[gnome-shell/gnome-3-28] osdWindow: Disconnect signals on destroy

[Florian Müllner <fmuellner src gnome org>]

commit a5b36fc7f4613eb0007f974832575e4d3683e79a
Author: Florian Müllner <fmuellner gnome org>
Date:   Sun Sep 23 03:06:21 2018 +0200

    osdWindow: Disconnect signals on destroy
    
    Since we started to show OSD windows on all monitors, OSD windows are
    destroyed when the corresponding monitor is disconnected. We shouldn't
    leave any signal handlers around in that case - they prevent the object
    from being garbage collected, and trigger warnings for accessing proper-
    ties of invalidated GObjects.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/issues/602

 js/ui/osdWindow.js | 23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)
---
diff --git a/js/ui/osdWindow.js b/js/ui/osdWindow.js
index a73912413..97e0498a7 100644
--- a/js/ui/osdWindow.js
+++ b/js/ui/osdWindow.js
@@ -108,15 +108,30 @@ var OsdWindow = new Lang.Class({
         this._hideTimeoutId = 0;
         this._reset();
 
-        Main.layoutManager.connect('monitors-changed',
-                                   this._relayout.bind(this));
+        this.actor.connect('destroy', this._onDestroy.bind(this));
+
+        this._monitorsChangedId =
+            Main.layoutManager.connect('monitors-changed',
+                                       this._relayout.bind(this));
         let themeContext = St.ThemeContext.get_for_stage(global.stage);
-        themeContext.connect('notify::scale-factor',
-                             this._relayout.bind(this));
+        this._scaleChangedId =
+            themeContext.connect('notify::scale-factor',
+                                 this._relayout.bind(this));
         this._relayout();
         Main.uiGroup.add_child(this.actor);
     },
 
+    _onDestroy() {
+        if (this._monitorsChangedId)
+            Main.layoutManager.disconnect(this._monitorsChangedId);
+        this._monitorsChangedId = 0;
+
+        let themeContext = St.ThemeContext.get_for_stage(global.stage);
+        if (this._scaleChangedId)
+            themeContext.disconnect(this._scaleChangedId);
+        this._scaleChangedId = 0;
+    },
+
     setIcon(icon) {
         this._icon.gicon = icon;
     },