redundant_closure_for_method_calls suggests wrong path if code inside module

Summary

.

Lint Name

redundant_closure_for_method_calls

Reproducer

I tried this code:

#![allow(clippy::stable_sort_primitive)]

use std::cell::Ref;
mod issue_5754 {}

// The closure parameter is not dereferenced anymore, so non-Copy types can be linted
mod issue_6001 {
    struct Test(String);

    impl Test {
        // Return an owned type so that we don't hit the fix for 5754
        fn name(&self) -> String {
            self.0.clone()
        }
    }

    pub fn test() {
        let mut args: Vec<Test> = vec![];

        // Forward
        args.sort_by_key(|a| a.name());
        args.sort_unstable_by_key(|a| a.name());
        // Reverse
        args.sort_by(|a, b| b.name().cmp(&a.name()));
        args.sort_unstable_by(|a, b| b.name().cmp(&a.name()));
    }
}

fn main() {
    issue_6001::test();
}

cargo clippy --fix -- -Aclippy::unnecessary_sort_by -Wclippy::pedantic

The following errors were reported:
error[E0433]: failed to resolve: use of undeclared crate or module `issue_6001`
  --> src/main.rs:21:26
   |
21 |         args.sort_by_key(issue_6001::Test::name);
   |                          ^^^^^^^^^^ use of undeclared crate or module `issue_6001`

error[E0433]: failed to resolve: use of undeclared crate or module `issue_6001`
  --> src/main.rs:22:35
   |
22 |         args.sort_unstable_by_key(issue_6001::Test::name);
   |                                   ^^^^^^^^^^ use of undeclared crate or module `issue_6001`

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0433`.
Original diagnostics will follow.

warning: unused import: `std::cell::Ref`
 --> src/main.rs:3:5
  |
3 | use std::cell::Ref;
  |     ^^^^^^^^^^^^^^
  |
  = note: `#[warn(unused_imports)]` on by default

warning: redundant closure
  --> src/main.rs:21:26
   |
21 |         args.sort_by_key(|a| a.name());
   |                          ^^^^^^^^^^^^ help: replace the closure with the method itself: `issue_6001::Test::name`
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_closure_for_method_calls
   = note: `-W clippy::redundant-closure-for-method-calls` implied by `-W clippy::pedantic`

warning: redundant closure
  --> src/main.rs:22:35
   |
22 |         args.sort_unstable_by_key(|a| a.name());
   |                                   ^^^^^^^^^^^^ help: replace the closure with the method itself: `issue_6001::Test::name`
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_closure_for_method_calls

Version

rustc 1.67.0-nightly (b3bc6bf31 2022-11-24)
binary: rustc
commit-hash: b3bc6bf31265ac10946a0832092dbcedf9b26805
commit-date: 2022-11-24
host: x86_64-unknown-linux-gnu
release: 1.67.0-nightly
LLVM version: 15.0.4

Additional Labels

No response

Start with the redundant_closure_for_method_calls lint and reproduce the diagnostic using the Rust code and cargo clippy command in the issue. Check how method paths are formed for calls inside issue_6001, then ensure the suggested replacement resolves from that module without E0433. Re-run the reproducer and verify the lint's replacement compiles.