriptCount )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   s   = &sr[script_index].Script;
   lsr = s->LangSysRecord;
@@ -4189,7 +4113,7 @@ FT_Error  HB_GSUB_Query_Features( HB_GSUBHeader*  gsub,
   else
   {
     if ( language_index >= s->LangSysCount )
-      return FT_Err_Invalid_Argument;
+      return HB_Err_Invalid_Argument;
 
     ls = &lsr[language_index].LangSys;
   }
@@ -4204,7 +4128,7 @@ FT_Error  HB_GSUB_Query_Features( HB_GSUBHeader*  gsub,
     if ( fi[n] >= fl->FeatureCount )
     {
       FREE( ftl );
-      return HB_Err_Invalid_GSUB_SubTable_Format;
+      return _hb_err(HB_Err_Invalid_GSUB_SubTable_Format);
     }
     ftl[n] = fr[fi[n]].FeatureTag;
   }
@@ -4212,51 +4136,27 @@ FT_Error  HB_GSUB_Query_Features( HB_GSUBHeader*  gsub,
 
   *feature_tag_list = ftl;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
-typedef FT_Error  (*Lookup_Subst_Func_Type)( HB_GSUBHeader*    gsub,
-					     HB_GSUB_SubTable* st,
-					     HB_Buffer         buffer,
-					     FT_UShort          flags,
-					     FT_UShort          context_length,
-					     int                nesting_level );
-static const Lookup_Subst_Func_Type Lookup_Subst_Call_Table[] = {
-  Lookup_DefaultSubst,
-  Lookup_SingleSubst,		/* HB_GSUB_LOOKUP_SINGLE        1 */
-  Lookup_MultipleSubst,		/* HB_GSUB_LOOKUP_MULTIPLE      2 */
-  Lookup_AlternateSubst,	/* HB_GSUB_LOOKUP_ALTERNATE     3 */
-  Lookup_LigatureSubst,		/* HB_GSUB_LOOKUP_LIGATURE      4 */
-  Lookup_ContextSubst,		/* HB_GSUB_LOOKUP_CONTEXT       5 */
-  Lookup_ChainContextSubst,	/* HB_GSUB_LOOKUP_CHAIN         6 */
-  Lookup_DefaultSubst		/* HB_GSUB_LOOKUP_EXTENSION     7 */
-};
-/* Note that the following lookup does not belong to the table above:
- * Lookup_ReverseChainContextSubst,	 HB_GSUB_LOOKUP_REVERSE_CHAIN 8
- * because it's invalid to happen where this table is used.  It's
- * signature is different too...
- */
-
-/* Do an individual subtable lookup.  Returns FT_Err_Ok if substitution
+/* Do an individual subtable lookup.  Returns HB_Err_Ok if substitution
    has been done, or HB_Err_Not_Covered if not.                        */
-static FT_Error  GSUB_Do_Glyph_Lookup( HB_GSUBHeader* gsub,
-				       FT_UShort       lookup_index,
+static HB_Error  GSUB_Do_Glyph_Lookup( HB_GSUBHeader* gsub,
+				       FT_UShort      lookup_index,
 				       HB_Buffer      buffer,
-				       FT_UShort       context_length,
-				       int             nesting_level )
+				       FT_UShort      context_length,
+				       int            nesting_level )
 {
-  FT_Error               error = HB_Err_Not_Covered;
+  HB_Error               error = HB_Err_Not_Covered;
   FT_UShort              i, flags, lookup_count;
   HB_Lookup*             lo;
   int                    lookup_type;
-  Lookup_Subst_Func_Type Func;
-
 
   nesting_level++;
 
   if ( nesting_level > HB_MAX_NESTING_LEVEL )
-    return HB_Err_Too_Many_Nested_Contexts;
+    return _hb_err(HB_Err_Too_Many_Nested_Contexts);
 
   lookup_count = gsub->LookupList.LookupCount;
   if (lookup_index >= lookup_count)
@@ -4266,21 +4166,33 @@ static FT_Error  GSUB_Do_Glyph_Lookup( HB_GSUBHeader* gsub,
   flags = lo->LookupFlag;
   lookup_type = lo->LookupType;
 
-  if (lookup_type >= ARRAY_LEN (Lookup_Subst_Call_Table))
-    lookup_type = 0;
-  Func = Lookup_Subst_Call_Table[lookup_type];
-
   for ( i = 0; i < lo->SubTableCount; i++ )
   {
-    error = Func ( gsub,
-		   &lo->SubTable[i].st.gsub,
-		   buffer,
-		   flags, context_length,
-		   nesting_level );
+    HB_GSUB_SubTable *st = &lo->SubTable[i].st.gsub;
+
+    switch (lookup_type) {
+      case HB_GSUB_LOOKUP_SINGLE:
+	error = Lookup_SingleSubst		( gsub, st, buffer, flags, context_length, nesting_level ); break;
+      case HB_GSUB_LOOKUP_MULTIPLE:
+	error = Lookup_MultipleSubst		( gsub, st, buffer, flags, context_length, nesting_level ); break;
+      case HB_GSUB_LOOKUP_ALTERNATE:
+	error = Lookup_AlternateSubst		( gsub, st, buffer, flags, context_length, nesting_level ); break;
+      case HB_GSUB_LOOKUP_LIGATURE:
+	error = Lookup_LigatureSubst		( gsub, st, buffer, flags, context_length, nesting_level ); break;
+      case HB_GSUB_LOOKUP_CONTEXT:
+	error = Lookup_ContextSubst		( gsub, st, buffer, flags, context_length, nesting_level ); break;
+      case HB_GSUB_LOOKUP_CHAIN:
+	error = Lookup_ChainContextSubst	( gsub, st, buffer, flags, context_length, nesting_level ); break;
+    /*case HB_GSUB_LOOKUP_EXTENSION:
+	error = Lookup_ExtensionSubst		( gsub, st, buffer, flags, context_length, nesting_level ); break;*/
+      case HB_GSUB_LOOKUP_REVERSE_CHAIN:
+	error = Lookup_ReverseChainContextSubst	( gsub, st, buffer, flags, context_length, nesting_level ); break;
+      default:
+	error = HB_Err_Not_Covered;
+    };
 
     /* Check whether we have a successful substitution or an error other
        than HB_Err_Not_Covered                                          */
-
     if ( error != HB_Err_Not_Covered )
       return error;
   }
@@ -4289,163 +4201,135 @@ static FT_Error  GSUB_Do_Glyph_Lookup( HB_GSUBHeader* gsub,
 }
 
