From e2429a26e0d3d039e6c8fb49d93e21382d4ec72b Mon Sep 17 00:00:00 2001
From: novax635 <novax635@gmail.com>
Date: Fri, 24 Apr 2026 12:28:14 +0300
Subject: [PATCH] fix(gateway): avoid threadless mirror session contamination

---
 gateway/mirror.py            |  2 ++
 tests/gateway/test_mirror.py | 57 ++++++++++++++++++++++++++++++++++++
 2 files changed, 59 insertions(+)

diff --git a/gateway/mirror.py b/gateway/mirror.py
index 0312424f1..8e21b8d9a 100644
--- a/gateway/mirror.py
+++ b/gateway/mirror.py
@@ -94,6 +94,8 @@ def _find_session_id(platform: str, chat_id: str, thread_id: Optional[str] = Non
         origin_chat_id = str(origin.get("chat_id", ""))
         if origin_chat_id == str(chat_id):
             origin_thread_id = origin.get("thread_id")
+            if thread_id is None and origin_thread_id is not None:
+                continue
             if thread_id is not None and str(origin_thread_id or "") != str(thread_id):
                 continue
             updated = entry.get("updated_at", "")
diff --git a/tests/gateway/test_mirror.py b/tests/gateway/test_mirror.py
index 427e720cd..074eca064 100644
--- a/tests/gateway/test_mirror.py
+++ b/tests/gateway/test_mirror.py
@@ -77,6 +77,46 @@ class TestFindSessionId:
 
         assert result == "sess_topic_a"
 
+    def test_threadless_lookup_skips_threaded_sessions(self, tmp_path):
+        sessions_dir, index_file = _setup_sessions(tmp_path, {
+            "topic_a": {
+                "session_id": "sess_topic_a",
+                "origin": {"platform": "telegram", "chat_id": "-1001", "thread_id": "10"},
+                "updated_at": "2026-01-01T00:00:00",
+            },
+            "topic_b": {
+                "session_id": "sess_topic_b",
+                "origin": {"platform": "telegram", "chat_id": "-1001", "thread_id": "11"},
+                "updated_at": "2026-02-01T00:00:00",
+            },
+        })
+
+        with patch.object(mirror_mod, "_SESSIONS_DIR", sessions_dir), \
+             patch.object(mirror_mod, "_SESSIONS_INDEX", index_file):
+            result = _find_session_id("telegram", "-1001")
+
+        assert result is None
+
+    def test_threadless_lookup_can_match_non_thread_session(self, tmp_path):
+        sessions_dir, index_file = _setup_sessions(tmp_path, {
+            "group": {
+                "session_id": "sess_group",
+                "origin": {"platform": "telegram", "chat_id": "-1001"},
+                "updated_at": "2026-01-01T00:00:00",
+            },
+            "topic": {
+                "session_id": "sess_topic",
+                "origin": {"platform": "telegram", "chat_id": "-1001", "thread_id": "11"},
+                "updated_at": "2026-02-01T00:00:00",
+            },
+        })
+
+        with patch.object(mirror_mod, "_SESSIONS_DIR", sessions_dir), \
+             patch.object(mirror_mod, "_SESSIONS_INDEX", index_file):
+            result = _find_session_id("telegram", "-1001")
+
+        assert result == "sess_group"
+
     def test_no_match_returns_none(self, tmp_path):
         sessions_dir, index_file = _setup_sessions(tmp_path, {
             "sess": {
@@ -189,6 +229,23 @@ class TestMirrorToSession:
         assert (sessions_dir / "sess_topic_a.jsonl").exists()
         assert not (sessions_dir / "sess_topic_b.jsonl").exists()
 
+    def test_threadless_mirror_does_not_write_to_threaded_session(self, tmp_path):
+        sessions_dir, index_file = _setup_sessions(tmp_path, {
+            "topic": {
+                "session_id": "sess_topic",
+                "origin": {"platform": "telegram", "chat_id": "-1001", "thread_id": "10"},
+                "updated_at": "2026-01-01T00:00:00",
+            },
+        })
+
+        with patch.object(mirror_mod, "_SESSIONS_DIR", sessions_dir), \
+             patch.object(mirror_mod, "_SESSIONS_INDEX", index_file), \
+             patch("gateway.mirror._append_to_sqlite"):
+            result = mirror_to_session("telegram", "-1001", "Hello group!", source_label="cron")
+
+        assert result is False
+        assert not (sessions_dir / "sess_topic.jsonl").exists()
+
     def test_no_matching_session(self, tmp_path):
         sessions_dir, index_file = _setup_sessions(tmp_path, {})