From c57245b73c40f8095cb66e1e1d1773c05b3e2bde Mon Sep 17 00:00:00 2001
From: Matthias Clasen <mclasen@redhat.com>
Date: Sat, 18 Nov 2023 02:16:36 -0500
Subject: [PATCH] diff: Take above-ness into account

We need to include the full area if a subsurface
above-ness changes, since we only punch holes if
it is above.

Fixes: #6214
---
 gsk/gskrendernodeimpl.c | 46 +++++++++++++++++++++++++----------------
 1 file changed, 28 insertions(+), 18 deletions(-)

diff --git a/gsk/gskrendernodeimpl.c b/gsk/gskrendernodeimpl.c
index acc4b03875..9a0d765216 100644
--- a/gsk/gskrendernodeimpl.c
+++ b/gsk/gskrendernodeimpl.c
@@ -6717,27 +6717,37 @@ gsk_subsurface_node_diff (GskRenderNode  *node1,
 {
   GskSubsurfaceNode *self1 = (GskSubsurfaceNode *) node1;
   GskSubsurfaceNode *self2 = (GskSubsurfaceNode *) node2;
+  GskOffloadInfo *info1, *info2;
 
-  if (data->offload)
+  if (!data->offload)
     {
-      /* Include the full area if the offload status changed. */
-      if (gsk_offload_subsurface_was_offloaded (data->offload, self1->subsurface) !=
-          gsk_offload_subsurface_is_offloaded (data->offload, self1->subsurface))
-        {
-          gsk_render_node_diff_impossible (node1, node2, data);
-        }
-      else if (gsk_offload_subsurface_is_offloaded (data->offload, self1->subsurface))
-        {
-          if (!gsk_rect_equal (&node1->bounds, &node2->bounds))
-            gsk_render_node_diff_impossible (node1, node2, data);
-        }
-      else
-        {
-          gsk_render_node_data_diff (self1->child, self2->child, data);
-        }
+      gsk_render_node_data_diff (self1->child, self2->child, data);
+      return;
+    }
+
+  info1 = gsk_offload_get_subsurface_info (data->offload, self1->subsurface);
+  info2 = gsk_offload_get_subsurface_info (data->offload, self2->subsurface);
+
+  if (!info1 || !info2)
+    {
+      gsk_render_node_data_diff (self1->child, self2->child, data);
+      return;
+    }
+
+  if (info1->is_offloaded != info2->is_offloaded ||
+      info1->is_above != info2->is_above)
+    {
+      gsk_render_node_diff_impossible (node1, node2, data);
+    }
+  else if (info1->is_offloaded && !info1->is_above &&
+           !gsk_rect_equal (&info1->rect, &info2->rect))
+    {
+      gsk_render_node_diff_impossible (node1, node2, data);
+    }
+  else if (!info1->is_offloaded)
+    {
+      gsk_render_node_data_diff (self1->child, self2->child, data);
     }
-  else
-    gsk_render_node_data_diff (self1->child, self2->child, data);
 }
 
 static void