PICARD-2307: Fix ValueError for Vorbis when deleting invalid tags

picard/formats/vorbis.py

@@ -321,7 +321,7 @@ class VCommentFile(File):
         """Remove the tags from the file that were deleted in the UI"""
         for tag in metadata.deleted_tags:
             real_name = self._get_tag_name(tag)
-            if real_name and real_name in tags:
+            if is_valid_key(real_name) and real_name in tags:
                 if real_name in ('performer', 'comment'):
                     parts = tag.split(':', 1)
                     if len(parts) == 2:

test/formats/test_vorbis.py

@@ -184,6 +184,15 @@ class CommonVorbisTests:
             self.assertNotIn('tracktotal', loaded_metadata)
             self.assertNotIn('totaltracks', loaded_metadata)
 
+        @skipUnlessTestfile
+        def test_delete_invalid_tagname(self):
+            # Deleting tags that are not valid Vorbis tag names must not trigger
+            # an error
+            for invalid_tag in INVALID_KEYS:
+                metadata = Metadata()
+                del metadata[invalid_tag]
+                save_metadata(self.filename, metadata)
+
 
 class FLACTest(CommonVorbisTests.VorbisTestCase):
     testfile = 'test.flac'