wayland: Don't overwrite surface offsets

The intention when the offset request was added to protocol was
that the attach request in a new enough protocol version should
require dx/dy to be zero, but ignore them otherwise.

The current code checks for 0, but then overwrites the existing
dx/dy with it, which renders an earlier wl_surface_offset() call
ineffective.

Fixes: #2622
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2843>


(cherry picked from commit ea373cb0590dbf5f857f6d96b10759f005b4fc93)

1 files changed, 13 insertions, 8 deletions

diff --git a/src/wayland/meta-wayland-surface.c b/src/wayland/meta-wayland-surface.c
index e8fb8fd08..d0ab61e65 100644
--- a/src/wayland/meta-wayland-surface.c
+++ b/src/wayland/meta-wayland-surface.c
@@ -1062,19 +1062,24 @@ wl_surface_attach (struct wl_client   *client,
     }
 
   if (wl_resource_get_version (surface_resource) >=
-      WL_SURFACE_OFFSET_SINCE_VERSION &&
-      (dx != 0 || dy != 0))
+      WL_SURFACE_OFFSET_SINCE_VERSION)
     {
-      wl_resource_post_error (surface_resource,
-                              WL_SURFACE_ERROR_INVALID_OFFSET,
-                              "Attaching with an offset is no longer allowed");
-      return;
+      if (dx != 0 || dy != 0)
+        {
+          wl_resource_post_error (surface_resource,
+                                  WL_SURFACE_ERROR_INVALID_OFFSET,
+                                  "Attaching with an offset is no longer allowed");
+          return;
+        }
+    }
+  else
+    {
+      pending->dx = dx;
+      pending->dy = dy;
     }
 
   pending->newly_attached = TRUE;
   pending->buffer = buffer;
-  pending->dx = dx;
-  pending->dy = dy;
 
   if (buffer)
     {