Fix is_matching in samsungtv config flow

homeassistant/components/samsungtv/config_flow.py

@@ -441,7 +441,7 @@ def _async_abort_if_host_already_in_progress(self) -> None:
 
     def is_matching(self, other_flow: Self) -> bool:
         """Return True if other_flow is matching this flow."""
-        return other_flow._host == self._host  # noqa: SLF001
+        return getattr(other_flow, "_host", None) == self._host
 
     @callback
     def _abort_if_manufacturer_is_not_samsung(self) -> None:

tests/components/samsungtv/test_config_flow.py

@@ -2143,3 +2143,39 @@ async def test_ssdp_update_mac(hass: HomeAssistant) -> None:
         # ensure mac was updated with new wifiMac value
         assert entry.data[CONF_MAC] == "aa:bb:cc:dd:ee:ff"
         assert entry.unique_id == "123"
+
+
+@pytest.mark.usefixtures("remote_websocket")
+async def test_dhcp_while_user_flow_pending(hass: HomeAssistant) -> None:
+    """Simulate pending user flow, then trigger DHCP before submit.
+
+    Covers https://github.com/home-assistant/core/issues/156591.
+    """
+    with patch(
+        "homeassistant.components.samsungtv.bridge.SamsungTVWSBridge.async_device_info",
+        return_value=None,  # Simulate device not connectable
+    ):
+        # Start user flow, which will show form (cannot connect)
+        result_user = await hass.config_entries.flow.async_init(
+            DOMAIN,
+            context={"source": config_entries.SOURCE_USER},
+        )
+    assert result_user["type"] == FlowResultType.FORM
+    assert result_user["step_id"] == "user"
+
+    # While user flow is pending (form shown), trigger DHCP flow
+    dhcp_data = DhcpServiceInfo(
+        ip="10.10.12.34", macaddress="aabbccddeeff", hostname="fake_hostname"
+    )
+    with patch(
+        "homeassistant.components.samsungtv.bridge.SamsungTVWSBridge.async_device_info",
+        return_value={
+            "device": {"modelName": "fake_model", "wifiMac": "aa:bb:cc:dd:ee:ff"}
+        },
+    ):
+        result_dhcp = await hass.config_entries.flow.async_init(
+            DOMAIN,
+            context={"source": config_entries.SOURCE_DHCP},
+            data=dhcp_data,
+        )
+    assert result_dhcp["type"] == FlowResultType.ABORT