[PATCH xserver 1/2 v2] glamor: handle NULL source picture

[Olivier Fourdan]

COMPOSITE_REGION() can pass NULL as a source picture, make sure we
handle that nicely in both glamor_composite_clipped_region() and
glamor_composite_choose_shader().

Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=101894
Signed-off-by: Olivier Fourdan <ofourdan at redhat.com>
---
 v2: Make sure we can deal with a NULL source picture in both
     glamor_composite_clipped_region() and glamor_composite_choose_shader()

 glamor/glamor_render.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/glamor/glamor_render.c b/glamor/glamor_render.c
index 52f073d05..a8b208101 100644
--- a/glamor/glamor_render.c
+++ b/glamor/glamor_render.c
@@ -992,7 +992,7 @@ glamor_composite_choose_shader(CARD8 op,
                 goto fail;
             }
         } else {
-            if (!glamor_render_format_is_supported(source->format)) {
+            if (source && !glamor_render_format_is_supported(source->format)) {
                 glamor_fallback("Unsupported source picture format.\n");
                 goto fail;
             }
@@ -1411,7 +1411,8 @@ glamor_composite_clipped_region(CARD8 op,
            x_source, y_source, x_mask, y_mask, x_dest, y_dest, width, height);
 
     /* Is the composite operation equivalent to a copy? */
-    if (!mask && !source->alphaMap && !dest->alphaMap
+    if (source &&
+        !mask && !source->alphaMap && !dest->alphaMap
         && source->pDrawable && !source->transform
         /* CopyArea is only defined with matching depths. */
         && dest->pDrawable->depth == source->pDrawable->depth
-- 
2.13.3