[gnome-shell] polkitAgent: Disconnect from user signals when closing dialogue

[Florian Müllner <fmuellner src gnome org>]

commit 21de3c327b9e5f4141723c15e75e52c206e71b53
Author: Philip Withnall <withnall endlessm com>
Date:   Fri Jan 18 13:22:33 2019 +0000

    polkitAgent: Disconnect from user signals when closing dialogue
    
    Otherwise the user object could outlive the dialogue, emit a subsequent
    signal, and the callback from that signal could reference finalised
    objects/widgets from the dialogue. The likely mechanism for the user
    outliving the dialogue is caching of user objects within
    libaccountsservice.
    
    This can be triggered by running `pkexec true` from a gnome-terminal
    window, then calling `pkill pkexec` from another terminal (on a
    different VT or via SSH). This causes the dialogue to be cancelled by
    polkitd.
    
    Signed-off-by: Philip Withnall <withnall endlessm com>
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/357

 js/ui/components/polkitAgent.js | 6 ++++++
 1 file changed, 6 insertions(+)
---
diff --git a/js/ui/components/polkitAgent.js b/js/ui/components/polkitAgent.js
index 7f38e122e..dee5f38b3 100644
--- a/js/ui/components/polkitAgent.js
+++ b/js/ui/components/polkitAgent.js
@@ -332,6 +332,12 @@ var AuthenticationDialog = new Lang.Class({
             Main.sessionMode.disconnect(this._sessionUpdatedId);
         this._sessionUpdatedId = 0;
 
+        if (this._user) {
+            this._user.disconnect(this._userLoadedId);
+            this._user.disconnect(this._userChangedId);
+            this._user = null;
+        }
+
         this._destroySession();
     },
 });