[sfnt] Make `tt_cmap4_char_map_linear' more robust (#46078).

* src/sfnt/ttcmap.c (tt_cmap4_char_map_linear): Take care of
border conditions (i.e., if the loop exits naturally).

ChangeLog

@@ -1,3 +1,10 @@
+2015-10-01  Werner Lemberg  <wl@gnu.org>
+
+	[sfnt] Make `tt_cmap4_char_map_linear' more robust (#46078).
+
+	* src/sfnt/ttcmap.c (tt_cmap4_char_map_linear): Take care of
+	border conditions (i.e., if the loop exits naturally).
+
 2015-10-01  Werner Lemberg  <wl@gnu.org>
 
 	* src/autofit/afranges.c (af_deva_nonbase_uniranges): Fix ranges.

src/sfnt/ttcmap.c

@@ -1130,18 +1130,16 @@
             /* we have an invalid glyph index; if there is an overflow, */
             /* we can adjust `charcode', otherwise the whole segment is */
             /* invalid                                                  */
+            gindex = 0;
+
             if ( (FT_Int)charcode + delta < 0 &&
                  (FT_Int)end + delta >= 0     )
-            {
               charcode = (FT_UInt)( -delta );
-              gindex   = 0;
-            }
+
             else if ( (FT_Int)charcode + delta < 0x10000L &&
                       (FT_Int)end + delta >= 0x10000L     )
-            {
               charcode = (FT_UInt)( 0x10000L - delta );
-              gindex   = 0;
-            }
+
             else
               continue;
           }