fix(discord): reuse existing auto-thread on create race

plugins/platforms/discord/adapter.py

@@ -4583,6 +4583,29 @@ async def _auto_create_thread(self, message: 'DiscordMessage') -> Optional[Any]:
             thread = await message.create_thread(name=thread_name, auto_archive_duration=1440)
             return thread
         except Exception as direct_error:
+            # If another bot/client won the race and already created the thread
+            # from this starter message, Discord rejects a second
+            # message.create_thread() call.  Reuse the existing thread instead
+            # of posting a new seed message, which would create a duplicate
+            # top-level post + duplicate thread.
+            existing_thread = getattr(message, "thread", None)
+            if existing_thread is not None:
+                return existing_thread
+            if self._client is not None:
+                try:
+                    existing_thread = self._client.get_channel(int(message.id))
+                    if existing_thread is None:
+                        existing_thread = await self._client.fetch_channel(int(message.id))
+                    if existing_thread is not None:
+                        return existing_thread
+                except Exception:
+                    logger.debug(
+                        "[%s] Could not resolve existing Discord thread for starter message %s",
+                        self.name,
+                        getattr(message, "id", "unknown"),
+                        exc_info=True,
+                    )
+
             display_name = getattr(getattr(message, "author", None), "display_name", None) or "unknown user"
             reason = f"Auto-threaded from mention by {display_name}"
             try:

scripts/release.py

@@ -45,6 +45,7 @@
 
 # Auto-extracted from noreply emails + manual overrides
 AUTHOR_MAP = {
+    "jeevesassistant00@gmail.com": "jeeves-assistant",  # PR #48685 (Discord existing-thread auto-thread race)
     "21178861+ScotterMonk@users.noreply.github.com": "ScotterMonk",  # PR #50145 salvage (cron output truncation: adapter-aware chunking, #50126)
     "rrandqua@gmail.com": "TutkuEroglu",  # PR #50481 salvage (AGENTS.md stale token-lock adapter path)
     "f@trycua.com": "f-trycua",  # PR #50507 salvage (cross-platform computer_use; supersedes #44221/#30660)

tests/gateway/test_discord_channel_controls.py

@@ -61,6 +61,7 @@ def __init__(self, channel_id: int = 1, name: str = "general", guild_name: str =
         self.name = name
         self.guild = SimpleNamespace(name=guild_name)
         self.topic = None
+        self.send = AsyncMock()
 
 
 class FakeThread:
@@ -281,6 +282,40 @@ async def test_no_thread_with_auto_thread_disabled_is_noop(adapter, monkeypatch)
     adapter.handle_message.assert_awaited_once()
 
 
+@pytest.mark.asyncio
+async def test_auto_create_thread_reuses_existing_message_thread(adapter):
+    """If another bot already created the starter thread, don't post a fallback seed."""
+    existing = FakeThread(channel_id=123, name="already-there")
+    channel = FakeTextChannel(channel_id=800)
+    message = make_message(channel=channel, content="Trip idea")
+    message.create_thread = AsyncMock(side_effect=RuntimeError("thread already exists"))
+    message.thread = existing
+
+    thread = await adapter._auto_create_thread(message)
+
+    assert thread is existing
+    channel.send.assert_not_awaited()
+
+
+@pytest.mark.asyncio
+async def test_auto_create_thread_fetches_existing_thread_by_starter_message_id(adapter):
+    """Discord message-backed thread IDs match the starter message ID."""
+    existing = FakeThread(channel_id=123, name="already-there")
+    channel = FakeTextChannel(channel_id=800)
+    message = make_message(channel=channel, content="Trip idea")
+    message.create_thread = AsyncMock(side_effect=RuntimeError("thread already exists"))
+    message.thread = None
+    adapter._client.get_channel = MagicMock(return_value=existing)
+    adapter._client.fetch_channel = AsyncMock()
+
+    thread = await adapter._auto_create_thread(message)
+
+    assert thread is existing
+    adapter._client.get_channel.assert_called_once_with(message.id)
+    adapter._client.fetch_channel.assert_not_awaited()
+    channel.send.assert_not_awaited()
+
+
 # ── config.py bridging ───────────────────────────────────────────────