cfg[feature] is removed when feature name is too long

[Longarithm]

Input

pub(crate) fn f(
    #[cfg(feature = "this_feature_name_is_long_enough_not_to_fit_inside_the_standard_limit")] x: u64,
) -> () {}

Output

pub(crate) fn f(x: u64) -> () {}

Please note that the behaviour is the same where argument is actually used. I removed its usage just for simplicity.

Meta

• rustfmt version: rustfmt 1.4.20-stable (48f6c32 2020-08-09) or rustfmt 1.4.36-nightly (7de6968 2021-02-07)
• From where did you install rustfmt?: rustup
• How do you run rustfmt: cargo fmt or cargo +nightly fmt

[Longarithm]

Cc @matklad

[calebcartwright]

Thanks for reaching out! This is a duplicate (though can't find the previous issue at this moment) and has already been fixed in source. Will be sure to add a test case for your input though, and pull it into the upcoming 1.4.38 release

[karyon]

duplicate of #4579, fix shipped in 1.4.38