From 27715f69329000dcea511318e67a4fb9eac037b2 Mon Sep 17 00:00:00 2001
From: James Mackay <NotExpectedYet>
Date: Fri, 9 Oct 2026 06:12:01 +0100
Subject: [PATCH] =?UTF-8?q?test(media=5Fplayer):=20MAC-collision=20pre-che?=
 =?UTF-8?q?ck=20migration=20branches=20=E2=80=94=20occupied=20MAC=20falls?=
 =?UTF-8?q?=20back=20to=20the=20entry=20id,=20free=20MAC=20taken=20(t26=20?=
 =?UTF-8?q?F4)?=
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Content-Type: text/plain; charset=UTF-8
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---
 tests/test_standalone_setup.py | 76 ++++++++++++++++++++++++++++++++++
 1 file changed, 76 insertions(+)

diff --git a/tests/test_standalone_setup.py b/tests/test_standalone_setup.py
index f84fbaa..8c126ac 100644
--- a/tests/test_standalone_setup.py
+++ b/tests/test_standalone_setup.py
@@ -532,6 +532,82 @@ class TestLegacyUniqueIdMigration:
 
         assert entry.unique_id == "aa:bb:cc:dd:ee:ff"  # MAC preferred
 
+    async def test_mac_collision_falls_back_to_entry_id(self, tmp_path):
+        """t26 F4: an existing entry owning the target MAC blocks the move."""
+        from types import SimpleNamespace as MigrationEntry
+
+        import entity_stublib
+
+        entity_stublib.load_entity_modules()
+        modules = sys.modules["nsh.media_player"]
+        entry = MigrationEntry(
+            entry_id="cfgid123",
+            data={CONF_ANDROIDTV_ENTITY: "media_player.shield"},
+            options={},
+            title="Shield",
+            unique_id="media_player.shield",
+            runtime_data=None,
+        )
+
+        class _Manager:
+            async def async_protocol_device_info(self):
+                return "Shield TV", "aa:bb:cc:dd:ee:ff"
+
+        entry.runtime_data = _Manager()
+
+        class _Entries:
+            entries = [
+                SimpleNamespace(entry_id="cfgid999", unique_id="aa:bb:cc:dd:ee:ff")
+            ]
+            updating_entry_calls: list = []
+
+            def async_update_entry(self, entry, **kwargs):
+                self.updating_entry_calls.append((entry, kwargs))
+                for key, value in kwargs.items():
+                    if key in ("options", "data", "unique_id"):
+                        setattr(entry, key, value)
+
+        entries = _Entries()
+        entries.hass = FakeHass(str(tmp_path))
+        hass = entries.hass
+        hass.config_entries = entries
+
+        await modules._migrate_legacy_unique_id(hass, entry)
+
+        # collision → the config-entry id is used instead
+        assert entry.unique_id == "cfgid123"
+
+    async def test_free_mac_is_taken_without_collision(self, tmp_path):
+        """t26 F4: no other entry holds the MAC → the MAC is used."""
+        from types import SimpleNamespace as MigrationEntry
+
+        import entity_stublib
+
+        entity_stublib.load_entity_modules()
+        modules = sys.modules["nsh.media_player"]
+        entry = MigrationEntry(
+            entry_id="cfgid123",
+            data={CONF_ANDROIDTV_ENTITY: "media_player.shield"},
+            options={},
+            title="Shield",
+            unique_id="media_player.shield",
+            runtime_data=None,
+        )
+
+        class _Manager:
+            async def async_protocol_device_info(self):
+                return "Shield TV", "aa:bb:cc:dd:ee:ff"
+
+        entry.runtime_data = _Manager()
+        hass = FakeHass(str(tmp_path))
+        hass.config_entries.entries = [
+            SimpleNamespace(entry_id="cfgid999", unique_id="other:mac")  # different MAC
+        ]
+
+        await modules._migrate_legacy_unique_id(hass, entry)
+
+        assert entry.unique_id == "aa:bb:cc:dd:ee:ff"  # free MAC taken
+
     async def test_never_runs_twice_for_a_migrated_entry(self, tmp_path):
         """The legacy pattern no longer matches after the one-time move."""
         import entity_stublib