[gs-cvs] rev 8896 - trunk/gs/src

[giles at ghostscript.com]

Author: giles
Date: 2008-07-28 21:44:05 -0700 (Mon, 28 Jul 2008)
New Revision: 8896

Modified:
   trunk/gs/src/scfd.c
Log:
Avoid a segfault with invalid ccitt fax data streams. Bug 689917.
Patch from Tim Waugh.

EXPECTED DIFFERENCES:

None.


Modified: trunk/gs/src/scfd.c
===================================================================
--- trunk/gs/src/scfd.c	2008-07-28 22:23:04 UTC (rev 8895)
+++ trunk/gs/src/scfd.c	2008-07-29 04:44:05 UTC (rev 8896)
@@ -161,7 +161,7 @@
 /* makeup codes efficiently, since these are always a multiple of 64. */
 #define invert_data(rlen, black_byte, makeup_action, d)\
 	if ( rlen > qbit )\
-	{	*q++ ^= (1 << qbit) - 1;\
+	{	if (q >= ss->lbuf) *q++ ^= (1 << qbit) - 1; else q++;\
 		rlen -= qbit;\
 		switch ( rlen >> 3 )\
 		{\