[gtk+] wayland: Keep last scale factor on surfaces after it left all outputs

[Matthias Clasen <matthiasc src gnome org>]

commit 665c3a2877043b7d8adfe51d220ac83a0bf54f5a
Author: Carlos Garnacho <carlosg gnome org>
Date:   Tue Nov 15 15:07:39 2016 +0100

    wayland: Keep last scale factor on surfaces after it left all outputs
    
    This can be triggered on workspace switches, and on hidpi results in
    the scale factor being reset to 1 while the window is not in the
    current workspace.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=774476

 gdk/wayland/gdkwindow-wayland.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/gdk/wayland/gdkwindow-wayland.c b/gdk/wayland/gdkwindow-wayland.c
index e7fdd47..010add3 100644
--- a/gdk/wayland/gdkwindow-wayland.c
+++ b/gdk/wayland/gdkwindow-wayland.c
@@ -1217,7 +1217,8 @@ surface_leave (void              *data,
 
   impl->display_server.outputs = g_slist_remove (impl->display_server.outputs, output);
 
-  window_update_scale (window);
+  if (impl->display_server.outputs)
+    window_update_scale (window);
 }
 
 static const struct wl_surface_listener surface_listener = {