Document ordering of the genre split separator

Author: snejus

beets/autotag/hooks.py

@@ -87,7 +87,7 @@ def __init__(
             )
             if not genres:
                 try:
-                    sep = next(s for s in [", ", "; ", " / "] if s in genre)
+                    sep = next(s for s in ["; ", ", ", " / "] if s in genre)
                 except StopIteration:
                     genres = [genre]
                 else:

beets/library/migrations.py

@@ -37,7 +37,7 @@ def separators(self) -> list[str]:
         with suppress(ConfigError):
             separators.append(beets.config["lastgenre"]["separator"].as_str())
 
-        separators.extend([", ", "; ", " / "])
+        separators.extend(["; ", ", ", " / "])
         return unique_list(filter(None, separators))
 
     @contextmanager

docs/changelog.rst

@@ -26,6 +26,14 @@ New features
   splitting genre strings and writing the changes to both the database and media
   files. No manual action or ``mbsync`` is required.
 
+  The ``genre`` field is split by the first separator found in the string, in
+  the following order of precedence:
+
+  1. :doc:`plugins/lastgenre` ``separator`` configuration
+  2. Semicolon followed by a space
+  3. Comma followed by a space
+  4. Slash wrapped by spaces
+
 Bug fixes
 ~~~~~~~~~