[gnome-shell] system: Emulate click action button release

[Florian Müllner <fmuellner src gnome org>]

commit 2339c39ae6cfa16e6440c6c06df38ca17e1586d9
Author: Florian Müllner <fmuellner gnome org>
Date:   Fri Jun 16 17:08:07 2017 +0200

    system: Emulate click action button release
    
    Since commit 2c070d38, we add a ClickAction to the visible AltSwitcher
    button to track long-presses. As a result, we now have two components
    that will grab and ungrab the pointer for the button, so to make sure
    we don't end up with a stuck grab, we need to release the second's
    component grab when the first activates.
    
    Currently we only drop the StButton grab on long-press, we also need
    to cancel any initiated long-press on click.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=781738

 js/ui/status/system.js |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)
---
diff --git a/js/ui/status/system.js b/js/ui/status/system.js
index 92ccf4c..8f99865 100644
--- a/js/ui/status/system.js
+++ b/js/ui/status/system.js
@@ -42,9 +42,15 @@ const AltSwitcher = new Lang.Class({
     _init: function(standard, alternate) {
         this._standard = standard;
         this._standard.connect('notify::visible', Lang.bind(this, this._sync));
+        if (this._standard instanceof St.Button)
+            this._standard.connect('clicked',
+                                   () => { this._clickAction.release(); });
 
         this._alternate = alternate;
         this._alternate.connect('notify::visible', Lang.bind(this, this._sync));
+        if (this._alternate instanceof St.Button)
+            this._alternate.connect('clicked',
+                                    () => { this._clickAction.release(); });
 
         this._capturedEventId = global.stage.connect('captured-event', Lang.bind(this, 
this._onCapturedEvent));