From 8645007bffb844e6d35d19e902f0cce380233b40 Mon Sep 17 00:00:00 2001
From: Leonhard <106322251+leolost2605@users.noreply.github.com>
Date: Tue, 28 May 2024 20:01:43 +0200
Subject: [PATCH] Avoid ending our own process (#1919)

---
 src/Dialogs.vala                    | 12 ++++++++++++
 src/ShellClients/ManagedClient.vala | 15 +++++++++++++--
 2 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/src/Dialogs.vala b/src/Dialogs.vala
index 2f382674..658f9cb1 100644
--- a/src/Dialogs.vala
+++ b/src/Dialogs.vala
@@ -172,6 +172,18 @@ namespace Gala {
                 return;
             }
 
+            try {
+                var our_pid = new Credentials ().get_unix_pid ();
+                if (our_pid == window.get_pid ()) {
+                    critical ("We have an unresponsive window somewhere. Mutter wants to end its own process. Don't let it.");
+                    // In all seriousness this sounds bad, but can happen if one of our WaylandClients gets unresponsive.
+                    on_response (1);
+                    return;
+                }
+            } catch (Error e) {
+                warning ("Failed to safeguard kill pid: %s", e.message);
+            }
+
             base.show ();
         }
 
diff --git a/src/ShellClients/ManagedClient.vala b/src/ShellClients/ManagedClient.vala
index d354fc46..6d3cf1ab 100644
--- a/src/ShellClients/ManagedClient.vala
+++ b/src/ShellClients/ManagedClient.vala
@@ -18,6 +18,8 @@ public class Gala.ManagedClient : Object {
 
     public Meta.WaylandClient? wayland_client { get; private set; }
 
+    private Subprocess? subprocess;
+
     public ManagedClient (Meta.Display display, string[] args) {
         Object (display: display, args: args);
     }
@@ -29,6 +31,15 @@ public class Gala.ManagedClient : Object {
             display.window_created.connect ((window) => {
                 if (wayland_client != null && wayland_client.owns_window (window)) {
                     window_created (window);
+
+                    // We have to manage is alive manually since windows created by WaylandClients have our pid
+                    // and we don't want to end our own process
+                    window.notify["is-alive"].connect (() => {
+                        if (!window.is_alive && subprocess != null) {
+                            subprocess.force_exit ();
+                            warning ("WaylandClient window became unresponsive, killing the client.");
+                        }
+                    });
                 }
             });
         } else {
@@ -44,7 +55,7 @@ public class Gala.ManagedClient : Object {
 #else
             wayland_client = new Meta.WaylandClient (subprocess_launcher);
 #endif
-            var subprocess = wayland_client.spawnv (display, args);
+            subprocess = wayland_client.spawnv (display, args);
 
             yield subprocess.wait_async ();
 
@@ -61,7 +72,7 @@ public class Gala.ManagedClient : Object {
 
     private async void start_x () {
         try {
-            var subprocess = new Subprocess.newv (args, NONE);
+            subprocess = new Subprocess.newv (args, NONE);
             yield subprocess.wait_async ();
 
             //Restart the daemon if it crashes