 
-static FT_Error  Load_DefaultSubst( HB_GSUB_SubTable* st,
-				    FT_Stream         stream )
-{
-  FT_UNUSED(st);
-  FT_UNUSED(stream);
-
-  return HB_Err_Invalid_GSUB_SubTable_Format;
-}
-
-typedef FT_Error  (*Load_Subst_Func_Type)( HB_GSUB_SubTable* st,
-					   FT_Stream         stream );
-static const Load_Subst_Func_Type Load_Subst_Call_Table[] = {
-  Load_DefaultSubst,
-  Load_SingleSubst,		/* HB_GSUB_LOOKUP_SINGLE        1 */
-  Load_MultipleSubst,		/* HB_GSUB_LOOKUP_MULTIPLE      2 */
-  Load_AlternateSubst,		/* HB_GSUB_LOOKUP_ALTERNATE     3 */
-  Load_LigatureSubst,		/* HB_GSUB_LOOKUP_LIGATURE      4 */
-  Load_ContextSubst,		/* HB_GSUB_LOOKUP_CONTEXT       5 */
-  Load_ChainContextSubst,	/* HB_GSUB_LOOKUP_CHAIN         6 */
-  Load_DefaultSubst,		/* HB_GSUB_LOOKUP_EXTENSION     7 */
-  Load_ReverseChainContextSubst /* HB_GSUB_LOOKUP_REVERSE_CHAIN 8 */
-};
-
-FT_Error  _HB_GSUB_Load_SubTable( HB_GSUB_SubTable*  st,
+HB_Error  _HB_GSUB_Load_SubTable( HB_GSUB_SubTable*  st,
 				  FT_Stream     stream,
 				  FT_UShort     lookup_type )
 {
-  Load_Subst_Func_Type Func;
-
-  if (lookup_type >= ARRAY_LEN (Load_Subst_Call_Table))
-    lookup_type = 0;
-
-  Func = Load_Subst_Call_Table[lookup_type];
-
-  return Func ( st, stream );
-}
-
-
-static void  Free_DefaultSubst( HB_GSUB_SubTable* st,
-				FT_Memory         memory )
-{
-  FT_UNUSED(st);
-  FT_UNUSED(memory);
+  switch (lookup_type) {
+    case HB_GSUB_LOOKUP_SINGLE:		return Load_SingleSubst			( st, stream );
+    case HB_GSUB_LOOKUP_MULTIPLE:	return Load_MultipleSubst		( st, stream );
+    case HB_GSUB_LOOKUP_ALTERNATE:	return Load_AlternateSubst		( st, stream );
+    case HB_GSUB_LOOKUP_LIGATURE:	return Load_LigatureSubst		( st, stream );
+    case HB_GSUB_LOOKUP_CONTEXT:	return Load_ContextSubst		( st, stream );
+    case HB_GSUB_LOOKUP_CHAIN:		return Load_ChainContextSubst		( st, stream );
+  /*case HB_GSUB_LOOKUP_EXTENSION:	return Load_ExtensionSubst		( st, stream );*/
+    case HB_GSUB_LOOKUP_REVERSE_CHAIN:	return Load_ReverseChainContextSubst	( st, stream );
+    default:				return _hb_err(HB_Err_Invalid_GSUB_SubTable_Format);
+  };
 }
 
-typedef void  (*Free_Subst_Func_Type)( HB_GSUB_SubTable* st,
-				       FT_Memory         memory );
-static const Free_Subst_Func_Type Free_Subst_Call_Table[] = {
-  Free_DefaultSubst,
-  Free_SingleSubst,		/* HB_GSUB_LOOKUP_SINGLE        1 */
-  Free_MultipleSubst,		/* HB_GSUB_LOOKUP_MULTIPLE      2 */
-  Free_AlternateSubst,		/* HB_GSUB_LOOKUP_ALTERNATE     3 */
-  Free_LigatureSubst,		/* HB_GSUB_LOOKUP_LIGATURE      4 */
-  Free_ContextSubst,		/* HB_GSUB_LOOKUP_CONTEXT       5 */
-  Free_ChainContextSubst,	/* HB_GSUB_LOOKUP_CHAIN         6 */
-  Free_DefaultSubst,		/* HB_GSUB_LOOKUP_EXTENSION     7 */
-  Free_ReverseChainContextSubst /* HB_GSUB_LOOKUP_REVERSE_CHAIN 8 */
-};
 
 void  _HB_GSUB_Free_SubTable( HB_GSUB_SubTable*  st,
 			      FT_Memory     memory,
 			      FT_UShort     lookup_type )
 {
-  Free_Subst_Func_Type Func;
-
-  if (lookup_type >= ARRAY_LEN (Free_Subst_Call_Table))
-    lookup_type = 0;
-
-  Func = Free_Subst_Call_Table[lookup_type];
-
-  Func ( st, memory );
+  switch ( lookup_type ) {
+    case HB_GSUB_LOOKUP_SINGLE:		Free_SingleSubst		( st, memory ); return;
+    case HB_GSUB_LOOKUP_MULTIPLE:	Free_MultipleSubst		( st, memory ); return;
+    case HB_GSUB_LOOKUP_ALTERNATE:	Free_AlternateSubst		( st, memory ); return;
+    case HB_GSUB_LOOKUP_LIGATURE:	Free_LigatureSubst		( st, memory ); return;
+    case HB_GSUB_LOOKUP_CONTEXT:	Free_ContextSubst		( st, memory ); return;
+    case HB_GSUB_LOOKUP_CHAIN:		Free_ChainContextSubst		( st, memory ); return;
+  /*case HB_GSUB_LOOKUP_EXTENSION:	Free_ExtensionSubst		( st, memory ); return;*/
+    case HB_GSUB_LOOKUP_REVERSE_CHAIN:	Free_ReverseChainContextSubst	( st, memory ); return;
+    default:										return;
+  };
 }
 
 
 
 /* apply one lookup to the input string object */
 
-static FT_Error  GSUB_Do_String_Lookup( HB_GSUBHeader*   gsub,
-				   FT_UShort         lookup_index,
-				   HB_Buffer        buffer )
+static HB_Error  GSUB_Do_String_Lookup( HB_GSUBHeader* gsub,
+					FT_UShort      lookup_index,
+					HB_Buffer      buffer )
 {
-  FT_Error  error, retError = HB_Err_Not_Covered;
+  HB_Error  error, retError = HB_Err_Not_Covered;
 
-  FT_UInt*  properties = gsub->LookupList.Properties;
+  FT_UInt*  properties  = gsub->LookupList.Properties;
+  int       lookup_type = gsub->LookupList.Lookup[lookup_index].LookupType;
 
-  int      nesting_level = 0;
-
-
-  while ( buffer->in_pos < buffer->in_length )
-  {
-    if ( ~IN_PROPERTIES( buffer->in_pos ) & properties[lookup_index] )
-    {
-      /* 0xFFFF indicates that we don't have a context length yet */
-      error = GSUB_Do_Glyph_Lookup( gsub, lookup_index, buffer,
-				    0xFFFF, nesting_level );
-      if ( error )
-      {
-	if ( error != HB_Err_Not_Covered )
-	  return error;
-      }
-      else
-	retError = error;
-    }
-    else
-      error = HB_Err_Not_Covered;
+  const int       nesting_level = 0;
+  /* 0xFFFF indicates that we don't have a context length yet */
+  const FT_UShort context_length = 0xFFFF;
 
-    if ( error == HB_Err_Not_Covered )
-      if ( (error = hb_buffer_copy_output_glyph ( buffer ) ) )
-	return error;
-  }
+  switch (lookup_type) {
 
-  return retError;
-}
+    case HB_GSUB_LOOKUP_SINGLE:
+    case HB_GSUB_LOOKUP_MULTIPLE:
+    case HB_GSUB_LOOKUP_ALTERNATE:
+    case HB_GSUB_LOOKUP_LIGATURE:
+    case HB_GSUB_LOOKUP_CONTEXT:
+    case HB_GSUB_LOOKUP_CHAIN:
+      /* in/out forward substitution (implemented lazy) */
 
+      hb_buffer_clear_output ( buffer );
+      buffer->in_pos = 0;
+      while ( buffer->in_pos < buffer->in_length )
+      {
+	if ( ~IN_PROPERTIES( buffer->in_pos ) & properties[lookup_index] )
+	{
+	  error = GSUB_Do_Glyph_Lookup( gsub, lookup_index, buffer, context_length, nesting_level );
+	  if ( error )
+	  {
+	    if ( error != HB_Err_Not_Covered )
+	      return error;
+	  }
+	  else
+	    retError = error;
+	}
+	else
+	  error = HB_Err_Not_Covered;
 
-static FT_Error  Apply_ReverseChainContextSubst( HB_GSUBHeader*   gsub,
-						 FT_UShort         lookup_index,
-						 HB_Buffer        buffer )
-{
-  FT_UInt*     properties =  gsub->LookupList.Properties;
-  FT_Error     error, retError = HB_Err_Not_Covered;
-  FT_ULong     subtable_Count, string_index;
-  FT_UShort    flags;
-  HB_Lookup*  lo;
+	if ( error == HB_Err_Not_Covered )
+	  if ( COPY_Glyph ( buffer ) )
+	    return error;
+      }
+      /* we shouldn't swap if error occurred.
+       *
+       * also don't swap if nothing changed (ie HB_Err_Not_Covered).
+       * shouldn't matter in that case though.
+       */
+      if ( retError == HB_Err_Ok )
+	hb_buffer_swap( buffer );
 
