`case_sensitive_file_extension_comparisons` hits on extension consisting of numbers

[cakebaker]

Summary

clippy::pedantic shows a warning when using ends_with() with a . followed by one to five numbers.

Lint Name

case_sensitive_file_extension_comparisons

Reproducer

I tried this code:

fn main() {
    "hello world".ends_with(".123");
}

I saw this happen:

$ cargo clippy -- -W clippy::pedantic
    Checking hello_world v0.1.0 (/home/dho/projects/hello_world)
warning: case-sensitive file extension comparison
 --> src/main.rs:2:5
  |
2 |     "hello world".ends_with(".123");
  |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |
  = help: consider using a case-insensitive comparison instead
  = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#case_sensitive_file_extension_comparisons
  = note: `-W clippy::case-sensitive-file-extension-comparisons` implied by `-W clippy::pedantic`
  = help: to override `-W clippy::pedantic` add `#[allow(clippy::case_sensitive_file_extension_comparisons)]`
help: use std::path::Path
  |
2 ~     std::path::Path::new("hello world")
3 +         .extension()
4 ~         .map_or(false, |ext| ext.eq_ignore_ascii_case("123"));
  |

warning: `hello_world` (bin "hello_world") generated 1 warning
    Finished dev [unoptimized + debuginfo] target(s) in 0.06s

I expected to see this happen:

No clippy warning

Version

rustc 1.76.0 (07dca489a 2024-02-04)
binary: rustc
commit-hash: 07dca489ac2d933c78d3c5158e3f43beefeb02ce
commit-date: 2024-02-04
host: x86_64-unknown-linux-gnu
release: 1.76.0
LLVM version: 17.0.6

Additional Labels

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[Ethiraric]

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