From 00de16b7ac54d4c620e0be3565c83f58e01567ac Mon Sep 17 00:00:00 2001

From: Benjamin Otte <otte@redhat.com>

Date: Sat, 4 Jun 2011 13:47:15 +0200

Subject: [PATCH] image: Don't crash on weird pixman formats

_pixel_to_solid() used to assert that it got a known cairo_format_t.

However, this might not be the case when backends decide to use a pixman

format that is not representable by a cairo format (X and DirectFB are

examples for backends that do that).

This patch makes _pixel_to_solid() return NULL in that case and fixes

the callers to deal with it.

https://bugs.freedesktop.org/show_bug.cgi?id=37916

---

 src/cairo-image-surface.c |   23 ++++++++++++++++-------

 1 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/src/cairo-image-surface.c b/src/cairo-image-surface.c

index 93ccfe5..a2345b2 100644

--- a/src/cairo-image-surface.c

+++ b/src/cairo-image-surface.c

@@ -1246,10 +1246,12 @@ _pixel_to_solid (cairo_image_surface_t *image, int x, int y)

     switch (image->format) {

     default:

-    case CAIRO_FORMAT_INVALID:

 	ASSERT_NOT_REACHED;

 	return NULL;

+    case CAIRO_FORMAT_INVALID:

+	return NULL;

+

     case CAIRO_FORMAT_A1:

 	pixel = *(uint8_t *) (image->data + y * image->stride + x/8);

 	return pixel & (1 << (x&7)) ? _pixman_black_image () : _pixman_transparent_image ();

@@ -1364,7 +1366,9 @@ _pixman_image_for_surface (const cairo_surface_pattern_t *pattern,

 		}

 		else

 		{

-		    return _pixel_to_solid (source, sample.x, sample.y);

+		    pixman_image = _pixel_to_solid (source, sample.x, sample.y);

+                    if (pixman_image)

+                        return pixman_image;

 		}

 	    }

@@ -1403,9 +1407,11 @@ _pixman_image_for_surface (const cairo_surface_pattern_t *pattern,

 	    if (sample.width == 1 && sample.height == 1) {

 		if (is_contained) {

-		    return _pixel_to_solid (source,

-					    sub->extents.x + sample.x,

-					    sub->extents.y + sample.y);

+		    pixman_image = _pixel_to_solid (source,

+                                                    sub->extents.x + sample.x,

+                                                    sub->extents.y + sample.y);

+                    if (pixman_image)

+                        return pixman_image;

 		} else {

 		    if (extend == CAIRO_EXTEND_NONE)

 			return _pixman_transparent_image ();

@@ -1468,8 +1474,11 @@ _pixman_image_for_surface (const cairo_surface_pattern_t *pattern,

 	    else

 	    {

 		pixman_image = _pixel_to_solid (image, sample.x, sample.y);

-		_cairo_surface_release_source_image (pattern->surface, image, extra);

-		return pixman_image;

+                if (pixman_image)

+                {

+                    _cairo_surface_release_source_image (pattern->surface, image, extra);

+                    return pixman_image;

+                }

 	    }

 	}

-- 

1.7.7.6