[gnome-shell] windowManager: fix fullscreen clone being left around

[Cosimo Cecchi <cosimoc src gnome org>]

commit 83e7f6f496c76b0f777428524ecca00d6239031f
Author: Cosimo Cecchi <cosimoc gnome org>
Date:   Fri Oct 16 13:45:09 2015 -0700

    windowManager: fix fullscreen clone being left around
    
    If we get another effect on the same actor, we should make sure to
    remove the clone through the "overwrite" methods provided by Tweener, or
    there will be a race that might end up with a stray clone being left
    around.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=756714

 js/ui/windowManager.js |   15 ++++++++++++++-
 1 files changed, 14 insertions(+), 1 deletions(-)
---
diff --git a/js/ui/windowManager.js b/js/ui/windowManager.js
index c8996d8..32b8c0f 100644
--- a/js/ui/windowManager.js
+++ b/js/ui/windowManager.js
@@ -1296,7 +1296,10 @@ const WindowManager = new Lang.Class({
                            transition: 'easeOutQuad',
                            onComplete: this._sizeChangeWindowDone,
                            onCompleteScope: this,
-                           onCompleteParams: [shellwm, actor]
+                           onCompleteParams: [shellwm, actor],
+                           onOverwrite: this._sizeChangeWindowOverwritten,
+                           onOverwriteScope: this,
+                           onOverwriteParams: [shellwm, actor]
                          });
 
         // Now unfreeze actor updates, to get it to the new size.
@@ -1321,6 +1324,16 @@ const WindowManager = new Lang.Class({
         }
     },
 
+    _sizeChangeWindowOverwritten: function(shellwm, actor) {
+        if (this._removeEffect(this._resizing, actor)) {
+            let actorClone = actor.__fullscreenClone;
+            if (actorClone) {
+                actorClone.destroy();
+                delete actor.__fullscreenClone;
+            }
+        }
+    },
+
     _hasAttachedDialogs: function(window, ignoreWindow) {
         var count = 0;
         window.foreach_transient(function(win) {