From 77a956873a1992e070ebeb2495e48a901a64610a Mon Sep 17 00:00:00 2001
From: Michael Webster <miketwebster@gmail.com>
Date: Wed, 21 May 2025 09:33:14 -0400
Subject: [PATCH] polkitAuthenticationAgent.js: Ensure Cinnamon is part of the
 correct login session when registering.

Compare Cinnamon's session id with cinnamon-session's (which
should never change), and have cinnamon-session restart us if
there is a mismatch.

Ref: #12669, #12728.

See: https://github.com/linuxmint/cinnamon-session/pull/184.
---
 js/misc/gnomeSession.js                    |  2 ++
 js/ui/polkitAuthenticationAgent.js         | 22 ++++++++++++++++++++--
 src/cinnamon-polkit-authentication-agent.c |  7 ++++++-
 src/cinnamon-polkit-authentication-agent.h |  2 +-
 4 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/js/misc/gnomeSession.js b/js/misc/gnomeSession.js
index c942dd9955..7564b92f29 100644
--- a/js/misc/gnomeSession.js
+++ b/js/misc/gnomeSession.js
@@ -75,6 +75,7 @@ var SessionManagerIface = '\
        <method name="GetInhibitors"> \
            <arg type="ao" name="inhibitors" direction="out"/> \
        </method> \
+       <method name="RestartCinnamonLauncher" /> \
        <signal name="InhibitorAdded"> \
            <arg type="o" name="id" direction="out"/> \
        </signal> \
@@ -82,6 +83,7 @@ var SessionManagerIface = '\
            <arg type="o" name="id" direction="out"/> \
        </signal> \
        <property name="InhibitedActions" type="u" access="read"/> \
+       <property name="SessionId" type="s" access="read"/> \
     </interface> \
 </node>';
 
diff --git a/js/ui/polkitAuthenticationAgent.js b/js/ui/polkitAuthenticationAgent.js
index d60e73eb31..44b445223c 100644
--- a/js/ui/polkitAuthenticationAgent.js
+++ b/js/ui/polkitAuthenticationAgent.js
@@ -32,6 +32,8 @@ const GLib = imports.gi.GLib;
 const Mainloop = imports.mainloop;
 const Polkit = imports.gi.Polkit;
 const PolkitAgent = imports.gi.PolkitAgent;
+const GnomeSession = imports.misc.gnomeSession;
+const Meta = imports.gi.Meta;
 
 const Dialog = imports.ui.dialog;
 const Main = imports.ui.main;
@@ -551,9 +553,25 @@ var AuthenticationAgent = class {
         this._native.connect('cancel', this._onCancel.bind(this));
         // TODO - maybe register probably should wait until later, especially at first login?
         try {
-            this._native.register();
+            const session = new GnomeSession.SessionManager();
+            const csSessionId = session.SessionId;
+
+            let procSessionId = this._native.register();
+            if (!Meta.is_wayland_compositor() && procSessionId !== csSessionId) {
+                global.logWarning("Unable to register as the polkit agent for login session '%s'. Cinnamon is running under '%s'"
+                                  .format(csSessionId, procSessionId));
+                this._native.unregister();
+                this._native = null;
+
+                // Starting cinnamon over SSH can be useful when debugging and profiling. Provide a way to prevent a restart.
+                if (!GLib.getenv("CINNAMON_ALLOW_SSH")) {
+                    global.logWarning('Restarting Cinnamon in 5 seconds.');
+                    GLib.timeout_add_seconds(GLib.PRIORITY_DEFAULT, 5, () => session.RestartCinnamonLauncherRemote())
+                    return;
+                }
+            }
         } catch(e) {
-            global.logWarning('Failed to register Polkit Agent');
+            global.log('Failed to register Polkit Agent', e);
         }
         this._currentDialog = null;
     }
diff --git a/src/cinnamon-polkit-authentication-agent.c b/src/cinnamon-polkit-authentication-agent.c
index 945aa586c3..6c9cb2725b 100644
--- a/src/cinnamon-polkit-authentication-agent.c
+++ b/src/cinnamon-polkit-authentication-agent.c
@@ -87,12 +87,14 @@ cinnamon_polkit_authentication_agent_init (CinnamonPolkitAuthenticationAgent *ag
 {
 }
 
-void
+gchar *
 cinnamon_polkit_authentication_agent_register (CinnamonPolkitAuthenticationAgent *agent,
                                             GError                        **error_out)
 {
   GError *error = NULL;
   PolkitSubject *subject;
+  gchar *session_id = NULL;
+
   subject = polkit_unix_session_new_for_process_sync (getpid (),
                                                       NULL, /* GCancellable* */
                                                       &error);
@@ -104,6 +106,7 @@ cinnamon_polkit_authentication_agent_register (CinnamonPolkitAuthenticationAgent
       goto out;
     }
 
+  session_id = g_strdup (polkit_unix_session_get_session_id (POLKIT_UNIX_SESSION (subject)));
   agent->handle = polkit_agent_listener_register (POLKIT_AGENT_LISTENER (agent),
                                                   POLKIT_AGENT_REGISTER_FLAGS_NONE,
                                                   subject,
@@ -117,6 +120,8 @@ cinnamon_polkit_authentication_agent_register (CinnamonPolkitAuthenticationAgent
 
   if (subject != NULL)
     g_object_unref (subject);
+
+  return session_id;
 }
 
 static void
diff --git a/src/cinnamon-polkit-authentication-agent.h b/src/cinnamon-polkit-authentication-agent.h
index 5fbbeefd6d..85a4a794ce 100644
--- a/src/cinnamon-polkit-authentication-agent.h
+++ b/src/cinnamon-polkit-authentication-agent.h
@@ -27,7 +27,7 @@ CinnamonPolkitAuthenticationAgent *cinnamon_polkit_authentication_agent_new (voi
 
 void                            cinnamon_polkit_authentication_agent_complete (CinnamonPolkitAuthenticationAgent *agent,
                                                                             gboolean                        dismissed);
-void                            cinnamon_polkit_authentication_agent_register (CinnamonPolkitAuthenticationAgent *agent,
+gchar *                         cinnamon_polkit_authentication_agent_register (CinnamonPolkitAuthenticationAgent *agent,
                                                                             GError                        **error_out);
 void                            cinnamon_polkit_authentication_agent_unregister (CinnamonPolkitAuthenticationAgent *agent);