[Pixman] [PATCH] When pixman_compute_composite_region32() return FALSE, don't fini the region.

[Søren Sandmann]

From: Søren Sandmann Pedersen <ssp at redhat.com>

The rule is that the region passed in must be initialized and that the
region returned will still be valid. Ie., the lifecycle is the
responsibility of the caller, regardless of what the function returns.

Previously, composite_region32() would finalize the region and then
return FALSE, and then the caller would finalize the region again,
leading to memory corruption in some cases.
---
 pixman/pixman.c |   14 +-------------
 1 files changed, 1 insertions(+), 13 deletions(-)

diff --git a/pixman/pixman.c b/pixman/pixman.c
index 402c72c..62b58b8 100644
--- a/pixman/pixman.c
+++ b/pixman/pixman.c
@@ -302,17 +302,13 @@ pixman_compute_composite_region32 (pixman_region32_t * region,
     if (region->extents.x1 >= region->extents.x2 ||
         region->extents.y1 >= region->extents.y2)
     {
-	pixman_region32_init (region);
 	return FALSE;
     }
 
     if (dst_image->common.have_clip_region)
     {
 	if (!clip_general_image (region, &dst_image->common.clip_region, 0, 0))
-	{
-	    pixman_region32_fini (region);
 	    return FALSE;
-	}
     }
 
     if (dst_image->common.alpha_map && dst_image->common.alpha_map->common.have_clip_region)
@@ -321,7 +317,6 @@ pixman_compute_composite_region32 (pixman_region32_t * region,
 	                         -dst_image->common.alpha_origin_x,
 	                         -dst_image->common.alpha_origin_y))
 	{
-	    pixman_region32_fini (region);
 	    return FALSE;
 	}
     }
@@ -330,10 +325,7 @@ pixman_compute_composite_region32 (pixman_region32_t * region,
     if (src_image->common.have_clip_region)
     {
 	if (!clip_source_image (region, src_image, dest_x - src_x, dest_y - src_y))
-	{
-	    pixman_region32_fini (region);
 	    return FALSE;
-	}
     }
     if (src_image->common.alpha_map && src_image->common.alpha_map->common.have_clip_region)
     {
@@ -341,7 +333,6 @@ pixman_compute_composite_region32 (pixman_region32_t * region,
 	                        dest_x - (src_x - src_image->common.alpha_origin_x),
 	                        dest_y - (src_y - src_image->common.alpha_origin_y)))
 	{
-	    pixman_region32_fini (region);
 	    return FALSE;
 	}
     }
@@ -349,17 +340,14 @@ pixman_compute_composite_region32 (pixman_region32_t * region,
     if (mask_image && mask_image->common.have_clip_region)
     {
 	if (!clip_source_image (region, mask_image, dest_x - mask_x, dest_y - mask_y))
-	{
-	    pixman_region32_fini (region);
 	    return FALSE;
-	}
+
 	if (mask_image->common.alpha_map && mask_image->common.alpha_map->common.have_clip_region)
 	{
 	    if (!clip_source_image (region, (pixman_image_t *)mask_image->common.alpha_map,
 	                            dest_x - (mask_x - mask_image->common.alpha_origin_x),
 	                            dest_y - (mask_y - mask_image->common.alpha_origin_y)))
 	    {
-		pixman_region32_fini (region);
 		return FALSE;
 	    }
 	}
-- 
1.6.0.6