Handle intended via_device missing in tellduslive (#178178)

homeassistant/components/tellduslive/entity.py

@@ -121,10 +121,11 @@ class TelldusLiveEntity(Entity):
             config_entry = self.platform.config_entry
             if TYPE_CHECKING:
                 assert config_entry
-            # The hub is registered in async_new_client before entities are added.
-            device_info["via_device_id"] = dr.async_get_device_id_by_identifier(
-                self.hass,
-                (DOMAIN, client),
-                config_entry_id=config_entry.entry_id,
+            # The hub is not registered when fetching the client list failed while
+            # device requests succeeded, so link only when the hub device exists.
+            hub_device = dr.async_get(self.hass).async_get_device_by_identifier(
+                (DOMAIN, client), config_entry.entry_id
             )
+            if hub_device is not None:
+                device_info["via_device_id"] = hub_device.id
         return device_info

tests/components/tellduslive/test_init.py

@@ -40,3 +40,35 @@ async def test_device_via_device_links(
     assert child_device.via_device_id == hub_device.id
 
     assert await hass.config_entries.async_unload(mock_config_entry.entry_id)
+
+
+async def test_device_added_without_hub(
+    hass: HomeAssistant,
+    device_registry: dr.DeviceRegistry,
+    mock_config_entry: MockConfigEntry,
+    mock_tellduslive: MagicMock,
+) -> None:
+    """Test a device is still added, unlinked, when its hub is not registered."""
+    # A failed clients/list request yields an empty hub list, so no hub is registered.
+    mock_tellduslive.get_clients.return_value = []
+    mock_config_entry.add_to_hass(hass)
+
+    assert await hass.config_entries.async_setup(mock_config_entry.entry_id)
+    await hass.data[NEW_CLIENT_TASK]
+    await hass.async_block_till_done()
+    assert mock_config_entry.state is ConfigEntryState.LOADED
+
+    assert (
+        device_registry.async_get_device_by_identifier(
+            (DOMAIN, HUB_ID), mock_config_entry.entry_id
+        )
+        is None
+    )
+
+    child_device = device_registry.async_get_device_by_identifier(
+        (DOMAIN, DEVICE_ID), mock_config_entry.entry_id
+    )
+    assert child_device is not None
+    assert child_device.via_device_id is None
+
+    assert await hass.config_entries.async_unload(mock_config_entry.entry_id)