Allow removing ID3v2 tags from FLAC and APE

CHANGELOG.md

@@ -27,6 +27,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - `lofty::read_from` will now wrap the `File` in a `BufReader`
 - **FLAC**: FLAC now has its own module at `lofty::flac`
 - **ID3v2**: `FrameValue` is now `#[non_exhaustive]`
+- `TagType::remove_from` now works for ID3v2 tags in APE and FLAC files
+  - This previously verified that the `FileType` supported the tag. It now has special exceptions for these formats to
+    allow stripping out these unsupported tags
 
 ### Fixed
 - **MP4**: Non-full `meta` atoms are now properly handled.

src/ape/write.rs

@@ -3,6 +3,8 @@ use crate::ape;
 use crate::error::{ErrorKind, LoftyError, Result};
 #[cfg(feature = "id3v1")]
 use crate::id3::v1;
+#[cfg(feature = "id3v2")]
+use crate::id3::v2;
 #[allow(unused_imports)]
 use crate::tag::{Tag, TagType};
 
@@ -17,6 +19,9 @@ pub(crate) fn write_to(data: &mut File, tag: &Tag) -> Result<()> {
 			items: ape::tag::tagitems_into_ape(tag.items()),
 		}
 		.write_to(data),
+		// This tag can *only* be removed in this format
+		#[cfg(feature = "id3v2")]
+		TagType::Id3v2 => v2::tag::Id3v2TagRef::empty().write_to(data),
 		#[cfg(feature = "id3v1")]
 		TagType::Id3v1 => Into::<v1::tag::Id3v1TagRef<'_>>::into(tag).write_to(data),
 		_ => Err(LoftyError::new(ErrorKind::UnsupportedTag)),

src/flac/mod.rs

@@ -17,7 +17,7 @@ use crate::id3::v2::tag::Id3v2Tag;
 #[cfg(feature = "vorbis_comments")]
 use crate::ogg::VorbisComments;
 use crate::properties::FileProperties;
-use crate::tag::TagType;
+use crate::tag::{Tag, TagType};
 
 use std::io::{Read, Seek};
 
@@ -44,15 +44,21 @@ pub struct FlacFile {
 }
 
 impl From<FlacFile> for TaggedFile {
+	#[allow(clippy::vec_init_then_push)]
 	fn from(input: FlacFile) -> Self {
+		let mut tags = Vec::<Option<Tag>>::with_capacity(2);
+
+		#[cfg(feature = "vorbis_comments")]
+		tags.push(input.vorbis_comments.map(Into::into));
+		#[cfg(feature = "id3v2")]
+		tags.push(input.id3v2_tag.map(Into::into));
+
 		Self {
 			ty: FileType::FLAC,
 			properties: input.properties,
-			#[cfg(feature = "vorbis_comments")]
-			tags: input
-				.vorbis_comments
-				.map_or_else(Vec::new, |t| vec![t.into()]),
-			#[cfg(not(feature = "vorbis_comments"))]
+			#[cfg(any(feature = "vorbis_comments", feature = "id3v2"))]
+			tags: tags.into_iter().flatten().collect(),
+			#[cfg(not(any(feature = "vorbis_comments", feature = "id3v2")))]
 			tags: Vec::new(),
 		}
 	}

src/id3/v2/tag.rs

@@ -428,6 +428,15 @@ pub(crate) struct Id3v2TagRef<'a, I: Iterator<Item = FrameRef<'a>> + 'a> {
 	pub(crate) frames: I,
 }
 
