Revisions to FAPI (error handling etc).

A lot of the FAPI methods made no account for errors (i.e. a call to return an
unsigned 16 bit value would return an unsigned short int). In various places
that meant we ended up using unlikely (in practice, impossible, yet still
"valid") values to indicate an error condition.

This commit changes those calls to have a conventional Ghostscript "int"
return value and (mostly) take pointer to the storage into which they should
write their value. We can now return meaninful error codes.

Secondly, in several places, the FAPI methods and code used integers to store
character codes, cids, gids etc. This is less than ideal because we potentially
have to handle 4 byte codes (especially for gids), and we also use some
special 64 bit values (when available) for specific meanings. There were
several workarounds for that, in various places.

This commit also changes the FAPI API and code to the gs_glyph type for all
such values, removing the need for those workarounds

1 files changed, 24 insertions, 16 deletions

diff --git a/base/fapi_ft.c b/base/fapi_ft.c
index a79e352ac..46f865efa 100644
--- a/base/fapi_ft.c
+++ b/base/fapi_ft.c
@@ -1114,7 +1114,7 @@ gs_fapi_ft_get_scaled_font(gs_fapi_server * a_server, gs_fapi_font * a_font,
     ff_server *s = (ff_server *) a_server;
     ff_face *face = (ff_face *) a_font->server_font_data;
     FT_Error ft_error = 0;
-    int i, j;
+    int i, j, code;
     FT_CharMap cmap = NULL;
     bool data_owned = true;
 
@@ -1183,7 +1183,6 @@ gs_fapi_ft_get_scaled_font(gs_fapi_server * a_server, gs_fapi_font * a_font,
         /* Load a typeface from a file. */
         else if (a_font->font_file_path) {
             FT_Open_Args args;
-            int code;
 
             memset(&args, 0x00, sizeof(args));
 
@@ -1215,9 +1214,12 @@ gs_fapi_ft_get_scaled_font(gs_fapi_server * a_server, gs_fapi_font * a_font,
 
             if (a_font->is_type1) {
                 long length;
-                int type =
-                    a_font->get_word(a_font, gs_fapi_font_feature_FontType,
-                                     0);
+                unsigned short type = 0;
+
+                code = a_font->get_word(a_font, gs_fapi_font_feature_FontType, 0, &type);
+                if (code < 0) {
+                    return code;
+                }
 
                 /* Tell the FAPI interface that we need to decrypt the /Subrs data. */
                 a_font->need_decrypt = true;
@@ -1230,6 +1232,7 @@ gs_fapi_ft_get_scaled_font(gs_fapi_server * a_server, gs_fapi_font * a_font,
                     length = gs_fapi_serialize_type1_font(a_font, NULL, 0);
                 else
                     length = gs_fapi_serialize_type2_font(a_font, NULL, 0);
+
                 open_args.memory_base = own_font_data =
                     FF_alloc(s->ftmemory, length);
                 if (!open_args.memory_base)
@@ -1237,14 +1240,14 @@ gs_fapi_ft_get_scaled_font(gs_fapi_server * a_server, gs_fapi_font * a_font,
                 own_font_data_len = length;
                 if (type == 1)
                     open_args.memory_size =
-                        gs_fapi_serialize_type1_font(a_font, own_font_data,
-                                                     length);
+                        gs_fapi_serialize_type1_font(a_font, own_font_data, length);
                 else
                     open_args.memory_size =
-                        gs_fapi_serialize_type2_font(a_font, own_font_data,
-                                                     length);
+                        gs_fapi_serialize_type2_font(a_font, own_font_data, length);
+
                 if (open_args.memory_size != length)
                     return_error(gs_error_unregistered);        /* Must not happen. */
+
                 ft_inc_int = new_inc_int(a_server, a_font);
                 if (!ft_inc_int) {
                     FF_free(s->ftmemory, own_font_data);
@@ -1255,11 +1258,16 @@ gs_fapi_ft_get_scaled_font(gs_fapi_server * a_server, gs_fapi_font * a_font,
             /* It must be type 42 (see code in FAPI_FF_get_glyph in zfapi.c). */
             else {
                 /* Get the length of the TrueType data. */
-                open_args.memory_size =
-                    a_font->get_long(a_font, gs_fapi_font_feature_TT_size, 0);
-                if (open_args.memory_size == 0)
+                unsigned long ms;
+
+                code = a_font->get_long(a_font, gs_fapi_font_feature_TT_size, 0, &ms);
+                if (code < 0)
+                    return code;
+                if (ms == 0)
                     return_error(gs_error_invalidfont);
 
+                open_args.memory_size = (FT_Long)ms;
+
                 /* Load the TrueType data into a single buffer. */
                 open_args.memory_base = own_font_data =
                     FF_alloc(s->ftmemory, open_args.memory_size);
@@ -1268,10 +1276,10 @@ gs_fapi_ft_get_scaled_font(gs_fapi_server * a_server, gs_fapi_font * a_font,
 
                 own_font_data_len = open_args.memory_size;
 
-                if (a_font->
-                    serialize_tt_font(a_font, own_font_data,
-                                      open_args.memory_size))
-                    return_error(gs_error_invalidfont);
+                code = a_font->serialize_tt_font(a_font, own_font_data,
+                                      open_args.memory_size);
+                if (code < 0)
+                    return code;
 
                 /* We always load incrementally. */
                 ft_inc_int = new_inc_int(a_server, a_font);