-  if ( buffer->in_length == 0 )
-    return HB_Err_Not_Covered;
+      return retError;
 
-  lo    = &gsub->LookupList.Lookup[lookup_index];
-  flags = lo->LookupFlag;
+    case HB_GSUB_LOOKUP_REVERSE_CHAIN:
+      /* in-place backward substitution */
 
-  for ( subtable_Count = 0; subtable_Count < lo->SubTableCount; subtable_Count++ )
-  {
-    string_index  = buffer->in_length - 1;
-    do
-    {
-      if ( ~IN_PROPERTIES( buffer->in_pos ) & properties[lookup_index] )
+      buffer->in_pos = buffer->in_length - 1;
+      do
+      {
+	if ( ~IN_PROPERTIES( buffer->in_pos ) & properties[lookup_index] )
 	{
-	  error = Lookup_ReverseChainContextSubst( gsub, &lo->SubTable[subtable_Count].st.gsub,
-						   buffer, flags, string_index );
+	  error = GSUB_Do_Glyph_Lookup( gsub, lookup_index, buffer, context_length, nesting_level );
 	  if ( error )
-	    {
-	      if ( error != HB_Err_Not_Covered )
-		return error;
-	    }
+	  {
+	    if ( error != HB_Err_Not_Covered )
+	      return error;
+	  }
 	  else
 	    retError = error;
 	}
-    }
-    while (string_index--);
-  }
+	else
+	  error = HB_Err_Not_Covered;
+
+	if ( error == HB_Err_Not_Covered )
+	  buffer->in_pos--;
+      }
+      while (buffer->in_pos);
 
-  return retError;
+      return retError;
+
+  /*case HB_GSUB_LOOKUP_EXTENSION:*/
+    default:
+      return retError;
+  };
 }
 
 
-FT_Error  HB_GSUB_Add_Feature( HB_GSUBHeader*  gsub,
+HB_Error  HB_GSUB_Add_Feature( HB_GSUBHeader*  gsub,
 			       FT_UShort        feature_index,
 			       FT_UInt          property )
 {
@@ -4461,7 +4345,7 @@ FT_Error  HB_GSUB_Add_Feature( HB_GSUBHeader*  gsub,
   if ( !gsub ||
        feature_index >= gsub->FeatureList.FeatureCount ||
        gsub->FeatureList.ApplyCount == gsub->FeatureList.FeatureCount )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   gsub->FeatureList.ApplyOrder[gsub->FeatureList.ApplyCount++] = feature_index;
 
@@ -4478,12 +4362,12 @@ FT_Error  HB_GSUB_Add_Feature( HB_GSUBHeader*  gsub,
       properties[lookup_index] |= property;
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
 
-FT_Error  HB_GSUB_Clear_Features( HB_GSUBHeader*  gsub )
+HB_Error  HB_GSUB_Clear_Features( HB_GSUBHeader*  gsub )
 {
   FT_UShort i;
 
@@ -4491,7 +4375,7 @@ FT_Error  HB_GSUB_Clear_Features( HB_GSUBHeader*  gsub )
 
 
   if ( !gsub )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   gsub->FeatureList.ApplyCount = 0;
 
@@ -4500,91 +4384,68 @@ FT_Error  HB_GSUB_Clear_Features( HB_GSUBHeader*  gsub )
   for ( i = 0; i < gsub->LookupList.LookupCount; i++ )
     properties[i] = 0;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
 
-FT_Error  HB_GSUB_Register_Alternate_Function( HB_GSUBHeader*  gsub,
+HB_Error  HB_GSUB_Register_Alternate_Function( HB_GSUBHeader*  gsub,
 					       HB_AltFunction  altfunc,
 					       void*            data )
 {
   if ( !gsub )
-    return FT_Err_Invalid_Argument;
+    return HB_Err_Invalid_Argument;
 
   gsub->altfunc = altfunc;
   gsub->data    = data;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
-
-
-FT_Error  HB_GSUB_Apply_String( HB_GSUBHeader*   gsub,
+/* returns error if one happened, otherwise returns HB_Err_Not_Covered if no
+ * feature were applied, or HB_Err_Ok otherwise.
+ */
+HB_Error  HB_GSUB_Apply_String( HB_GSUBHeader*   gsub,
 				HB_Buffer        buffer )
 {
-  FT_Error          error, retError = HB_Err_Not_Covered;
+  HB_Error          error, retError = HB_Err_Not_Covered;
   FT_UShort         i, j, lookup_count;
 
   if ( !gsub ||
-       !buffer || buffer->in_length == 0 || buffer->in_pos >= buffer->in_length )
-    return FT_Err_Invalid_Argument;
+       !buffer)
+    return HB_Err_Invalid_Argument;
+
+  if ( buffer->in_length == 0 )
+    return retError;
 
   lookup_count = gsub->LookupList.LookupCount;
 
   for ( i = 0; i < gsub->FeatureList.ApplyCount; i++)
   {
-    FT_UShort         feature_index;
-    HB_Feature       feature;
-
-    feature_index = gsub->FeatureList.ApplyOrder[i];
-    feature = gsub->FeatureList.FeatureRecord[feature_index].Feature;
+    FT_UShort  feature_index = gsub->FeatureList.ApplyOrder[i];
+    HB_Feature feature = gsub->FeatureList.FeatureRecord[feature_index].Feature;
 
     for ( j = 0; j < feature.LookupListCount; j++ )
     {
-      FT_UShort         lookup_index;
-      HB_Lookup*       lookup;
-      FT_Bool           need_swap;
-
-      lookup_index = feature.LookupListIndex[j];
+      FT_UShort         lookup_index = feature.LookupListIndex[j];
 
       /* Skip nonexistant lookups */
       if (lookup_index >= lookup_count)
        continue;
 
-      lookup = &gsub->LookupList.Lookup[lookup_index];
-
-      if ( lookup->LookupType == HB_GSUB_LOOKUP_REVERSE_CHAIN )
-      {
-	error = Apply_ReverseChainContextSubst( gsub, lookup_index, buffer);
-	need_swap = FALSE; /* We do ReverseChainContextSubst in-place */
-      }
-      else
-      {
-	error = GSUB_Do_String_Lookup( gsub, lookup_index, buffer );
-	need_swap = TRUE;
-      }
-
+      error = GSUB_Do_String_Lookup( gsub, lookup_index, buffer );
       if ( error )
       {
 	if ( error != HB_Err_Not_Covered )
-	  goto End;
+	  return error;
       }
       else
 	retError = error;
-
-      if ( need_swap )
-      {
-	error = hb_buffer_swap( buffer );
-	if ( error )
-	  goto End;
-      }
     }
   }
 
   error = retError;
 
-End:
   return error;
 }
 
diff --git a/pango/opentype/harfbuzz-gsub.h b/pango/opentype/harfbuzz-gsub.h
index 09145bad..3c72981e 100644
--- a/pango/opentype/harfbuzz-gsub.h
+++ b/pango/opentype/harfbuzz-gsub.h
@@ -73,57 +73,57 @@ typedef struct HB_GSUBHeader_   HB_GSUBHeader;
 typedef HB_GSUBHeader*  HB_GSUB;
 
 
-FT_Error  HB_Load_GSUB_Table( FT_Face          face,
+HB_Error  HB_Load_GSUB_Table( FT_Face          face,
 			      HB_GSUBHeader** gsub,
 			      HB_GDEFHeader*  gdef );
 
 
-FT_Error  HB_Done_GSUB_Table( HB_GSUBHeader*  gsub );
+HB_Error  HB_Done_GSUB_Table( HB_GSUBHeader*  gsub );
 
 
-FT_Error  HB_GSUB_Select_Script( HB_GSUBHeader*  gsub,
+HB_Error  HB_GSUB_Select_Script( HB_GSUBHeader*  gsub,
 				 FT_ULong         script_tag,
 				 FT_UShort*       script_index );
 
