Fix MQTT threading bug (home-assistant#43667)

Author: emontnemery

homeassistant/components/mqtt/__init__.py

@@ -944,7 +944,7 @@ async def publish_birth_message(birth_message):
                 )
 
             birth_message = Message(**self.conf[CONF_BIRTH_MESSAGE])
-            self.hass.loop.create_task(publish_birth_message(birth_message))
+            self.hass.add_job(publish_birth_message(birth_message))
 
     def _mqtt_on_message(self, _mqttc, _userdata, msg) -> None:
         """Message received callback."""

tests/components/mqtt/test_init.py

@@ -638,8 +638,9 @@ async def test_restore_subscriptions_on_reconnect(hass, mqtt_client_mock, mqtt_m
     assert mqtt_client_mock.subscribe.call_count == 1
 
     mqtt_mock._mqtt_on_disconnect(None, None, 0)
-    mqtt_mock._mqtt_on_connect(None, None, None, 0)
-    await hass.async_block_till_done()
+    with patch("homeassistant.components.mqtt.DISCOVERY_COOLDOWN", 0):
+        mqtt_mock._mqtt_on_connect(None, None, None, 0)
+        await hass.async_block_till_done()
     assert mqtt_client_mock.subscribe.call_count == 2
 
 
@@ -671,8 +672,9 @@ async def test_restore_all_active_subscriptions_on_reconnect(
     assert mqtt_client_mock.unsubscribe.call_count == 0
 
     mqtt_mock._mqtt_on_disconnect(None, None, 0)
-    mqtt_mock._mqtt_on_connect(None, None, None, 0)
-    await hass.async_block_till_done()
+    with patch("homeassistant.components.mqtt.DISCOVERY_COOLDOWN", 0):
+        mqtt_mock._mqtt_on_connect(None, None, None, 0)
+        await hass.async_block_till_done()
 
     expected.append(call("test/state", 1))
     assert mqtt_client_mock.subscribe.mock_calls == expected