fix: prevent mimetypes hang on Windows by skipping registry init (#2059)

Co-authored-by: E <e@local.com>
Co-authored-by: zhulinsen <42829555+ZhuLinsen@users.noreply.github.com>

api/app.py

@@ -19,6 +19,17 @@ import asyncio
 import json
 import logging
 import mimetypes
+
+import sys
+
+if sys.platform == "win32" and not mimetypes.inited:
+    _orig_read_windows_registry = getattr(mimetypes.MimeTypes, 'read_windows_registry', None)
+    if _orig_read_windows_registry is not None:
+        mimetypes.MimeTypes.read_windows_registry = lambda self, strict=True: None
+        try: mimetypes.init()
+        finally: mimetypes.MimeTypes.read_windows_registry = _orig_read_windows_registry
+    else:
+        mimetypes.init()
 import os
 import re
 from contextlib import asynccontextmanager, suppress

docs/CHANGELOG.md

@@ -18,6 +18,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/).
 - [新功能] Tushare 数据源支持通过 `TUSHARE_HTTP_URL` 环境变量自定义接入地址，便于网络无法直达 `api.tushare.pro` 时切换自建网关或第三方兼容镜像；留空保持官方默认地址不变（fixes #1985）
 - [文档] `.env.example` 与 `.github/workflows/00-daily-analysis.yml` 同步映射 `TUSHARE_HTTP_URL`，避免出现"配置项有但 workflow 漏映射"的半修状态
 - [修复] #2051 PR Review 的特权 `pull_request_target` 流程不再检出 fork PR head：敏感文件、标签、报告与 AI 审查统一通过 GitHub API 将 PR 元数据和 diff 作为数据读取，只执行主分支可信脚本；Python 语法、Flake8、确定性检查和离线测试继续由无 secrets 的 `pull_request` CI / `backend-gate` 执行，兼容 `actions/checkout` 新增的 fork checkout 安全保护。
+- [修复] 修复 Windows 上 mimetypes 冷启动时读取注册表导致的进程卡死
 
 ## [3.27.0] - 2026-07-19
 

tests/test_mimetypes_windows_init.py

@@ -0,0 +1,89 @@
+# -*- coding: utf-8 -*-
+"""Tests for mimetypes cold-start behaviour on Windows."""
+
+import importlib
+import mimetypes
+import sys
+import unittest
+from unittest.mock import patch
+
+
+class MimetypesWindowsInitTestCase(unittest.TestCase):
+    """Cold-start: Windows skips registry; non-Windows keeps full MIME db."""
+
+    def setUp(self):
+        self._types_map_backup = dict(mimetypes.types_map)
+
+    def tearDown(self):
+        mimetypes.types_map.clear()
+        mimetypes.types_map.update(self._types_map_backup)
+
+    @staticmethod
+    def _simulate_cold_start():
+        mimetypes.inited = False
+        mimetypes._db = None
+
+    def test_windows_cold_import_skips_registry(self):
+        """Windows cold-start must not call read_windows_registry."""
+        import api.app
+
+        self._simulate_cold_start()
+        with patch("sys.platform", "win32"), \
+             patch.object(mimetypes.MimeTypes, "read_windows_registry") as mock_registry:
+            importlib.reload(api.app)
+
+        mock_registry.assert_not_called()
+
+    def test_non_windows_retains_full_mime_guessing(self):
+        """Non-Windows must NOT replace the system MIME database."""
+        import api.app
+
+        self._simulate_cold_start()
+        with patch("sys.platform", "linux"):
+            importlib.reload(api.app)
+
+        self.assertEqual(
+            mimetypes.guess_type("index.html")[0],
+            "text/html",
+            "HTML must still be detected on non-Windows",
+        )
+        self.assertEqual(
+            mimetypes.guess_type("test.pdf")[0],
+            "application/pdf",
+            "PDF must still be detected on non-Windows",
+        )
+
+    def test_types_map_consistent_with_db(self):
+        """types_map and _db.types_map[True] must be the same object."""
+        import api.app
+
+        self._simulate_cold_start()
+        with patch("sys.platform", "win32"):
+            importlib.reload(api.app)
+
+        self.assertIs(
+            mimetypes.types_map,
+            mimetypes._db.types_map[True],
+            "types_map must reference _db internals (no split-brain)",
+        )
+
+    def test_frontend_mime_types_registered_after_init(self):
+        """_register_frontend_asset_mime_types must work after cold-start init."""
+        import api.app
+
+        self._simulate_cold_start()
+        with patch("sys.platform", "win32"):
+            importlib.reload(api.app)
+
+        api.app._register_frontend_asset_mime_types()
+
+        self.assertEqual(
+            mimetypes.guess_type("app.js")[0], "text/javascript"
+        )
+        self.assertEqual(
+            mimetypes.guess_type("style.css")[0], "text/css"
+        )
+
+
+if __name__ == "__main__":
+    unittest.main()