-FT_Error  HB_GSUB_Select_Language( HB_GSUBHeader*  gsub,
+HB_Error  HB_GSUB_Select_Language( HB_GSUBHeader*  gsub,
 				   FT_ULong         language_tag,
 				   FT_UShort        script_index,
 				   FT_UShort*       language_index,
 				   FT_UShort*       req_feature_index );
 
-FT_Error  HB_GSUB_Select_Feature( HB_GSUBHeader*  gsub,
+HB_Error  HB_GSUB_Select_Feature( HB_GSUBHeader*  gsub,
 				  FT_ULong         feature_tag,
 				  FT_UShort        script_index,
 				  FT_UShort        language_index,
 				  FT_UShort*       feature_index );
 
 
-FT_Error  HB_GSUB_Query_Scripts( HB_GSUBHeader*  gsub,
+HB_Error  HB_GSUB_Query_Scripts( HB_GSUBHeader*  gsub,
 				 FT_ULong**       script_tag_list );
 
-FT_Error  HB_GSUB_Query_Languages( HB_GSUBHeader*  gsub,
+HB_Error  HB_GSUB_Query_Languages( HB_GSUBHeader*  gsub,
 				   FT_UShort        script_index,
 				   FT_ULong**       language_tag_list );
 
-FT_Error  HB_GSUB_Query_Features( HB_GSUBHeader*  gsub,
+HB_Error  HB_GSUB_Query_Features( HB_GSUBHeader*  gsub,
 				  FT_UShort        script_index,
 				  FT_UShort        language_index,
 				  FT_ULong**       feature_tag_list );
 
 
-FT_Error  HB_GSUB_Add_Feature( HB_GSUBHeader*  gsub,
+HB_Error  HB_GSUB_Add_Feature( HB_GSUBHeader*  gsub,
 			       FT_UShort        feature_index,
 			       FT_UInt          property );
 
-FT_Error  HB_GSUB_Clear_Features( HB_GSUBHeader*  gsub );
+HB_Error  HB_GSUB_Clear_Features( HB_GSUBHeader*  gsub );
 
 
-FT_Error  HB_GSUB_Register_Alternate_Function( HB_GSUBHeader*  gsub,
+HB_Error  HB_GSUB_Register_Alternate_Function( HB_GSUBHeader*  gsub,
 					       HB_AltFunction  altfunc,
 					       void*            data );
 
 
-FT_Error  HB_GSUB_Apply_String( HB_GSUBHeader*   gsub,
+HB_Error  HB_GSUB_Apply_String( HB_GSUBHeader*   gsub,
 				HB_Buffer        buffer );
 
 
diff --git a/pango/opentype/harfbuzz-impl.h b/pango/opentype/harfbuzz-impl.h
index f31f5cde..9547b062 100644
--- a/pango/opentype/harfbuzz-impl.h
+++ b/pango/opentype/harfbuzz-impl.h
@@ -63,20 +63,24 @@ FT_BEGIN_HEADER
 #define OUT_GLYPH( pos )       (buffer->out_string[(pos)].gindex)
 #define OUT_ITEM( pos )        (&buffer->out_string[(pos)])
 
-#define CHECK_Property( gdef, index, flags, property )              \
-          ( ( error = _HB_GDEF_Check_Property( (gdef), (index), (flags),     \
-                                      (property) ) ) != FT_Err_Ok )
+#define CHECK_Property( gdef, index, flags, property )					\
+          ( ( error = _HB_GDEF_Check_Property( (gdef), (index), (flags),		\
+                                      (property) ) ) != HB_Err_Ok )
 
 #define ADD_String( buffer, num_in, num_out, glyph_data, component, ligID )             \
-          ( ( error = hb_buffer_add_output_glyphs( (buffer),                           \
+          ( ( error = hb_buffer_add_output_glyphs( (buffer),                            \
 						    (num_in), (num_out),                \
                                                     (glyph_data), (component), (ligID)  \
-                                                  ) ) != FT_Err_Ok )
-#define ADD_Glyph( buffer, glyph_index, component, ligID )             		 	 \
+                                                  ) ) != HB_Err_Ok )
+#define ADD_Glyph( buffer, glyph_index, component, ligID )				\
           ( ( error = hb_buffer_add_output_glyph( (buffer),                             \
-                                                    (glyph_index), (component), (ligID)  \
-                                                  ) ) != FT_Err_Ok )
-
+                                                    (glyph_index), (component), (ligID) \
+                                                  ) ) != HB_Err_Ok )
+#define REPLACE_Glyph( buffer, glyph_index, nesting_level )				\
+          ( ( error = hb_buffer_replace_output_glyph( (buffer), (glyph_index),		\
+						      (nesting_level) == 1 ) ) != HB_Err_Ok )
+#define COPY_Glyph( buffer )								\
+	  ( (error = hb_buffer_copy_output_glyph ( buffer ) ) != HB_Err_Ok )
 
 FT_END_HEADER
 
diff --git a/pango/opentype/harfbuzz-open-private.h b/pango/opentype/harfbuzz-open-private.h
index be265af2..03d232de 100644
--- a/pango/opentype/harfbuzz-open-private.h
+++ b/pango/opentype/harfbuzz-open-private.h
@@ -30,22 +30,22 @@ struct  HB_SubTable_
 };
 
 
-FT_Error  _HB_OPEN_Load_ScriptList( HB_ScriptList*  sl,
+HB_Error  _HB_OPEN_Load_ScriptList( HB_ScriptList*  sl,
 			   FT_Stream     stream );
-FT_Error  _HB_OPEN_Load_FeatureList( HB_FeatureList*  fl,
+HB_Error  _HB_OPEN_Load_FeatureList( HB_FeatureList*  fl,
 			    FT_Stream         input );
-FT_Error  _HB_OPEN_Load_LookupList( HB_LookupList*  ll,
+HB_Error  _HB_OPEN_Load_LookupList( HB_LookupList*  ll,
 			   FT_Stream        input,
 			   HB_Type         type );
 
-FT_Error  _HB_OPEN_Load_Coverage( HB_Coverage*  c,
+HB_Error  _HB_OPEN_Load_Coverage( HB_Coverage*  c,
 			 FT_Stream      input );
-FT_Error  _HB_OPEN_Load_ClassDefinition( HB_ClassDefinition*  cd,
+HB_Error  _HB_OPEN_Load_ClassDefinition( HB_ClassDefinition*  cd,
 				FT_UShort             limit,
 				FT_Stream             input );
-FT_Error  _HB_OPEN_Load_EmptyClassDefinition( HB_ClassDefinition*  cd,
+HB_Error  _HB_OPEN_Load_EmptyClassDefinition( HB_ClassDefinition*  cd,
 				     FT_Stream             input );
-FT_Error  _HB_OPEN_Load_Device( HB_Device*  d,
+HB_Error  _HB_OPEN_Load_Device( HB_Device*  d,
 		       FT_Stream    input );
 
 void  _HB_OPEN_Free_ScriptList( HB_ScriptList*  sl, 
@@ -65,14 +65,14 @@ void  _HB_OPEN_Free_Device( HB_Device*  d,
 
 
 
-FT_Error  _HB_OPEN_Coverage_Index( HB_Coverage*  c,
+HB_Error  _HB_OPEN_Coverage_Index( HB_Coverage*  c,
 			  FT_UShort      glyphID,
 			  FT_UShort*     index );
-FT_Error  _HB_OPEN_Get_Class( HB_ClassDefinition*  cd,
+HB_Error  _HB_OPEN_Get_Class( HB_ClassDefinition*  cd,
 		     FT_UShort             glyphID,
 		     FT_UShort*            class,
 		     FT_UShort*            index );
-FT_Error  _HB_OPEN_Get_Device( HB_Device*  d,
+HB_Error  _HB_OPEN_Get_Device( HB_Device*  d,
 		      FT_UShort    size,
 		      FT_Short*    value );
 
diff --git a/pango/opentype/harfbuzz-open.c b/pango/opentype/harfbuzz-open.c
index fa540401..2aebb5ac 100644
--- a/pango/opentype/harfbuzz-open.c
+++ b/pango/opentype/harfbuzz-open.c
@@ -21,10 +21,10 @@
 
