cairo-region-clip.patch

# HG changeset patch
# User Matt Woodrow <mwoodrow@mozilla.com>
# Date 1408674084 -43200
#      Fri Aug 22 14:21:24 2014 +1200
# Node ID 2b819b882c3b26c02d821e8d713591a9b56f1728
# Parent  ffd1fc7e7d5a85e4823b5f2067b4a24d358a0e41
Bug 1050788 - Fix cairo clip path region construction when the first path generates no traps. r=jrmuizel

diff --git a/gfx/cairo/cairo/src/cairo-clip.c b/gfx/cairo/cairo/src/cairo-clip.c
--- a/gfx/cairo/cairo/src/cairo-clip.c
+++ b/gfx/cairo/cairo/src/cairo-clip.c
@@ -590,16 +590,22 @@ static cairo_int_status_t
     status = _cairo_path_fixed_fill_rectilinear_to_traps (&clip_path->path,
 							  clip_path->fill_rule,
 							  &traps);
     if (unlikely (_cairo_status_is_error (status)))
 	return status;
     if (status == CAIRO_INT_STATUS_UNSUPPORTED)
 	goto UNSUPPORTED;
 
+    if (unlikely (traps.num_traps == 0)) {
+	clip_path->region = cairo_region_create ();
+	clip_path->flags |= CAIRO_CLIP_PATH_HAS_REGION;
+	return CAIRO_STATUS_SUCCESS;
+    }
+
     if (traps.num_traps > ARRAY_LENGTH (stack_boxes)) {
 	boxes = _cairo_malloc_ab (traps.num_traps, sizeof (cairo_box_t));
 	if (unlikely (boxes == NULL))
 	    return _cairo_error (CAIRO_STATUS_NO_MEMORY);
     }
 
     for (n = 0; n < traps.num_traps; n++) {
 	boxes[n].p1.x = traps.traps[n].left.p1.x;