Correct logic for picking bluetooth local name (#102823)

* Correct logic for picking bluetooth local name

* make test more robust

---------

Co-authored-by: J. Nick Koston <nick@koston.org>

homeassistant/components/bluetooth/base_scanner.py

@@ -330,7 +330,7 @@ class BaseHaRemoteScanner(BaseHaScanner):
             prev_manufacturer_data = prev_advertisement.manufacturer_data
             prev_name = prev_device.name
 
-            if local_name and prev_name and len(prev_name) > len(local_name):
+            if prev_name and (not local_name or len(prev_name) > len(local_name)):
                 local_name = prev_name
 
             if service_uuids and service_uuids != prev_service_uuids:

tests/components/bluetooth/test_base_scanner.py

@@ -42,7 +42,10 @@ from . import (
 from tests.common import async_fire_time_changed, load_fixture
 
 
-async def test_remote_scanner(hass: HomeAssistant, enable_bluetooth: None) -> None:
+@pytest.mark.parametrize("name_2", [None, "w"])
+async def test_remote_scanner(
+    hass: HomeAssistant, enable_bluetooth: None, name_2: str | None
+) -> None:
     """Test the remote scanner base class merges advertisement_data."""
     manager = _get_manager()
 
@@ -61,12 +64,25 @@ async def test_remote_scanner(hass: HomeAssistant, enable_bluetooth: None) -> No
     )
     switchbot_device_2 = generate_ble_device(
         "44:44:33:11:23:45",
-        "w",
+        name_2,
         {},
         rssi=-100,
     )
     switchbot_device_adv_2 = generate_advertisement_data(
-        local_name="wohand",
+        local_name=name_2,
+        service_uuids=["00000001-0000-1000-8000-00805f9b34fb"],
+        service_data={"00000001-0000-1000-8000-00805f9b34fb": b"\n\xff"},
+        manufacturer_data={1: b"\x01", 2: b"\x02"},
+        rssi=-100,
+    )
+    switchbot_device_3 = generate_ble_device(
+        "44:44:33:11:23:45",
+        "wohandlonger",
+        {},
+        rssi=-100,
+    )
+    switchbot_device_adv_3 = generate_advertisement_data(
+        local_name="wohandlonger",
         service_uuids=["00000001-0000-1000-8000-00805f9b34fb"],
         service_data={"00000001-0000-1000-8000-00805f9b34fb": b"\n\xff"},
         manufacturer_data={1: b"\x01", 2: b"\x02"},
@@ -125,6 +141,15 @@ async def test_remote_scanner(hass: HomeAssistant, enable_bluetooth: None) -> No
         "00000001-0000-1000-8000-00805f9b34fb",
     }
 
+    # The longer name should be used
+    scanner.inject_advertisement(switchbot_device_3, switchbot_device_adv_3)
+    assert discovered_device.name == switchbot_device_3.name
+
+    # Inject the shorter name / None again to make
+    # sure we always keep the longer name
+    scanner.inject_advertisement(switchbot_device_2, switchbot_device_adv_2)
+    assert discovered_device.name == switchbot_device_3.name
+
     cancel()
     unsetup()