 /* LangSys */
 
-static FT_Error  Load_LangSys( HB_LangSys*  ls,
+static HB_Error  Load_LangSys( HB_LangSys*  ls,
 			       FT_Stream     stream )
 {
-  FT_Error   error;
+  HB_Error   error;
   FT_Memory  memory = stream->memory;
   FT_UShort  n, count;
   FT_UShort* fi;
@@ -57,7 +57,7 @@ static FT_Error  Load_LangSys( HB_LangSys*  ls,
 
   FORGET_Frame();
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
@@ -70,10 +70,10 @@ static void  Free_LangSys( HB_LangSys*  ls,
 
 /* Script */
 
-static FT_Error  Load_Script( HB_Script*  s,
+static HB_Error  Load_Script( HB_Script*  s,
 			      FT_Stream    stream )
 {
-  FT_Error   error;
+  HB_Error   error;
   FT_Memory  memory = stream->memory;
   FT_UShort  n, m, count;
   FT_ULong   cur_offset, new_offset, base_offset;
@@ -95,7 +95,7 @@ static FT_Error  Load_Script( HB_Script*  s,
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
 	 ( error = Load_LangSys( &s->DefaultLangSys,
-				 stream ) ) != FT_Err_Ok )
+				 stream ) ) != HB_Err_Ok )
       return error;
     (void)FILE_Seek( cur_offset );
   }
@@ -144,12 +144,12 @@ static FT_Error  Load_Script( HB_Script*  s,
 
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
-	 ( error = Load_LangSys( &lsr[n].LangSys, stream ) ) != FT_Err_Ok )
+	 ( error = Load_LangSys( &lsr[n].LangSys, stream ) ) != HB_Err_Ok )
       goto Fail1;
     (void)FILE_Seek( cur_offset );
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   for ( m = 0; m < n; m++ )
@@ -188,10 +188,10 @@ static void  Free_Script( HB_Script*  s,
 
 /* ScriptList */
 
-FT_Error  _HB_OPEN_Load_ScriptList( HB_ScriptList*  sl,
+HB_Error  _HB_OPEN_Load_ScriptList( HB_ScriptList*  sl,
 			   FT_Stream        stream )
 {
-  FT_Error   error;
+  HB_Error   error;
   FT_Memory  memory = stream->memory;
 
   FT_UShort          n, script_count;
@@ -233,7 +233,7 @@ FT_Error  _HB_OPEN_Load_ScriptList( HB_ScriptList*  sl,
       goto Fail;
 
     error = Load_Script( &sr[sl->ScriptCount].Script, stream );
-    if ( error == FT_Err_Ok )
+    if ( error == HB_Err_Ok )
       sl->ScriptCount += 1;
     else if ( error != HB_Err_Empty_Script )
       goto Fail;
@@ -247,12 +247,12 @@ FT_Error  _HB_OPEN_Load_ScriptList( HB_ScriptList*  sl,
 #if 0
   if ( sl->ScriptCount == 0 )
   {
-    error = HB_Err_Invalid_SubTable;
+    error = _hb_err(HB_Err_Invalid_SubTable);
     goto Fail;
   }
 #endif
   
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail:
   for ( n = 0; n < sl->ScriptCount; n++ )
@@ -292,10 +292,10 @@ void  _HB_OPEN_Free_ScriptList( HB_ScriptList*  sl,
 
 /* Feature */
 
-static FT_Error  Load_Feature( HB_Feature*  f,
+static HB_Error  Load_Feature( HB_Feature*  f,
 			       FT_Stream     stream )
 {
-  FT_Error   error;
+  HB_Error   error;
   FT_Memory  memory = stream->memory;
 
   FT_UShort   n, count;
@@ -329,7 +329,7 @@ static FT_Error  Load_Feature( HB_Feature*  f,
 
   FORGET_Frame();
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
@@ -342,10 +342,10 @@ static void  Free_Feature( HB_Feature*  f,
 
 /* FeatureList */
 
-FT_Error  _HB_OPEN_Load_FeatureList( HB_FeatureList*  fl,
+HB_Error  _HB_OPEN_Load_FeatureList( HB_FeatureList*  fl,
 			    FT_Stream         stream )
 {
-  FT_Error   error;
+  HB_Error   error;
   FT_Memory  memory = stream->memory;
 
   FT_UShort           n, m, count;
@@ -386,12 +386,12 @@ FT_Error  _HB_OPEN_Load_FeatureList( HB_FeatureList*  fl,
 
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
-	 ( error = Load_Feature( &fr[n].Feature, stream ) ) != FT_Err_Ok )
+	 ( error = Load_Feature( &fr[n].Feature, stream ) ) != HB_Err_Ok )
       goto Fail1;
     (void)FILE_Seek( cur_offset );
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   for ( m = 0; m < n; m++ )
@@ -440,7 +440,7 @@ void  _HB_OPEN_Free_FeatureList( HB_FeatureList*  fl,
 
 /* SubTable */
 
-static FT_Error  Load_SubTable( HB_SubTable*  st,
+static HB_Error  Load_SubTable( HB_SubTable*  st,
 				FT_Stream     stream,
 				HB_Type       table_type,
 				FT_UShort     lookup_type )
@@ -466,11 +466,11 @@ static void  Free_SubTable( HB_SubTable*  st,
 
 /* Lookup */
 
-static FT_Error  Load_Lookup( HB_Lookup*   l,
+static HB_Error  Load_Lookup( HB_Lookup*   l,
 			      FT_Stream     stream,
 			      HB_Type      type )
 {
-  FT_Error   error;
+  HB_Error   error;
   FT_Memory  memory = stream->memory;
 
   FT_UShort      n, m, count;
@@ -530,12 +530,12 @@ static FT_Error  Load_Lookup( HB_Lookup*   l,
 
     if ( FILE_Seek( new_offset ) ||
 	 ( error = Load_SubTable( &st[n], stream,
-				  type, l->LookupType ) ) != FT_Err_Ok )
+				  type, l->LookupType ) ) != HB_Err_Ok )
       goto Fail;
     (void)FILE_Seek( cur_offset );
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail:
   for ( m = 0; m < n; m++ )
@@ -570,11 +570,11 @@ static void  Free_Lookup( HB_Lookup*   l,
 
 /* LookupList */
 
-FT_Error  _HB_OPEN_Load_LookupList( HB_LookupList*  ll,
+HB_Error  _HB_OPEN_Load_LookupList( HB_LookupList*  ll,
 			   FT_Stream        stream,
 			   HB_Type         type )
 {
-  FT_Error   error;
+  HB_Error   error;
   FT_Memory  memory = stream->memory;
 
   FT_UShort    n, m, count;
@@ -612,12 +612,12 @@ FT_Error  _HB_OPEN_Load_LookupList( HB_LookupList*  ll,
 
     cur_offset = FILE_Pos();
     if ( FILE_Seek( new_offset ) ||
-	 ( error = Load_Lookup( &l[n], stream, type ) ) != FT_Err_Ok )
+	 ( error = Load_Lookup( &l[n], stream, type ) ) != HB_Err_Ok )
       goto Fail1;
     (void)FILE_Seek( cur_offset );
   }
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail1:
   FREE( ll->Properties );
@@ -663,10 +663,10 @@ void  _HB_OPEN_Free_LookupList( HB_LookupList*  ll,
 
 /* CoverageFormat1 */
 
-static FT_Error  Load_Coverage1( HB_CoverageFormat1*  cf1,
+static HB_Error  Load_Coverage1( HB_CoverageFormat1*  cf1,
 				 FT_Stream             stream )
 {
-  FT_Error   error;
+  HB_Error   error;
   FT_Memory  memory = stream->memory;
 
