Are changes in album_info actually applied in mbsync?

[amogus07]

I'm confused about this snippet in the mbsync plugin:

            with lib.transaction():
                AlbumMatch(
                    Distance(), album_info, dict(item_info_pairs)
                ).apply_metadata()
                changed = False
                # Find any changed item to apply changes to album.
                any_changed_item = items[0]
                for item in items:
                    item_changed = ui.show_model_changes(item)
                    changed |= item_changed
                    if item_changed:
                        any_changed_item = item
                        apply_item_changes(lib, item, move, pretend, write)

                if not changed:
                    # No change to any item.
                    continue

                if not pretend:
                    # Update album structure to reflect an item in it.
                    for key in library.Album.item_keys:
                        album[key] = any_changed_item[key]
                    album.store()

                    # Move album art (and any inconsistent items).
                    if move and lib.directory in util.ancestry(items[0].path):
                        self._log.debug("moving album {}", album)
                        album.move()

I don't see fields like label that are only stored in album_info being applied anywhere. Is this intentional? The reason I'm asking is because the plugin I'm working on, beets-vocadb, where the corresponding code currently looks like this:

            with lib.transaction():
                AlbumMatch(
                    distance=Distance(), info=album_info, mapping=mapping
                ).apply_metadata()
                # Copy flexible attributes from album_info to album
                for flex_key in (
                    "cover_art_url",
                    "data_source",
                    "label",
                    *self._flexible_attributes.album.values(),
                ):
                    if flex_key in album_info:
                        album[flex_key] = album_info[flex_key]
                _ = show_model_changes(new=album)
                changed: bool = False
                any_changed_item: library.Item | None = items.get()
                for item in items:
                    item_changed: bool = show_model_changes(new=item)
                    changed |= item_changed
                    if item_changed:
                        any_changed_item = item
                        apply_item_changes(lib, item, move, pretend, write)
                if pretend or not changed or not any_changed_item:
                    continue
                key: str
                for key in album.item_keys - {
                    "original_day",
                    "original_month",
                    "original_year",
                    "genres",
                    "language",
                    "script",
                }:
                    album[key] = any_changed_item[key]
                album.store()  # pyright: ignore[reportUnknownMemberType]
                if move and lib.directory in ancestry(
                    path=any_changed_item.path
                ):
                    self._log.debug("moving album {}", album)
                    album.move()  # pyright: ignore[reportUnknownMemberType]

Is it correct like this?

[amogus07]

Just realized there's a logic bug in the snippet, should be fixed here:

            with lib.transaction():
                AlbumMatch(
                    distance=Distance(), info=album_info, mapping=mapping
                ).apply_metadata()
                # Copy flexible attributes from album_info to album
                for flex_key in (
                    "cover_art_url",
                    "data_source",
                    "label",
                    *(
                        self._flexible_attributes(name)
                        for name in AlbumFlexibleAttributes
                    ),
                ):
                    if album_info.get(flex_key):
                        album[flex_key] = album_info[flex_key]
                _ = show_model_changes(new=album)
                changed: bool = False
                any_changed_item: library.Item | None = items.get()
                for item in items:
                    item_changed: bool = show_model_changes(new=item)
                    changed |= item_changed
                    if item_changed:
                        any_changed_item = item
                        apply_item_changes(lib, item, move, pretend, write)
                if pretend:
                    continue
                if any_changed_item and changed:
                    key: str
                    for key in album.item_keys - {
                        "original_day",
                        "original_month",
                        "original_year",
                        "genres",
                        "language",
                        "script",
                    }:
                        album[key] = any_changed_item[key]
                album.store()  # pyright: ignore[reportUnknownMemberType]
                if (
                    move
                    and any_changed_item
                    and lib.directory in ancestry(path=any_changed_item.path)
                ):
                    self._log.debug("moving album {}", album)
                    album.move()  # pyright: ignore[reportUnknownMemberType]