[cairo] pixman crash from setting clip region on image surface (patch)

[Vladimir Vukicevic]

Hi,

If an cairo_init_clip is called on an image surface, 
_cairo_image_surface_set_clip_region ends up with a NULL region, which 
it then passes to pixman_image_set_clip_region. 
pixman_image_set_clip_region assumes that the region is valid, and sets 
up the clip type accordingly; this causes a crash later on when the 
region is reset, because it tries to free NULL.

The attached patch fixes this; just a patch to icimage.c to check if the 
region is not NULL before setting a new clipping region.

	- Vlad

-------------- next part --------------
Index: src/icimage.c
===================================================================
RCS file: /cvs/cairo/libpixman/src/icimage.c,v
retrieving revision 1.19
diff -u -u -r1.19 icimage.c
--- src/icimage.c	16 Apr 2004 15:32:53 -0000	1.19
+++ src/icimage.c	6 May 2004 03:19:10 -0000
@@ -263,8 +263,10 @@
 		      pixman_region16_t	*region)
 {
     pixman_image_destroyClip (image);
-    image->clientClip = region;
-    image->clientClipType = CT_REGION;
+    if (region != NULL) {
+        image->clientClip = region;
+        image->clientClipType = CT_REGION;
+    }
     image->stateChanges |= CPClipMask;
     return 0;
 }