[gnome-shell] messageList: stop syncing if closeButton has been destroyed

[Florian Müllner <fmuellner src gnome org>]

commit 87da623d86323a0744b8723e1991f053586defaf
Author: Marco Trevisan (Treviño) <mail 3v1n0 net>
Date:   Wed Jul 4 15:56:25 2018 +0200

    messageList: stop syncing if closeButton has been destroyed
    
    The _sync function for Message only updates the close button visibility,
    so we can safely stop doing that if the close button get get destroyed earlier
    (as it happens when clicking on it).
    
    https://bugzilla.gnome.org/show_bug.cgi?id=791233

 js/ui/messageList.js | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/js/ui/messageList.js b/js/ui/messageList.js
index 3b3c2b6df..547135a1f 100644
--- a/js/ui/messageList.js
+++ b/js/ui/messageList.js
@@ -363,7 +363,8 @@ var Message = new Lang.Class({
         this.setBody(body);
 
         this._closeButton.connect('clicked', this.close.bind(this));
-        this.actor.connect('notify::hover', this._sync.bind(this));
+        let actorHoverId = this.actor.connect('notify::hover', this._sync.bind(this));
+        this._closeButton.connect('destroy', this.actor.disconnect.bind(this.actor, actorHoverId));
         this.actor.connect('clicked', this._onClicked.bind(this));
         this.actor.connect('destroy', this._onDestroy.bind(this));
         this._sync();