   FT_UShort  n, count;
@@ -699,7 +699,7 @@ static FT_Error  Load_Coverage1( HB_CoverageFormat1*  cf1,
 
   FORGET_Frame();
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
@@ -712,10 +712,10 @@ static void  Free_Coverage1( HB_CoverageFormat1*  cf1,
 
 /* CoverageFormat2 */
 
-static FT_Error  Load_Coverage2( HB_CoverageFormat2*  cf2,
+static HB_Error  Load_Coverage2( HB_CoverageFormat2*  cf2,
 				 FT_Stream             stream )
 {
-  FT_Error   error;
+  HB_Error   error;
   FT_Memory  memory = stream->memory;
 
   FT_UShort         n, count;
@@ -751,14 +751,14 @@ static FT_Error  Load_Coverage2( HB_CoverageFormat2*  cf2,
 	 ( rr[n].End - rr[n].Start + (long)rr[n].StartCoverageIndex ) >=
 	   0x10000L )
     {
-      error = HB_Err_Invalid_SubTable;
+      error = _hb_err(HB_Err_Invalid_SubTable);
       goto Fail;
     }
   }
 
   FORGET_Frame();
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail:
   FREE( cf2->RangeRecord );
@@ -773,10 +773,10 @@ static void  Free_Coverage2( HB_CoverageFormat2*  cf2,
 }
 
 
-FT_Error  _HB_OPEN_Load_Coverage( HB_Coverage*  c,
+HB_Error  _HB_OPEN_Load_Coverage( HB_Coverage*  c,
 			 FT_Stream      stream )
 {
-  FT_Error   error;
+  HB_Error   error;
 
   if ( ACCESS_Frame( 2L ) )
     return error;
@@ -787,17 +787,12 @@ FT_Error  _HB_OPEN_Load_Coverage( HB_Coverage*  c,
 
   switch ( c->CoverageFormat )
   {
-  case 1:
-    return Load_Coverage1( &c->cf.cf1, stream );
-
-  case 2:
-    return Load_Coverage2( &c->cf.cf2, stream );
-
-  default:
-    return HB_Err_Invalid_SubTable_Format;
+  case 1:  return Load_Coverage1( &c->cf.cf1, stream );
+  case 2:  return Load_Coverage2( &c->cf.cf2, stream );
+  default: return _hb_err(HB_Err_Invalid_SubTable_Format);
   }
 
-  return FT_Err_Ok;               /* never reached */
+  return HB_Err_Ok;               /* never reached */
 }
 
 
@@ -806,18 +801,14 @@ void  _HB_OPEN_Free_Coverage( HB_Coverage*  c,
 {
   switch ( c->CoverageFormat )
   {
-  case 1:
-    Free_Coverage1( &c->cf.cf1, memory );
-    break;
-
-  case 2:
-    Free_Coverage2( &c->cf.cf2, memory );
-    break;
+  case 1:  Free_Coverage1( &c->cf.cf1, memory ); break;
+  case 2:  Free_Coverage2( &c->cf.cf2, memory ); break;
+  default:					 break;
   }
 }
 
 
-static FT_Error  Coverage_Index1( HB_CoverageFormat1*  cf1,
+static HB_Error  Coverage_Index1( HB_CoverageFormat1*  cf1,
 				  FT_UShort             glyphID,
 				  FT_UShort*            index )
 {
@@ -847,7 +838,7 @@ static FT_Error  Coverage_Index1( HB_CoverageFormat1*  cf1,
     if ( glyphID == array[middle] )
     {
       *index = middle;
-      return FT_Err_Ok;
+      return HB_Err_Ok;
     }
     else if ( glyphID < array[middle] )
     {
@@ -867,7 +858,7 @@ static FT_Error  Coverage_Index1( HB_CoverageFormat1*  cf1,
 }
 
 
-static FT_Error  Coverage_Index2( HB_CoverageFormat2*  cf2,
+static HB_Error  Coverage_Index2( HB_CoverageFormat2*  cf2,
 				  FT_UShort             glyphID,
 				  FT_UShort*            index )
 {
@@ -897,7 +888,7 @@ static FT_Error  Coverage_Index2( HB_CoverageFormat2*  cf2,
     if ( glyphID >= rr[middle].Start && glyphID <= rr[middle].End )
     {
       *index = rr[middle].StartCoverageIndex + glyphID - rr[middle].Start;
-      return FT_Err_Ok;
+      return HB_Err_Ok;
     }
     else if ( glyphID < rr[middle].Start )
     {
@@ -917,23 +908,18 @@ static FT_Error  Coverage_Index2( HB_CoverageFormat2*  cf2,
 }
 
 
-FT_Error  _HB_OPEN_Coverage_Index( HB_Coverage*  c,
+HB_Error  _HB_OPEN_Coverage_Index( HB_Coverage*  c,
 			  FT_UShort      glyphID,
 			  FT_UShort*     index )
 {
   switch ( c->CoverageFormat )
   {
-  case 1:
-    return Coverage_Index1( &c->cf.cf1, glyphID, index );
-
-  case 2:
-    return Coverage_Index2( &c->cf.cf2, glyphID, index );
-
-  default:
-    return HB_Err_Invalid_SubTable_Format;
+  case 1:  return Coverage_Index1( &c->cf.cf1, glyphID, index );
+  case 2:  return Coverage_Index2( &c->cf.cf2, glyphID, index );
+  default: return _hb_err(HB_Err_Invalid_SubTable_Format);
   }
 
-  return FT_Err_Ok;               /* never reached */
+  return HB_Err_Ok;               /* never reached */
 }
 
 
@@ -945,11 +931,11 @@ FT_Error  _HB_OPEN_Coverage_Index( HB_Coverage*  c,
 
 /* ClassDefFormat1 */
 
-static FT_Error  Load_ClassDef1( HB_ClassDefinition*  cd,
+static HB_Error  Load_ClassDef1( HB_ClassDefinition*  cd,
 				 FT_UShort             limit,
 				 FT_Stream             stream )
 {
-  FT_Error   error;
+  HB_Error   error;
   FT_Memory  memory = stream->memory;
 
   FT_UShort             n, count;
@@ -973,7 +959,7 @@ static FT_Error  Load_ClassDef1( HB_ClassDefinition*  cd,
   /* sanity check; we are limited to 16bit integers */
 
   if ( cdf1->StartGlyph + (long)count >= 0x10000L )
-    return HB_Err_Invalid_SubTable;
+    return _hb_err(HB_Err_Invalid_SubTable);
 
   cdf1->ClassValueArray = NULL;
 
@@ -991,7 +977,7 @@ static FT_Error  Load_ClassDef1( HB_ClassDefinition*  cd,
     cva[n] = GET_UShort();
     if ( cva[n] >= limit )
     {
-      error = HB_Err_Invalid_SubTable;
+      error = _hb_err(HB_Err_Invalid_SubTable);
       goto Fail;
     }
     d[cva[n]] = TRUE;
@@ -999,7 +985,7 @@ static FT_Error  Load_ClassDef1( HB_ClassDefinition*  cd,
 
   FORGET_Frame();
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail:
   FREE( cva );
@@ -1017,11 +1003,11 @@ static void  Free_ClassDef1( HB_ClassDefFormat1*  cdf1,
 
 /* ClassDefFormat2 */
 
-static FT_Error  Load_ClassDef2( HB_ClassDefinition*  cd,
+static HB_Error  Load_ClassDef2( HB_ClassDefinition*  cd,
 				 FT_UShort             limit,
 				 FT_Stream             stream )
 {
-  FT_Error   error;
+  HB_Error   error;
   FT_Memory  memory = stream->memory;
 
   FT_UShort              n, count;
@@ -1037,7 +1023,8 @@ static FT_Error  Load_ClassDef2( HB_ClassDefinition*  cd,
   if ( ACCESS_Frame( 2L ) )
     return error;
 
