ID3v2: Handle TXXX ItemKey conversions correctly

CHANGELOG.md

@@ -15,6 +15,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 - **MusePack**: Fix potential panic when the beginning silence makes up the entire sample count ([PR](https://github.com/Serial-ATA/lofty-rs/pull/449))
 - **Timestamp**: Support timestamps without separators (ex. "20240906" vs "2024-09-06") ([issue](https://github.com/Serial-ATA/lofty-rs/issues/452)) ([PR](https://github.com/Serial-ATA/lofty-rs/issues/453))
+- **ID3v2**: `ItemKey::Director` will now be written correctly as a TXXX frame ([PR](https://github.com/Serial-ATA/lofty-rs/issues/454))
 
 ## [0.21.1] - 2024-08-28
 

lofty/src/id3/v2/tag.rs

@@ -1379,7 +1379,6 @@ impl MergeTag for SplitTagRemainder {
 			&ItemKey::Composer,
 			&ItemKey::Conductor,
 			&ItemKey::Writer,
-			&ItemKey::Director,
 			&ItemKey::Lyricist,
 			&ItemKey::MusicianCredits,
 			&ItemKey::InternetRadioStationName,
@@ -1403,8 +1402,11 @@ impl MergeTag for SplitTagRemainder {
 		}
 
 		// Multi-valued TXXX key-to-frame mappings
-		#[allow(clippy::single_element_loop)]
-		for item_key in [&ItemKey::TrackArtists] {
+		for item_key in [
+			&ItemKey::TrackArtists,
+			&ItemKey::Director,
+			&ItemKey::CatalogNumber,
+		] {
 			let frame_id = item_key
 				.map_key(TagType::Id3v2, false)
 				.expect("valid frame id");
@@ -1521,6 +1523,7 @@ impl MergeTag for SplitTagRemainder {
 			));
 		}
 
+		// iTunes advisory rating
 		'rate: {
 			if let Some(advisory_rating) = tag.take_strings(&ItemKey::ParentalAdvisory).next() {
 				let Ok(rating) = advisory_rating.parse::<u8>() else {