Guard shutdown() for STOPPING/CLOSE and unload host early in stop()

Move host.unload() before Stage 1 in stop() so the shutdown monitor
task is cancelled before infrastructure teardown begins. This prevents
a race where the monitor could react to PrepareForShutdown after
stop() has already started tearing down.

For the remaining edge case where shutdown() is called while stop()
is running, log a warning and return immediately instead of awaiting
the shutdown event (which would deadlock since stop() never sets it).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

supervisor/core.py

@@ -315,6 +315,9 @@ class Core(CoreSysAttributes):
         # don't process scheduler anymore
         await self.set_state(CoreState.STOPPING)
 
+        # Cancel shutdown monitor task before tearing down infrastructure
+        await self.sys_host.unload()
+
         # Stage 1
         try:
             async with asyncio.timeout(10):
@@ -341,7 +344,6 @@ class Core(CoreSysAttributes):
                             self.sys_websession.close(),
                             self.sys_ingress.unload(),
                             self.sys_hardware.unload(),
-                            self.sys_host.unload(),
                             self.sys_dbus.unload(),
                         )
                     ]
@@ -359,7 +361,13 @@ class Core(CoreSysAttributes):
         Reentrant: if a shutdown is already in progress, subsequent calls
         await completion of the existing shutdown rather than starting a second one.
         """
-        if self.state in (CoreState.SHUTDOWN, CoreState.STOPPING, CoreState.CLOSE):
+        # Supervisor is already tearing down, no point running shutdown
+        if self.state in (CoreState.STOPPING, CoreState.CLOSE):
+            _LOGGER.warning("Ignoring shutdown request, Supervisor is already stopping")
+            return
+
+        # Another shutdown is in progress, wait for it to complete
+        if self.state == CoreState.SHUTDOWN:
             await self._shutdown_event.wait()
             return
 

tests/test_core.py

@@ -211,3 +211,19 @@ async def test_shutdown_event_reset_between_cycles(coresys: CoreSys):
 
     assert second_entered
     assert coresys.core._shutdown_event.is_set()
+
+
+@pytest.mark.parametrize(
+    "state", [CoreState.STOPPING, CoreState.CLOSE], ids=["stopping", "close"]
+)
+async def test_shutdown_ignored_during_stop(
+    coresys: CoreSys, caplog: pytest.LogCaptureFixture, state: CoreState
+):
+    """Test that shutdown is ignored when Supervisor is already stopping."""
+    await coresys.core.set_state(state)
+
+    with patch.object(coresys.addons, "shutdown") as mock_addon_shutdown:
+        await coresys.core.shutdown()
+
+    mock_addon_shutdown.assert_not_called()
+    assert "Ignoring shutdown request, Supervisor is already stopping" in caplog.text