-  count = cdf2->ClassRangeCount = GET_UShort();
+  count = GET_UShort();
+  cdf2->ClassRangeCount = 0; /* zero for now.  we fill with the number of good entries later */
 
   FORGET_Frame();
 
@@ -1063,15 +1050,22 @@ static FT_Error  Load_ClassDef2( HB_ClassDefinition*  cd,
     if ( crr[n].Start > crr[n].End ||
 	 crr[n].Class >= limit )
     {
-      error = HB_Err_Invalid_SubTable;
-      goto Fail;
+      /* XXX
+       * Corrupt entry.  Skip it.
+       * This is hit by Nafees Nastaliq font for example
+       */
+       n--;
+       count--;
     }
-    d[crr[n].Class] = TRUE;
+    else
+      d[crr[n].Class] = TRUE;
   }
 
   FORGET_Frame();
 
-  return FT_Err_Ok;
+  cdf2->ClassRangeCount = count;
+
+  return HB_Err_Ok;
 
 Fail:
   FREE( crr );
@@ -1089,11 +1083,11 @@ static void  Free_ClassDef2( HB_ClassDefFormat2*  cdf2,
 
 /* ClassDefinition */
 
-FT_Error  _HB_OPEN_Load_ClassDefinition( HB_ClassDefinition*  cd,
+HB_Error  _HB_OPEN_Load_ClassDefinition( HB_ClassDefinition*  cd,
 				FT_UShort             limit,
 				FT_Stream             stream )
 {
-  FT_Error   error;
+  HB_Error   error;
   FT_Memory  memory = stream->memory;
 
 
@@ -1109,17 +1103,9 @@ FT_Error  _HB_OPEN_Load_ClassDefinition( HB_ClassDefinition*  cd,
 
   switch ( cd->ClassFormat )
   {
-  case 1:
-    error = Load_ClassDef1( cd, limit, stream );
-    break;
-
-  case 2:
-    error = Load_ClassDef2( cd, limit, stream );
-    break;
-
-  default:
-    error = HB_Err_Invalid_SubTable_Format;
-    break;
+  case 1:  error = Load_ClassDef1( cd, limit, stream ); break;
+  case 2:  error = Load_ClassDef2( cd, limit, stream ); break;
+  default: error = _hb_err(HB_Err_Invalid_SubTable_Format);	break;
   }
 
   if ( error )
@@ -1127,7 +1113,7 @@ FT_Error  _HB_OPEN_Load_ClassDefinition( HB_ClassDefinition*  cd,
 
   cd->loaded = TRUE;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail:
   FREE( cd->Defined );
@@ -1135,10 +1121,10 @@ Fail:
 }
 
 
-FT_Error  _HB_OPEN_Load_EmptyClassDefinition( HB_ClassDefinition*  cd,
+HB_Error  _HB_OPEN_Load_EmptyClassDefinition( HB_ClassDefinition*  cd,
 				     FT_Stream             stream )
 {
-  FT_Error   error;
+  HB_Error   error;
   FT_Memory  memory = stream->memory;
 
 
@@ -1151,7 +1137,7 @@ FT_Error  _HB_OPEN_Load_EmptyClassDefinition( HB_ClassDefinition*  cd,
   if ( ALLOC_ARRAY( cd->cd.cd1.ClassValueArray, 1, FT_UShort ) )
     goto Fail;
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 
 Fail:
   FREE( cd->Defined );
@@ -1168,18 +1154,14 @@ void  _HB_OPEN_Free_ClassDefinition( HB_ClassDefinition*  cd,
 
   switch ( cd->ClassFormat )
   {
-  case 1:
-    Free_ClassDef1( &cd->cd.cd1, memory );
-    break;
-
-  case 2:
-    Free_ClassDef2( &cd->cd.cd2, memory );
-    break;
+  case 1:  Free_ClassDef1( &cd->cd.cd1, memory ); break;
+  case 2:  Free_ClassDef2( &cd->cd.cd2, memory ); break;
+  default:					  break;
   }
 }
 
 
-static FT_Error  Get_Class1( HB_ClassDefFormat1*  cdf1,
+static HB_Error  Get_Class1( HB_ClassDefFormat1*  cdf1,
 			     FT_UShort             glyphID,
 			     FT_UShort*            class,
 			     FT_UShort*            index )
@@ -1194,7 +1176,7 @@ static FT_Error  Get_Class1( HB_ClassDefFormat1*  cdf1,
        glyphID < cdf1->StartGlyph + cdf1->GlyphCount )
   {
     *class = cva[glyphID - cdf1->StartGlyph];
-    return FT_Err_Ok;
+    return HB_Err_Ok;
   }
   else
   {
@@ -1207,12 +1189,12 @@ static FT_Error  Get_Class1( HB_ClassDefFormat1*  cdf1,
 /* we need the index value of the last searched class range record
    in case of failure for constructed GDEF tables                  */
 
-static FT_Error  Get_Class2( HB_ClassDefFormat2*  cdf2,
+static HB_Error  Get_Class2( HB_ClassDefFormat2*  cdf2,
 			     FT_UShort             glyphID,
 			     FT_UShort*            class,
 			     FT_UShort*            index )
 {
-  FT_Error               error = FT_Err_Ok;
+  HB_Error               error = HB_Err_Ok;
   FT_UShort              min, max, new_min, new_max, middle;
 
   HB_ClassRangeRecord*  crr = cdf2->ClassRangeRecord;
@@ -1245,7 +1227,7 @@ static FT_Error  Get_Class2( HB_ClassDefFormat2*  cdf2,
     if ( glyphID >= crr[middle].Start && glyphID <= crr[middle].End )
     {
       *class = crr[middle].Class;
-      error  = FT_Err_Ok;
+      error  = HB_Err_Ok;
       break;
     }
     else if ( glyphID < crr[middle].Start )
@@ -1277,24 +1259,19 @@ static FT_Error  Get_Class2( HB_ClassDefFormat2*  cdf2,
 }
 
 
-FT_Error  _HB_OPEN_Get_Class( HB_ClassDefinition*  cd,
+HB_Error  _HB_OPEN_Get_Class( HB_ClassDefinition*  cd,
 		     FT_UShort             glyphID,
 		     FT_UShort*            class,
 		     FT_UShort*            index )
 {
   switch ( cd->ClassFormat )
   {
-  case 1:
-    return Get_Class1( &cd->cd.cd1, glyphID, class, index );
-
-  case 2:
-    return Get_Class2( &cd->cd.cd2, glyphID, class, index );
-
-  default:
-    return HB_Err_Invalid_SubTable_Format;
+  case 1:  return Get_Class1( &cd->cd.cd1, glyphID, class, index );
+  case 2:  return Get_Class2( &cd->cd.cd2, glyphID, class, index );
+  default: return _hb_err(HB_Err_Invalid_SubTable_Format);
   }
 
-  return FT_Err_Ok;               /* never reached */
+  return HB_Err_Ok;               /* never reached */
 }
 
 
@@ -1304,10 +1281,10 @@ FT_Error  _HB_OPEN_Get_Class( HB_ClassDefinition*  cd,
  ***************************/
 
 
-FT_Error  _HB_OPEN_Load_Device( HB_Device*  d,
+HB_Error  _HB_OPEN_Load_Device( HB_Device*  d,
 		       FT_Stream    stream )
 {
-  FT_Error   error;
+  HB_Error   error;
   FT_Memory  memory = stream->memory;
 
   FT_UShort   n, count;
@@ -1324,11 +1301,18 @@ FT_Error  _HB_OPEN_Load_Device( HB_Device*  d,
 
   FORGET_Frame();
 
