[gnome-shell] closeDialog: Remove transitions before resetting dialog

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 08203c9c1e021da8fb212ae6e1ca1c3704a3e91d
Author: Florian Müllner <fmuellner gnome org>
Date:   Sun Mar 22 00:18:13 2020 +0100

    closeDialog: Remove transitions before resetting dialog
    
    On X11, _onFocusChanged() updates the input region, as well as the
    reactive-ness of the dialog's buttons.
    
    That method is not only used as signal handlers (which are correctly
    disconnected when the dialog is hidden), it also runs when the "show"
    transition completes.
    
    That's a problem if the transition is still ongoing when the dialog is
    hidden, as it will then only complete when it is replaced by the "hide"
    transition, after the this._dialog has been reset to null, and trying
    to access the dialog's buttons results in an error.
    
    Avoid this by explicitly removing all transition on hide before
    resetting the dialog.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/issues/2467

 js/ui/closeDialog.js | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/js/ui/closeDialog.js b/js/ui/closeDialog.js
index 01799bd4ce..63a0bcfcf8 100644
--- a/js/ui/closeDialog.js
+++ b/js/ui/closeDialog.js
@@ -188,6 +188,8 @@ var CloseDialog = GObject.registerClass({
         global.stage.disconnect(this._keyFocusChangedId);
         this._keyFocusChangedId = 0;
 
+        this._dialog._dialog.remove_all_transitions();
+
         let dialog = this._dialog;
         this._dialog = null;
         this._removeWindowEffect();