fix(parser): prevent crash on titles starting with numbers (#990)

Titles like "29 岁单身冒险家的日常" cause the regex to match the leading
number as episode, leaving title_raw as None. This cascades into storing
null aliases and crashing match_torrent with TypeError.

- Fall back to title_jp when title_en and title_zh are both None
- Return None from raw_parser when no title can be extracted
- Reject None/empty aliases in add_title_alias
- Filter null values from parsed title_aliases JSON
- Skip None title_raw in get_all_title_patterns

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: EstrellaXD

backend/src/module/database/bangumi.py

@@ -47,7 +47,9 @@ def _get_aliases_list(bangumi: Bangumi) -> list[str]:
         return []
     try:
         aliases = json.loads(bangumi.title_aliases)
-        return aliases if isinstance(aliases, list) else []
+        if not isinstance(aliases, list):
+            return []
+        return [a for a in aliases if a]
     except (json.JSONDecodeError, TypeError):
         return []
 
@@ -141,6 +143,10 @@ def add_title_alias(
             )
             return False
 
+        # Don't add None or empty aliases
+        if not new_title_raw:
+            return False
+
         # Don't add if it's the same as the main title_raw
         if bangumi.title_raw == new_title_raw:
             return False
@@ -165,7 +171,9 @@ def add_title_alias(
 
     def get_all_title_patterns(self, bangumi: Bangumi) -> list[str]:
         """Get all title patterns for matching (title_raw + all aliases)."""
-        patterns = [bangumi.title_raw]
+        patterns = []
+        if bangumi.title_raw:
+            patterns.append(bangumi.title_raw)
         patterns.extend(_get_aliases_list(bangumi))
         return patterns
 

backend/src/module/parser/title_parser.py

@@ -74,7 +74,7 @@ def raw_parser(raw: str) -> Bangumi | None:
                 "en": episode.title_en,
                 "jp": episode.title_jp,
             }
-            title_raw = episode.title_en if episode.title_en else episode.title_zh
+            title_raw = episode.title_en or episode.title_zh or episode.title_jp
             if titles[language]:
                 official_title = titles[language]
             elif titles["zh"]:
@@ -85,6 +85,9 @@ def raw_parser(raw: str) -> Bangumi | None:
                 official_title = titles["jp"]
             else:
                 official_title = title_raw
+            if not title_raw:
+                logger.warning("Cannot extract title_raw from '%s', skipping", raw)
+                return None
             _season = episode.season
             logger.debug("RAW:%s >> %s", raw, title_raw)
             return Bangumi(