Fix session title refinement after optimistic save

backend/api/server.py

@@ -3913,6 +3913,8 @@ def _read_session_title(directory: Path, session_id: str | None) -> str | None:
     except FileNotFoundError:
         return None
     metadata = stored.session_metadata or {}
+    if metadata.get('title_source') == 'first_message':
+        return None
     title = metadata.get('title')
     if isinstance(title, str) and title.strip():
         return title.strip()

tests/test_gui_server.py

@@ -12,6 +12,7 @@ from __future__ import annotations
 import tempfile
 import unittest
 import json
+from dataclasses import replace
 from pathlib import Path
 from unittest.mock import patch
 
@@ -24,6 +25,7 @@ from backend.api.server import (
     _derive_initial_session_title,
     _ensure_session_title,
     _generate_session_title,
+    _read_session_title,
     _runtime_event_stage,
     _save_in_progress_session,
     _sanitize_stored_session_for_resume,
@@ -795,26 +797,29 @@ class GuiServerTests(unittest.TestCase):
     def test_update_session_title(self) -> None:
         with tempfile.TemporaryDirectory() as d:
             root = Path(d)
-            client, _ = _build_client(root)
+            client, state = _build_client(root)
             session_root = root / 'accounts' / 'alice' / 'sessions'
-            nested = session_root / 'same-id'
-            nested.mkdir(parents=True)
-            session_file = nested / 'session.json'
-            session_file.write_text(
-                json.dumps({'session_id': 'same-id', 'messages': []}),
-                encoding='utf-8',
+            session_id = 'same-id'
+            agent = state.agent_for('alice', session_id)
+            _save_in_progress_session(
+                directory=session_root,
+                agent=agent,
+                session_id=session_id,
+                prompt='帮我分析数据。',
             )
 
             response = client.patch(
-                '/api/sessions/same-id',
+                f'/api/sessions/{session_id}',
                 params={'account_id': 'alice'},
                 json={'title': ' 手动标题 '},
             )
             self.assertEqual(response.status_code, 200)
             self.assertEqual(response.json()['title'], '手动标题')
-            data = json.loads(session_file.read_text(encoding='utf-8'))
-            self.assertEqual(data['title'], '手动标题')
-            self.assertEqual(data['title_source'], 'manual')
+            metadata = load_agent_session(
+                session_id, directory=session_root
+            ).session_metadata or {}
+            self.assertEqual(metadata['title'], '手动标题')
+            self.assertEqual(metadata['title_source'], 'manual')
 
     def test_in_progress_session_writes_first_message_title(self) -> None:
         with tempfile.TemporaryDirectory() as d:
@@ -834,8 +839,26 @@ class GuiServerTests(unittest.TestCase):
             session_file = directory / session_id / 'session.json'
             data = json.loads(session_file.read_text(encoding='utf-8'))
             self.assertTrue(title.startswith('帮我分析一下线上 router'))
-            self.assertEqual(data['title'], title)
-            self.assertEqual(data['title_source'], 'first_message')
+            metadata = data['session_metadata']
+            self.assertEqual(metadata['title'], title)
+            self.assertEqual(metadata['title_source'], 'first_message')
+
+    def test_first_message_title_is_not_preserved_as_previous_title(self) -> None:
+        with tempfile.TemporaryDirectory() as d:
+            root = Path(d)
+            _, state = _build_client(root)
+            session_id = 'first-title-previous'
+            directory = state.account_paths('alice')['sessions']
+            agent = state.agent_for('alice', session_id)
+
+            _save_in_progress_session(
+                directory=directory,
+                agent=agent,
+                session_id=session_id,
+                prompt='帮我生成一批地图导航测试数据。',
+            )
+
+            self.assertIsNone(_read_session_title(directory, session_id))
 
     def test_session_title_refines_first_message_title_after_run(self) -> None:
         with tempfile.TemporaryDirectory() as d:
@@ -850,12 +873,6 @@ class GuiServerTests(unittest.TestCase):
                 session_id=session_id,
                 prompt='帮我生成地图和餐饮服务的边界数据。',
             )
-            session_file = directory / session_id / 'session.json'
-            data = json.loads(session_file.read_text(encoding='utf-8'))
-            data['messages'] = [
-                {'role': 'user', 'content': '帮我生成地图和餐饮服务的边界数据。'}
-            ]
-            session_file.write_text(json.dumps(data), encoding='utf-8')
 
             with patch(
                 'backend.api.server._generate_session_title',
@@ -871,9 +888,11 @@ class GuiServerTests(unittest.TestCase):
                 )
 
             generate.assert_called_once()
-            updated = json.loads(session_file.read_text(encoding='utf-8'))
-            self.assertEqual(updated['title'], '地图餐饮边界数据')
-            self.assertEqual(updated['title_source'], 'llm')
+            metadata = load_agent_session(
+                session_id, directory=directory
+            ).session_metadata or {}
+            self.assertEqual(metadata['title'], '地图餐饮边界数据')
+            self.assertEqual(metadata['title_source'], 'llm')
 
     def test_session_title_preserves_existing_manual_title(self) -> None:
         with tempfile.TemporaryDirectory() as d:
@@ -881,21 +900,24 @@ class GuiServerTests(unittest.TestCase):
             _, state = _build_client(root)
             session_id = 'manual-preserved'
             directory = state.account_paths('alice')['sessions']
-            session_dir = directory / session_id
-            session_dir.mkdir(parents=True)
-            session_file = session_dir / 'session.json'
-            session_file.write_text(
-                json.dumps(
-                    {
-                        'session_id': session_id,
+            agent = state.agent_for('alice', session_id)
+            _save_in_progress_session(
+                directory=directory,
+                agent=agent,
+                session_id=session_id,
+                prompt='帮我分析数据。',
+            )
+            stored = load_agent_session(session_id, directory=directory)
+            save_agent_session(
+                replace(
+                    stored,
+                    session_metadata={
+                        **(stored.session_metadata or {}),
                         'title': '手动标题',
                         'title_source': 'manual',
-                        'messages': [
-                            {'role': 'user', 'content': '帮我分析数据。'},
-                        ],
-                    }
+                    },
                 ),
-                encoding='utf-8',
+                directory=directory,
             )
 
             with patch('backend.api.server._generate_session_title') as generate:
@@ -909,8 +931,10 @@ class GuiServerTests(unittest.TestCase):
                 )
 
             generate.assert_not_called()
-            updated = json.loads(session_file.read_text(encoding='utf-8'))
-            self.assertEqual(updated['title'], '手动标题')
+            metadata = load_agent_session(
+                session_id, directory=directory
+            ).session_metadata or {}
+            self.assertEqual(metadata['title'], '手动标题')
 
     def test_derive_initial_session_title_strips_session_context(self) -> None:
         title = _derive_initial_session_title(