[gnome-shell/gnome-3-28] windowManager: listen actively to windows being destroyed during WS switch

[Florian Müllner <fmuellner src gnome org>]

commit 09fbb4a127db2a3a3bfadf06d176f2645c5d93c8
Author: Carlos Garnacho <carlosg gnome org>
Date:   Thu Sep 6 21:50:21 2018 +0200

    windowManager: listen actively to windows being destroyed during WS switch
    
    Prevents gjs from dealing with already dispose()d objects.
    
    Closes: https://gitlab.gnome.org/GNOME/gnome-shell/issues/539
    
    (cherry-picked from b087752b5539a8cbb1d61979cb069aef8a3475be)

 js/ui/windowManager.js | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)
---
diff --git a/js/ui/windowManager.js b/js/ui/windowManager.js
index 8e7e7a6e5..49d70355c 100644
--- a/js/ui/windowManager.js
+++ b/js/ui/windowManager.js
@@ -1763,6 +1763,14 @@ var WindowManager = new Lang.Class({
             }
         }
 
+        for (let i = 0; i < switchData.windows.length; i++) {
+            let w = switchData.windows[i];
+
+            w.windowDestroyId = w.window.connect('destroy', () => {
+                switchData.windows.splice(switchData.windows.indexOf(w), 1);
+            });
+        }
+
         switchData.inGroup.set_position(-xDest, -yDest);
         switchData.inGroup.raise_top();
 
@@ -1793,8 +1801,8 @@ var WindowManager = new Lang.Class({
 
         for (let i = 0; i < switchData.windows.length; i++) {
                 let w = switchData.windows[i];
-                if (w.window.is_destroyed()) // Window gone
-                    continue;
+                w.window.disconnect(w.windowDestroyId);
+
                 if (w.window.get_parent() == switchData.outGroup) {
                     w.window.reparent(w.parent);
                     w.window.hide();