From d9a1434ae978465a016ec987094131ef6d325eaf Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Florian=20M=C3=BCllner?= <fmuellner@gnome.org>
Date: Mon, 9 Jul 2018 12:19:00 +0200
Subject: [PATCH] workspaceThumbnail: Don't keep stale clones in list

If a clone gets destroyed before the corresponding MetaWindow is
removed from the workspace, we will still find it in the list of
clones and try to destroy it again. Avoid the resulting warnings
by updating the list of clones immediately when a clone is destroyed.

https://bugzilla.gnome.org/show_bug.cgi?id=791233
---
 js/ui/workspaceThumbnail.js | 26 ++++++++++++++++----------
 1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/js/ui/workspaceThumbnail.js b/js/ui/workspaceThumbnail.js
index db0677006..68922c943 100644
--- a/js/ui/workspaceThumbnail.js
+++ b/js/ui/workspaceThumbnail.js
@@ -372,16 +372,9 @@ var WorkspaceThumbnail = new Lang.Class({
     },
 
     _doRemoveWindow(metaWin) {
-        // find the position of the window in our list
-        let index = this._lookupIndex (metaWin);
-
-        if (index == -1)
-            return;
-
-        let clone = this._windows[index];
-        this._windows.splice(index, 1);
-
-        clone.destroy();
+        let clone = this._removeWindowClone(metaWin);
+        if (clone)
+            clone.destroy();
     },
 
     _doAddWindow(metaWin) {
@@ -533,6 +526,9 @@ var WorkspaceThumbnail = new Lang.Class({
         clone.connect('drag-end', () => {
             Main.overview.endWindowDrag(clone.metaWindow);
         });
+        clone.actor.connect('destroy', () => {
+            this._removeWindowClone(clone.metaWindow);
+        });
         this._contents.add_actor(clone.actor);
 
         if (this._windows.length == 0)
@@ -545,6 +541,16 @@ var WorkspaceThumbnail = new Lang.Class({
         return clone;
     },
 
+    _removeWindowClone(metaWin) {
+        // find the position of the window in our list
+        let index = this._lookupIndex (metaWin);
+
+        if (index == -1)
+            return null;
+
+        return this._windows.splice(index, 1).pop();
+    },
+
     activate(time) {
         if (this.state > ThumbnailState.NORMAL)
             return;