+  d->DeltaValue = NULL;
+
   if ( d->StartSize > d->EndSize ||
        d->DeltaFormat == 0 || d->DeltaFormat > 3 )
-    return HB_Err_Invalid_SubTable;
-
-  d->DeltaValue = NULL;
+    {
+      /* XXX
+       * I've seen fontforge generate DeltaFormat == 0.
+       * Just return Ok and let the NULL DeltaValue disable
+       * this table.
+       */
+      return HB_Err_Ok;
+    }
 
   count = ( ( d->EndSize - d->StartSize + 1 ) >>
 	      ( 4 - d->DeltaFormat ) ) + 1;
@@ -1349,7 +1333,7 @@ FT_Error  _HB_OPEN_Load_Device( HB_Device*  d,
 
   FORGET_Frame();
 
-  return FT_Err_Ok;
+  return HB_Err_Ok;
 }
 
 
@@ -1395,7 +1379,7 @@ void  _HB_OPEN_Free_Device( HB_Device*  d,
 
      mask = 0x00FF                                    */
 
-FT_Error  _HB_OPEN_Get_Device( HB_Device*  d,
+HB_Error  _HB_OPEN_Get_Device( HB_Device*  d,
 		      FT_UShort    size,
 		      FT_Short*    value )
 {
@@ -1418,7 +1402,7 @@ FT_Error  _HB_OPEN_Get_Device( HB_Device*  d,
     if ( *value >= ( ( mask + 1 ) >> 1 ) )
       *value -= mask + 1;
 
-    return FT_Err_Ok;
+    return HB_Err_Ok;
   }
   else
   {
diff --git a/pango/opentype/harfbuzz-open.h b/pango/opentype/harfbuzz-open.h
index 17e1f29b..5864405c 100644
--- a/pango/opentype/harfbuzz-open.h
+++ b/pango/opentype/harfbuzz-open.h
@@ -25,12 +25,21 @@ FT_BEGIN_HEADER
 
 #define HB_MAX_NESTING_LEVEL             100
 
+typedef FT_Error HB_Error;
+
+#define HB_Err_Invalid_Argument          FT_Err_Invalid_Argument
+#define HB_Err_Invalid_Face_Handle       FT_Err_Invalid_Face_Handle
+#define HB_Err_Invalid_Stream_Operation  FT_Err_Invalid_Stream_Operation
+#define HB_Err_Empty_Script              0x1005
+
+#define HB_Err_Ok                        FT_Err_Ok
+#define HB_Err_Not_Covered               0x1002
+#define HB_Err_Out_Of_Memory             FT_Err_Out_Of_Memory
+#define HB_Err_Table_Missing             FT_Err_Table_Missing
 #define HB_Err_Invalid_SubTable_Format   0x1000
 #define HB_Err_Invalid_SubTable          0x1001
-#define HB_Err_Not_Covered               0x1002
 #define HB_Err_Too_Many_Nested_Contexts  0x1003
 #define HB_Err_No_MM_Interpreter         0x1004
-#define HB_Err_Empty_Script              0x1005
 
 
 /* Script list related structures */
diff --git a/pango/pango-ot-buffer.c b/pango/pango-ot-buffer.c
index f84c4cd3..39a63060 100644
--- a/pango/pango-ot-buffer.c
+++ b/pango/pango-ot-buffer.c
@@ -47,7 +47,7 @@ pango_ot_buffer_new (PangoFcFont *font)
   PangoOTBuffer *buffer = g_slice_new (PangoOTBuffer);
   FT_Face face = pango_fc_font_lock_face (font);
 
-  if (hb_buffer_new (face->memory, &buffer->buffer) != FT_Err_Ok)
+  if (hb_buffer_new (face->memory, &buffer->buffer) != HB_Err_Ok)
     g_warning ("Allocation of HB_Buffer failed"); /* this doesn't happen */
 
   buffer->font = g_object_ref (font);
@@ -339,7 +339,7 @@ pango_ot_buffer_output (const PangoOTBuffer *buffer,
 
 	  if (buffer->zero_width_marks &&
 	      gdef &&
-	      HB_GDEF_Get_Glyph_Property (gdef, glyphs->glyphs[i].glyph, &property) == FT_Err_Ok &&
+	      HB_GDEF_Get_Glyph_Property (gdef, glyphs->glyphs[i].glyph, &property) == HB_Err_Ok &&
 	      (property == HB_GDEF_MARK || (property & HB_LOOKUP_FLAG_IGNORE_SPECIAL_MARKS) != 0))
 	    {
 	      glyphs->glyphs[i].geometry.width = 0;
diff --git a/pango/pango-ot-info.c b/pango/pango-ot-info.c
index ba5633ff..a9db1916 100644
--- a/pango/pango-ot-info.c
+++ b/pango/pango-ot-info.c
@@ -202,8 +202,8 @@ set_unicode_charmap (FT_Face face)
   for (charmap = 0; charmap < face->num_charmaps; charmap++)
     if (face->charmaps[charmap]->encoding == ft_encoding_unicode)
       {
-	FT_Error error = FT_Set_Charmap(face, face->charmaps[charmap]);
-	return error == FT_Err_Ok;
+	HB_Error error = FT_Set_Charmap(face, face->charmaps[charmap]);
+	return error == HB_Err_Ok;
       }
 
   return FALSE;
@@ -289,7 +289,7 @@ pango_ot_info_get_gdef (PangoOTInfo *info)
 
   if (!(info->loaded & INFO_LOADED_GDEF))
     {
-      FT_Error error;
+      HB_Error error;
 
       info->loaded |= INFO_LOADED_GDEF;
 
@@ -297,7 +297,7 @@ pango_ot_info_get_gdef (PangoOTInfo *info)
 	{
 	  error = HB_Load_GDEF_Table (info->face, &info->gdef);
 
-	  if (error && error != FT_Err_Table_Missing)
+	  if (error && error != HB_Err_Table_Missing)
 	    g_warning ("Error loading GDEF table %d", error);
 
 	  if (!info->gdef)
@@ -318,7 +318,7 @@ pango_ot_info_get_gsub (PangoOTInfo *info)
 
   if (!(info->loaded & INFO_LOADED_GSUB))
     {
-      FT_Error error;
+      HB_Error error;
       HB_GDEF gdef = pango_ot_info_get_gdef (info);
 
       info->loaded |= INFO_LOADED_GSUB;
@@ -327,7 +327,7 @@ pango_ot_info_get_gsub (PangoOTInfo *info)
 	{
 	  error = HB_Load_GSUB_Table (info->face, &info->gsub, gdef);
 
-	  if (error && error != FT_Err_Table_Missing)
+	  if (error && error != HB_Err_Table_Missing)
 	    g_warning ("Error loading GSUB table %d", error);
 	}
     }
@@ -342,7 +342,7 @@ pango_ot_info_get_gpos (PangoOTInfo *info)
 
   if (!(info->loaded & INFO_LOADED_GPOS))
     {
-      FT_Error error;
+      HB_Error error;
       HB_GDEF gdef = pango_ot_info_get_gdef (info);
 
       info->loaded |= INFO_LOADED_GPOS;
@@ -351,7 +351,7 @@ pango_ot_info_get_gpos (PangoOTInfo *info)
 	{
 	  error = HB_Load_GPOS_Table (info->face, &info->gpos, gdef);
 
-	  if (error && error != FT_Err_Table_Missing)
+	  if (error && error != HB_Err_Table_Missing)
 	    g_warning ("Error loading GPOS table %d", error);
 	}
     }
diff --git a/pango/pango-ot-ruleset.c b/pango/pango-ot-ruleset.c
index a40019fa..f484c4e0 100644
--- a/pango/pango-ot-ruleset.c
+++ b/pango/pango-ot-ruleset.c
@@ -564,7 +564,7 @@ pango_ot_ruleset_position (const PangoOTRuleset *ruleset,
 
   if (HB_GPOS_Apply_String (ruleset->info->face, gpos, 0, buffer->buffer,
 			    FALSE /* enable device-dependant values */,
-			    buffer->rtl) == FT_Err_Ok)
+			    buffer->rtl) == HB_Err_Ok)
     buffer->applied_gpos = TRUE;
 }