breakManager: Fix a potential null object dereference

There’s no `else` branch above, so it’s possible for
`this._notification` to be `null` at the bottom of the function
(especially if the user has explicitly closed the previous
notification), so handle that.

Signed-off-by: Philip Withnall <pwithnall@gnome.org>
Helps: https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/8280
Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/3687>

diff --git a/js/misc/breakManager.js b/js/misc/breakManager.js
index 42e7c35696ec4279f8ae3b23f11b0c8a10c66330..371201a7a2c86c37906b104b13483f8cbee397dc 100644 (file)
--- a/js/misc/breakManager.js
+++ b/js/misc/breakManager.js
@@ -1278,8 +1278,11 @@ class BreakNotificationSource extends GObject.Object {
                 this._scheduleUpdateState(updateTimeoutSeconds);
             }
 
-            this._notification.urgency = this._urgencyForBreakType(this._manager.currentBreakType);
-            this._source.addNotification(this._notification);
+            if (this._notification) {
+                this._notification.urgency = this._urgencyForBreakType(this._manager.currentBreakType);
+                this._source.addNotification(this._notification);
+            }
+
             break;
         }