[autofit, pshinter] Use `FT_OFFSET`.

This avoids

```
runtime error: applying zero offset to null pointer
```

warnings of clang's undefined behaviour sanitizer.

* src/autofit/afcjk.c (af_cjk_hints_link_segments,
af_cjk_hints_compute_edges, af_cjk_hints_compute_blue_edges,
af_cjk_hint_edges, af_cjk_align_edge_points): Do it.

* src/autofit/afhints.c (af_glyph_hints_align_edge_points,
af_glyph_hints_align_strong_points): Ditto.

* src/autofit/aflatin.c (af_latin_metrics_init_widths,
af_latin_hints_link_segments, af_latin_hints_compute_edges,
af_latin_hints_compute_blue_edges, af_latin_hint_edges): Ditto.

* src/pshinter/pshalgo.c (psh_hint_table_init): Ditto.

4 files changed, 14 insertions, 14 deletions

diff --git a/src/autofit/afcjk.c b/src/autofit/afcjk.c
index 7e46b6b1e..03a8a6f83 100644
--- a/src/autofit/afcjk.c
+++ b/src/autofit/afcjk.c
@@ -843,7 +843,7 @@
   {
     AF_AxisHints  axis          = &hints->axis[dim];
     AF_Segment    segments      = axis->segments;
-    AF_Segment    segment_limit = segments + axis->num_segments;
+    AF_Segment    segment_limit = FT_OFFSET( segments, axis->num_segments );
     AF_Direction  major_dir     = axis->major_dir;
     AF_Segment    seg1, seg2;
     FT_Pos        len_threshold;
@@ -1005,7 +1005,7 @@
     AF_CJKAxis    laxis  = &((AF_CJKMetrics)hints->metrics)->axis[dim];
 
     AF_Segment    segments      = axis->segments;
-    AF_Segment    segment_limit = segments + axis->num_segments;
+    AF_Segment    segment_limit = FT_OFFSET( segments, axis->num_segments );
     AF_Segment    seg;
 
     FT_Fixed      scale;
@@ -1153,7 +1153,7 @@
      */
     {
       AF_Edge  edges      = axis->edges;
-      AF_Edge  edge_limit = edges + axis->num_edges;
+      AF_Edge  edge_limit = FT_OFFSET( edges, axis->num_edges );
       AF_Edge  edge;
 
 
@@ -1291,7 +1291,7 @@
   {
     AF_AxisHints  axis       = &hints->axis[dim];
     AF_Edge       edge       = axis->edges;
-    AF_Edge       edge_limit = edge + axis->num_edges;
+    AF_Edge       edge_limit = FT_OFFSET( edge, axis->num_edges );
     AF_CJKAxis    cjk        = &metrics->axis[dim];
     FT_Fixed      scale      = cjk->scale;
     FT_Pos        best_dist0;  /* initial threshold */
@@ -1798,7 +1798,7 @@
   {
     AF_AxisHints  axis       = &hints->axis[dim];
     AF_Edge       edges      = axis->edges;
-    AF_Edge       edge_limit = edges + axis->num_edges;
+    AF_Edge       edge_limit = FT_OFFSET( edges, axis->num_edges );
     FT_PtrDist    n_edges;
     AF_Edge       edge;
     AF_Edge       anchor   = NULL;
@@ -2177,7 +2177,7 @@
   {
     AF_AxisHints  axis       = & hints->axis[dim];
     AF_Edge       edges      = axis->edges;
-    AF_Edge       edge_limit = edges + axis->num_edges;
+    AF_Edge       edge_limit = FT_OFFSET( edges, axis->num_edges );
     AF_Edge       edge;
     FT_Bool       snapping;
 
diff --git a/src/autofit/afhints.c b/src/autofit/afhints.c
index 5506afda2..f17303614 100644
--- a/src/autofit/afhints.c
+++ b/src/autofit/afhints.c
@@ -1316,7 +1316,7 @@
   {
     AF_AxisHints  axis          = & hints->axis[dim];
     AF_Segment    segments      = axis->segments;
-    AF_Segment    segment_limit = segments + axis->num_segments;
+    AF_Segment    segment_limit = FT_OFFSET( segments, axis->num_segments );
     AF_Segment    seg;
 
 
@@ -1393,7 +1393,7 @@
     AF_Point      point_limit = points + hints->num_points;
     AF_AxisHints  axis        = &hints->axis[dim];
     AF_Edge       edges       = axis->edges;
-    AF_Edge       edge_limit  = edges + axis->num_edges;
+    AF_Edge       edge_limit  = FT_OFFSET( edges, axis->num_edges );
     FT_UInt       touch_flag;
 
 
diff --git a/src/autofit/aflatin.c b/src/autofit/aflatin.c
index 5e81d771a..896aed5da 100644
--- a/src/autofit/aflatin.c
+++ b/src/autofit/aflatin.c
@@ -200,7 +200,7 @@
                                       (AF_Dimension)dim );
 
         seg   = axhints->segments;
-        limit = seg + axhints->num_segments;
+        limit = FT_OFFSET( seg, axhints->num_segments );
 
         for ( ; seg < limit; seg++ )
         {
@@ -1989,7 +1989,7 @@
   {
     AF_AxisHints  axis          = &hints->axis[dim];
     AF_Segment    segments      = axis->segments;
-    AF_Segment    segment_limit = segments + axis->num_segments;
+    AF_Segment    segment_limit = FT_OFFSET( segments, axis->num_segments );
     FT_Pos        len_threshold, len_score, dist_score, max_width;
     AF_Segment    seg1, seg2;
 
@@ -2134,7 +2134,7 @@
     FT_Bool  top_to_bottom_hinting = 0;
 
     AF_Segment    segments      = axis->segments;
-    AF_Segment    segment_limit = segments + axis->num_segments;
+    AF_Segment    segment_limit = FT_OFFSET( segments, axis->num_segments );
     AF_Segment    seg;
 
 #if 0
@@ -2500,7 +2500,7 @@
   {
     AF_AxisHints  axis       = &hints->axis[AF_DIMENSION_VERT];
     AF_Edge       edge       = axis->edges;
-    AF_Edge       edge_limit = edge + axis->num_edges;
+    AF_Edge       edge_limit = FT_OFFSET( edge, axis->num_edges );
     AF_LatinAxis  latin      = &metrics->axis[AF_DIMENSION_VERT];
     FT_Fixed      scale      = latin->scale;
 
@@ -2993,7 +2993,7 @@
   {
     AF_AxisHints  axis       = &hints->axis[dim];
     AF_Edge       edges      = axis->edges;
-    AF_Edge       edge_limit = edges + axis->num_edges;
+    AF_Edge       edge_limit = FT_OFFSET( edges, axis->num_edges );
     FT_PtrDist    n_edges;
     AF_Edge       edge;
     AF_Edge       anchor     = NULL;
diff --git a/src/pshinter/pshalgo.c b/src/pshinter/pshalgo.c
index 227caeae3..bea907f30 100644
--- a/src/pshinter/pshalgo.c
+++ b/src/pshinter/pshalgo.c
@@ -188,7 +188,7 @@
       goto Exit;
 
     table->max_hints   = count;
-    table->sort_global = table->sort + count;
+    table->sort_global = FT_OFFSET( table->sort, count );
     table->num_hints   = 0;
     table->num_zones   = 0;
     table->zone        = NULL;