[polari] roomList: Disconnect window signals

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

commit bf3593701463c0829c3b8b62293b65c158ad1ca2
Author: Florian Müllner <fmuellner gnome org>
Date:   Mon Jul 26 21:04:56 2021 +0200

    roomList: Disconnect window signals
    
    So far we have just assumed that the toplevel window no longer
    emits any signals during destructions. We should properly clean
    up after ourselves instead.
    
    Part-of: <https://gitlab.gnome.org/GNOME/polari/-/merge_requests/230>

 src/roomList.js | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)
---
diff --git a/src/roomList.js b/src/roomList.js
index 14ba1fb9..fd6ff396 100644
--- a/src/roomList.js
+++ b/src/roomList.js
@@ -615,11 +615,21 @@ class RoomList extends Gtk.ListBox {
         super.vfunc_realize();
 
         const toplevel = this.get_root();
-        toplevel.connect('notify::active-room',
-            this._activeRoomChanged.bind(this));
+        this._toplevelSignals = [
+            toplevel.connect('notify::active-room',
+                () => this._activeRoomChanged()),
+        ];
         this._activeRoomChanged();
     }
 
+    vfunc_unrealize() {
+        super.vfunc_unrealize();
+
+        const toplevel = this.get_root();
+        this._toplevelSignals.forEach(id => toplevel.disconnect(id));
+        this._toplevelSignals = [];
+    }
+
     _rowToRoomIndex(index) {
         let placeholders = [...this._placeholders.values()];
         let nBefore = placeholders.filter(p => p.get_index() < index).length;