[gnome-shell] overview: Hide the overview on session mode hasOverview changes

[Florian Müllner <fmuellner src gnome org>]

commit b3999e40780de301e861b1cf59ba967b8bc9b721
Author: Jonas Dreßler <verdre v0yd nl>
Date:   Mon Feb 24 11:19:28 2020 +0100

    overview: Hide the overview on session mode hasOverview changes
    
    If the sessionMode does not allow to show the overview, we should also
    hide an already visible overview.
    
    This fixes a bug where, if the lockscreen was shown while the overview
    was visible, the Ctrl+Alt+Tab popup would allow navigating inside the
    overview because the overview actor is still mapped.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/1043

 js/ui/overview.js | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
---
diff --git a/js/ui/overview.js b/js/ui/overview.js
index 45d12340bc..4b30b6f878 100644
--- a/js/ui/overview.js
+++ b/js/ui/overview.js
@@ -270,7 +270,11 @@ var Overview = class {
     }
 
     _sessionUpdated() {
-        this.isDummy = !Main.sessionMode.hasOverview;
+        const { hasOverview } = Main.sessionMode;
+        if (!hasOverview)
+            this.hide();
+
+        this.isDummy = !hasOverview;
         this._createOverview();
     }