fix: correct traditional Chinese subtitle rename detection

Fixes #5703

app/modules/filemanager/transhandler.py

@@ -660,10 +660,11 @@ class TransHandler:
         new_file_type = ""
 
         # 识别字幕语言
-        if re.search(_zhcn_sub_re, sub_item.name, re.I):
+        # 先识别繁中，避免“繁体中文/繁中字”等名称被后面的“中文/中字”简中兜底规则误判。
-            new_file_type = ".chi.zh-cn"
+        if re.search(_zhtw_sub_re, sub_item.name, re.I):
-        elif re.search(_zhtw_sub_re, sub_item.name, re.I):
             new_file_type = ".zh-tw"
+        elif re.search(_zhcn_sub_re, sub_item.name, re.I):
+            new_file_type = ".chi.zh-cn"
         elif re.search(_ja_sub_re, sub_item.name, re.I):
             new_file_type = ".ja"
         elif re.search(_eng_sub_re, sub_item.name, re.I):

tests/test_subtitle_rename.py

@@ -0,0 +1,50 @@
+from pathlib import Path
+from unittest import TestCase
+
+from app.core.config import settings
+from app.modules.filemanager.transhandler import TransHandler
+from app.schemas.file import FileItem
+
+
+class SubtitleRenameTest(TestCase):
+    def setUp(self) -> None:
+        self._default_sub = settings.DEFAULT_SUB
+
+    def tearDown(self) -> None:
+        settings.DEFAULT_SUB = self._default_sub
+
+    @staticmethod
+    def _rename_subtitle(sub_name: str, default_sub: str) -> Path:
+        """
+        直接调用字幕重命名逻辑，覆盖语言标签识别与默认字幕标记。
+        """
+        settings.DEFAULT_SUB = default_sub
+        sub_item = FileItem(
+            storage="local",
+            type="file",
+            path=f"/source/{sub_name}.srt",
+            name=sub_name,
+            extension="srt",
+        )
+        target_file = Path("/target/24 Hours.2001.S02E01.[tmdbid=14064].srt")
+        return TransHandler._TransHandler__rename_subtitles(sub_item, target_file)
+
+    def test_traditional_chinese_subtitle_is_not_misclassified_as_simplified(self):
+        """
+        issue #5703: “繁体中文” 不应命中简中兜底规则，也不应被打上默认简中标签。
+        """
+        renamed = self._rename_subtitle("24.Hours.S02E01.繁体中文", default_sub="zh-cn")
+        self.assertEqual(
+            renamed.name,
+            "24 Hours.2001.S02E01.[tmdbid=14064].zh-tw.srt",
+        )
+
+    def test_traditional_chinese_subtitle_can_be_marked_as_default(self):
+        """
+        当默认字幕设置为繁中时，仍应保留正确的繁中语言后缀并追加 default 标记。
+        """
+        renamed = self._rename_subtitle("24.Hours.S02E01.繁体中文", default_sub="zh-tw")
+        self.assertEqual(
+            renamed.name,
+            "24 Hours.2001.S02E01.[tmdbid=14064].default.zh-tw.srt",
+        )