[gnome-shell] grabHelper: Ignore key focus changes when ungrabbing

[Jasper St. Pierre <jstpierre src gnome org>]

commit 3628c818856fb5e795258c9af39265263f83e588
Author: Jasper St. Pierre <jstpierre mecheye net>
Date:   Sat Feb 16 13:19:44 2013 -0500

    grabHelper: Ignore key focus changes when ungrabbing
    
    Calling onUngrab() may change key focus, either directly or
    indirectly (e.g. hiding the actor). Such key focus changes
    would cause an extra actor to be ungrabbed, so make sure to
    ignore such focus changes while we're ungrabbing.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=693975

 js/ui/grabHelper.js |   14 ++++++++++++++
 1 files changed, 14 insertions(+), 0 deletions(-)
---
diff --git a/js/ui/grabHelper.js b/js/ui/grabHelper.js
index e31cc2f..10e5979 100644
--- a/js/ui/grabHelper.js
+++ b/js/ui/grabHelper.js
@@ -35,6 +35,7 @@ const GrabHelper = new Lang.Class({
         this._keyFocusNotifyId = 0;
         this._focusWindowChangedId = 0;
         this._ignoreRelease = false;
+        this._isUngrabbingCount = 0;
 
         this._modalCount = 0;
         this._grabFocusCount = 0;
@@ -275,6 +276,14 @@ const GrabHelper = new Lang.Class({
         if (grabStackIndex < 0)
             return;
 
+        // We may get key focus changes when calling onUngrab, which
+        // would cause an extra ungrab() on the next actor in the
+        // stack, which is wrong. Ignore key focus changes during the
+        // ungrab, and restore the saved key focus ourselves afterwards.
+        // We use a count as ungrab() may be re-entrant, as onUngrab()
+        // may ungrab additional actors.
+        this._isUngrabbingCount++;
+
         let focus = global.stage.key_focus;
         let hadFocus = focus && this._isWithinGrabbedActor(focus);
 
@@ -306,6 +315,8 @@ const GrabHelper = new Lang.Class({
             if (poppedGrab.savedFocus)
                 poppedGrab.savedFocus.grab_key_focus();
         }
+
+        this._isUngrabbingCount--;
     },
 
     _onCapturedEvent: function(actor, event) {
@@ -348,6 +359,9 @@ const GrabHelper = new Lang.Class({
     },
 
     _onKeyFocusChanged: function() {
+        if (this._isUngrabbingCount > 0)
+            return;
+
         let focus = global.stage.key_focus;
         if (!focus || !this._isWithinGrabbedActor(focus))
             this.ungrab({ isUser: true });