* src/truetype/ttgload.c (compute_glyph_metrics): Fix overflow.

Reported as https://bugs.chromium.org/p/chromium/issues/detail?id=777151
7 years ago · 720ae67f35
parent ced9c311f6
commit 720ae67f35
2 changed files with 11 additions and 3 deletions
--- a/8
+++ b/8
@ -1,3 +1,11 @@
+2018-08-05  Werner Lemberg  <wl@gnu.org>
+
+	* src/truetype/ttgload.c (compute_glyph_metrics): Fix overflow.
+
+	Reported as
+
+	  https://bugs.chromium.org/p/chromium/issues/detail?id=777151
+
 2018-08-04  Werner Lemberg  <wl@gnu.org>

 	* src/truetype/ttinterp.c (opcode_name): Fix typos.
--- a/src/truetype/ttgload.c
+++ b/src/truetype/ttgload.c
@ -2284,13 +2284,13 @@
      /* XXX: for now, we have no better algorithm for the lsb, but it */
      /*      should work fine.                                        */
      /*                                                               */
-      glyph->metrics.vertBearingX = glyph->metrics.horiBearingX -
-                                      glyph->metrics.horiAdvance / 2;
+      glyph->metrics.vertBearingX = SUB_LONG( glyph->metrics.horiBearingX,
+                                              glyph->metrics.horiAdvance / 2 );
      glyph->metrics.vertBearingY = top;
      glyph->metrics.vertAdvance  = advance;
    }

-    return 0;
+    return FT_Err_Ok;
  }