[gtk] broadway: Handle Cairo nodes with NULL surfaces

[Benjamin Otte <otte src gnome org>]

commit 6e15538328b8ac69d6c310724e1d2a15630dc16c
Author: Benjamin Otte <otte redhat com>
Date:   Wed May 29 05:41:53 2019 +0200

    broadway: Handle Cairo nodes with NULL surfaces

 gsk/broadway/gskbroadwayrenderer.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
---
diff --git a/gsk/broadway/gskbroadwayrenderer.c b/gsk/broadway/gskbroadwayrenderer.c
index 662ee64934..1dbfc9c11c 100644
--- a/gsk/broadway/gskbroadwayrenderer.c
+++ b/gsk/broadway/gskbroadwayrenderer.c
@@ -506,11 +506,13 @@ gsk_broadway_renderer_add_node (GskRenderer *renderer,
     case GSK_CAIRO_NODE:
       if (add_new_node (renderer, node, BROADWAY_NODE_TEXTURE))
         {
-          cairo_surface_t *surface = (cairo_surface_t *)gsk_cairo_node_peek_surface (node);
+          cairo_surface_t *surface = gsk_cairo_node_peek_surface (node);
           cairo_surface_t *image_surface = NULL;
           GdkTexture *texture;
           guint32 texture_id;
 
+          if (surface == NULL)
+            return;
           if (cairo_surface_get_type (surface) == CAIRO_SURFACE_TYPE_IMAGE)
             image_surface = cairo_surface_reference (surface);
           else