[gnome-shell] dbusServices/extensions: Only allow one dialog at a time

[Marge Bot <marge-bot src gnome org>]

commit b93342f72e871dc8472a9e92b23b45e0e7ded282
Author: Florian Müllner <fmuellner gnome org>
Date:   Tue Oct 26 19:40:08 2021 +0200

    dbusServices/extensions: Only allow one dialog at a time
    
    Showing multiple preference dialogs at the same time (for instance
    by repeated `gnome-extensions prefs` calls) may or may not work as
    expected, depending on whether any of the dialogs is modal or not
    (read: opened via the Extensions app).
    
    The easiest way to address this is to disallow more than a single
    dialog at the time. It's arguably also the more predictable behavior,
    and means extensions don't have to deal with inconsistent state
    caused by multiple dialogs.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/4564
    
    Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2013>

 js/dbusServices/extensions/extensionsService.js | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)
---
diff --git a/js/dbusServices/extensions/extensionsService.js b/js/dbusServices/extensions/extensionsService.js
index 7fa32fe808..10743d4cc7 100644
--- a/js/dbusServices/extensions/extensionsService.js
+++ b/js/dbusServices/extensions/extensionsService.js
@@ -116,30 +116,37 @@ var ExtensionsService = class extends ServiceImplementation {
             if (this._handleError(invocation, error))
                 return;
 
+            if (this._prefsDialog) {
+                this._handleError(invocation,
+                    new Error('Already showing a prefs dialog'));
+                return;
+            }
+
             const [serialized] = res;
             const extension = ExtensionUtils.deserializeExtension(serialized);
 
-            const window = new ExtensionPrefsDialog(extension);
-            window.connect('realize', () => {
+            this._prefsDialog = new ExtensionPrefsDialog(extension);
+            this._prefsDialog.connect('realize', () => {
                 let externalWindow = null;
 
                 if (parentWindow)
                     externalWindow = Shew.ExternalWindow.new_from_handle(parentWindow);
 
                 if (externalWindow)
-                    externalWindow.set_parent_of(window.get_surface());
+                    externalWindow.set_parent_of(this._prefsDialog.get_surface());
             });
 
             if (options.modal)
-                window.modal = options.modal.get_boolean();
+                this._prefsDialog.modal = options.modal.get_boolean();
 
-            window.connect('close-request', () => {
+            this._prefsDialog.connect('close-request', () => {
+                delete this._prefsDialog;
                 this.release();
                 return false;
             });
             this.hold();
 
-            window.show();
+            this._prefsDialog.show();
 
             invocation.return_value(null);
         });