+impl<'a> Id3v2TagRef<'a, std::iter::Empty<FrameRef<'a>>> {
+	pub(crate) fn empty() -> Self {
+		Self {
+			flags: Id3v2TagFlags::default(),
+			frames: std::iter::empty(),
+		}
+	}
+}
+
 // Create an iterator of FrameRef from a Tag's items for Id3v2TagRef::new
 pub(crate) fn tag_frames(tag: &Tag) -> impl Iterator<Item = FrameRef<'_>> + '_ {
 	let items = tag

src/id3/v2/write/mod.rs

@@ -41,7 +41,7 @@ pub(crate) fn write_id3v2<'a, I: Iterator<Item = FrameRef<'a>> + 'a>(
 	let data = probe.into_inner();
 
 	match file_type {
-		Some(FileType::APE | FileType::MP3) => {},
+		Some(FileType::APE | FileType::MP3 | FileType::FLAC) => {},
 		// Formats such as WAV and AIFF store the ID3v2 tag in an 'ID3 ' chunk rather than at the beginning of the file
 		Some(FileType::WAV) => {
 			tag.flags.footer = false;
@@ -77,6 +77,7 @@ pub(super) fn create_tag<'a, I: Iterator<Item = FrameRef<'a>> + 'a>(
 	let frames = &mut tag.frames;
 	let mut peek = frames.peekable();
 
+	// We are stripping the tag
 	if peek.peek().is_none() {
 		return Ok(Vec::new());
 	}

src/ogg/write.rs

@@ -45,7 +45,7 @@ pub(in crate) fn write_to(file: &mut File, tag: &Tag, file_type: FileType) -> Re
 				pictures,
 			};
 
-			if let FileType::FLAC = file_type {
+			if file_type == FileType::FLAC {
 				return flac::write::write_to(file, &mut comments_ref);
 			}
 
@@ -58,6 +58,11 @@ pub(in crate) fn write_to(file: &mut File, tag: &Tag, file_type: FileType) -> Re
 
 			write(file, &mut comments_ref, format)
 		},
+		#[cfg(feature = "id3v2")]
+		TagType::Id3v2 if file_type == FileType::FLAC => {
+			// This tag can *only* be removed in this format
+			crate::id3::v2::tag::Id3v2TagRef::empty().write_to(file)
+		},
 		_ => Err(LoftyError::new(ErrorKind::UnsupportedTag)),
 	}
 }

src/tag/mod.rs

@@ -2,6 +2,7 @@ pub(crate) mod item;
 pub(crate) mod utils;
 
 use crate::error::{ErrorKind, LoftyError, Result};
+use crate::file::FileType;
 use crate::picture::{Picture, PictureType};
 use crate::probe::Probe;
 use crate::traits::{Accessor, TagExt};
@@ -448,7 +449,10 @@ impl TagType {
 			None => return Err(LoftyError::new(ErrorKind::UnknownFormat)),
 		};
 
-		if !file_type.supports_tag_type(*self) {
+		let special_exceptions =
+			(file_type == FileType::APE || file_type == FileType::FLAC) && *self == TagType::Id3v2;
+
+		if !special_exceptions && !file_type.supports_tag_type(*self) {
 			return Err(LoftyError::new(ErrorKind::UnsupportedTag));
 		}
 

tests/files/ape.rs

@@ -52,3 +52,8 @@ fn remove_ape() {
 fn remove_id3v1() {
 	crate::remove_tag!("tests/files/assets/minimal/full_test.ape", TagType::Id3v1);
 }
+
+#[test]
+fn remove_id3v2() {
+	crate::remove_tag!("tests/files/assets/minimal/full_test.ape", TagType::Id3v2);
+}

tests/files/ogg.rs

@@ -35,7 +35,7 @@ fn flac_write() {
 }
 
 #[test]
-fn flac_remove() {
+fn flac_remove_vorbis_comments() {
 	crate::remove_tag!(
 		"tests/files/assets/minimal/full_test.flac",
 		TagType::VorbisComments
@@ -135,3 +135,8 @@ fn flac_with_id3v2() {
 
 	assert!(flac_file.vorbis_comments().is_some());
 }
+
+#[test]
+fn flac_remove_id3v2() {
+	crate::remove_tag!("tests/files/assets/flac_with_id3v2.flac", TagType::Id3v2);
+}