[gtk+] mir: reconstruct surface if window is moved

[William Hua <williamhua src gnome org>]

commit bee39d2251e58a693e19db701e791098eefd4f23
Author: William Hua <william attente ca>
Date:   Mon Jan 26 18:29:07 2015 -0500

    mir: reconstruct surface if window is moved

 gdk/mir/gdkmirwindowimpl.c |   17 ++++++++++-------
 1 files changed, 10 insertions(+), 7 deletions(-)
---
diff --git a/gdk/mir/gdkmirwindowimpl.c b/gdk/mir/gdkmirwindowimpl.c
index 4e0503b..5ecec56 100644
--- a/gdk/mir/gdkmirwindowimpl.c
+++ b/gdk/mir/gdkmirwindowimpl.c
@@ -527,6 +527,7 @@ gdk_mir_window_impl_move_resize (GdkWindow *window,
   g_printerr ("\n");
   */
   GdkMirWindowImpl *impl = GDK_MIR_WINDOW_IMPL (window->impl);
+  gboolean recreate_surface = FALSE;
 
   /* Redraw parent where we moved from */
   if (should_render_in_parent (window))
@@ -540,10 +541,11 @@ gdk_mir_window_impl_move_resize (GdkWindow *window,
           window->x = x;
           window->y = y;
         }
-      else
+      else if (x != impl->transient_x || y != impl->transient_y)
         {
           impl->transient_x = x;
           impl->transient_y = y;
+          recreate_surface = TRUE;
         }
     }
 
@@ -553,14 +555,15 @@ gdk_mir_window_impl_move_resize (GdkWindow *window,
     /* We accept any resize */
     window->width = width;
     window->height = height;
-
-    if (impl->surface)
-      {
-        ensure_no_surface (window);
-        ensure_surface (window);
-      }
+    recreate_surface = TRUE;
   }
 
+  if (recreate_surface && impl->surface)
+    {
+      ensure_no_surface (window);
+      ensure_surface (window);
+    }
+
   /* Redraw parent where we moved to */
   if (should_render_in_parent (window))
     redraw_transient (window);