fix: Stack-overflow during shutdown

pueue/src/daemon/process_handler/mod.rs

@@ -17,9 +17,13 @@ pub mod start;
 /// We don't have to pause any groups, as no new tasks will be spawned during shutdown anyway.
 /// Any groups with queued tasks, will be automatically paused on state-restoration.
 pub fn initiate_shutdown(settings: &Settings, state: &mut LockedState, shutdown: Shutdown) {
-    state.shutdown = Some(shutdown);
-
-    self::kill::kill(settings, state, TaskSelection::All, false, None);
+    // Only start shutdown if we aren't already in one.
+    // Otherwise, we might end up with an endless recursion as `kill` might fail and initiate shutdown
+    // once again.
+    if state.shutdown.is_none() {
+        state.shutdown = Some(shutdown);
+        self::kill::kill(settings, state, TaskSelection::All, false, None);
+    }
 }
 
 /// This is a small wrapper around the real platform dependant process handling logic