The slash (`/`) characters in tags are not correctly parsed

[tranxuanthang]

Looks like slash characters in tags are not parsed correctly by rust-id3 and are converted to null terminator character.

Some examples are:

• (artist name) Alan Walker, Au/Ra, Tomine Harket => "Alan Walker, Au\0Ra, Tomine Harket"
• (artist name) Derek Duke/Russell Brower => "Derek Duke\0Russell Brower"
• (album & track name) Misty Mountains (In Dwarvish/Khuzdul) => "Misty Mountains (In Dwarvish\0Khuzdul)"

EDIT: Update example file. I'm not quite sure yet but it seems that the issue only happens in ID3 v2.3 version.

let mut tag = id3::Tag::new();
tag.add_frame(id3::Frame::text("TPE1", "Derek Duke/Russell Brower"));
tag.write_to_path("test.id3", id3::Version::Id3v23).unwrap();

let tag = id3::Tag::read_from_path("test.id3").unwrap();
println!("{:?}", tag.artist()); // Some("Derek Duke\0Russell Brower")

test.zip

[tranxuanthang]

After seeing these:

• https://github.com/polyfloyd/rust-id3/issues/82
• https://github.com/martpie/rust-id3/commit/ce18ca8cb87410ac5901dfbc1bc78b616306b8d2

I understand the issue better now. But still I think assuming the slash / character as separator for multiple entries for ID3 v2.2 or v2.3 might end up messing with a few artist names. One of these cases is my first example, calling tag.artists() will get you Some(["Alan Walker, Au", "Ra, Tomine Harket"]).

At least, I think the null/slash substitute definitely should not apply for all text fields, for example album name and track name. And tag.artist() should return the expected result, without null terminator character.

[polyfloyd]

ID3 has support for split values in text frames. In v2.2 and v2.3 the separator is a slash while in v2.4 it is a null byte.

I intended the library to have a uniform ID3v2.4 interface, so everything that it reads is normalized to use null bytes. But I must admit that this leaves much to desire...

Splitting happens at a very low level, just after decoding at src/stream/frame/content.rs:449

It might be worth considering making the split functions of TagLike version aware so at least the underlying content remains untouched unless desired