truetype: Truncate the deltas of composite glyph at 16-bit values.
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diff --git a/ChangeLog b/ChangeLog
index 3de1bba..b91d029 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,18 @@
2009-07-31 suzuki toshiya <mpsuzuki@hiroshima-u.ac.jp>
+ truetype: Truncate the deltas of composite glyph at 16-bit values.
+
+ * src/truetype/ttgload.c (load_truetype_glyph):
+ Insert cast from FT_Long (deltas[i].{x,y}) to
+ FT_Int16 in the summation of deltas[] for composite
+ glyphs. Because deltas[i] is typed as FT_Pos,
+ its component x, y are typed as FT_Long, but
+ their sources are always FT_Int16 when they are
+ loaded by ft_var_readpackeddeltas(). However,
+ the limitation about the summed deltas is unclear.
+
+2009-07-31 suzuki toshiya <mpsuzuki@hiroshima-u.ac.jp>
+
truetype: Truncate the instructions upto 16-bit per a glyph.
* src/truetype/ttgload.c (TT_Hint_Glyph): Truncate
diff --git a/src/truetype/ttgload.c b/src/truetype/ttgload.c
index 5d48e8f..b0f6810 100644
--- a/src/truetype/ttgload.c
+++ b/src/truetype/ttgload.c
@@ -1400,8 +1400,11 @@
{
if ( subglyph->flags & ARGS_ARE_XY_VALUES )
{
- subglyph->arg1 += deltas[i].x;
- subglyph->arg2 += deltas[i].y;
+ /* XXX: overflow check for subglyph->{arg1,arg2}. */
+ /* deltas[i].{x,y} must be within signed 16-bit, */
+ /* but the restriction of summed delta is not clear */
+ subglyph->arg1 += (FT_Int16)deltas[i].x;
+ subglyph->arg2 += (FT_Int16)deltas[i].y;
}
}