script: Simply exchange source/dest images for _set_source_image

But note we can only do the exchange if they do indeed match and
there are no other references (the objects are only on the stack).

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 14 insertions, 5 deletions

diff --git a/util/cairo-script/cairo-script-operators.c b/util/cairo-script/cairo-script-operators.c
index efc1970cf..71d2b79b7 100644
--- a/util/cairo-script/cairo-script-operators.c
+++ b/util/cairo-script/cairo-script-operators.c
@@ -5356,11 +5356,20 @@ _set_source_image (csi_t *ctx)
      * principally to remove the pixman ops from the profiles.
      */
     if (_csi_likely (_matching_images (surface, source))) {
-	cairo_surface_flush (surface);
-	memcpy (cairo_image_surface_get_data (surface),
-		cairo_image_surface_get_data (source),
-		cairo_image_surface_get_height (source) * cairo_image_surface_get_stride (source));
-	cairo_surface_mark_dirty (surface);
+	if (cairo_surface_get_reference_count (surface) == 1 &&
+	    cairo_surface_get_reference_count (source) == 1)
+	{
+	    _csi_peek_ostack (ctx, 0)->datum.surface = surface;
+	    _csi_peek_ostack (ctx, 1)->datum.surface = source;
+	}
+	else
+	{
+	    cairo_surface_flush (surface);
+	    memcpy (cairo_image_surface_get_data (surface),
+		    cairo_image_surface_get_data (source),
+		    cairo_image_surface_get_height (source) * cairo_image_surface_get_stride (source));
+	    cairo_surface_mark_dirty (surface);
+	}
     } else {
 	cairo_t *cr;