Regression: `undocumented_unsafe_blocks` false positive on a multi-line attribute between // SAFETY and `unsafe`

[purplesyringa]

Summary

Seems to be a recent regression. I'm not sure what the release cycle for clippy is, but it has appreared in rustup's nightly within the last week. Maybe due to #15678?

Lint Name

undocumented_unsafe_blocks

Reproducer

I tried this code:

#![warn(clippy::undocumented_unsafe_blocks)]

unsafe fn f() {}

fn main() {
    // SAFETY: trust me
    #[allow(
        unused // can be any lint
    )]
    unsafe {
        f();
    }
}

I saw this happen:

warning: unsafe block missing a safety comment
  --> src/main.rs:10:5
   |
10 |     unsafe {
   |     ^^^^^^^^
   |
   = help: consider adding a safety comment on the preceding line
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#undocumented_unsafe_blocks
note: the lint level is defined here
  --> src/main.rs:1:9
   |
 1 | #![warn(clippy::undocumented_unsafe_blocks)]
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

I expected to see this happen:

no warning

Version

clippy 0.1.92 (f04e3dfc87 2025-10-19)

Additional Labels

No response

[profetia]

This is caused by changes in checking attribute, in this function:

rust-clippy/clippy_lints/src/undocumented_unsafe_blocks.rs

Line 838 in 0c592df

fn is_attribute(text: &str) -> bool {