while_let_loop false positive

fn main() {
    let mut lines = "foo".lines().peekable();
    // Gather remaining non-empty lines into a comment field.
    let mut comment = String::new();
    loop {
        if let Some(line) = lines.peek() {
            if line.is_empty() {
                break;
            } else {
                comment += line;
            }
        } else {
            break;
        }
        // Consume
        lines.next();
    }
}

warning: this loop could be written as a `while let` loop
  --> src/main.rs:5:5
   |
5  | /     loop {
6  | |         if let Some(line) = lines.peek() {
7  | |             if line.is_empty() {
8  | |                 break;
...  |
16 | |         lines.next();
17 | |     }
   | |_____^
   |
   = note: #[warn(while_let_loop)] on by default
help: try
   |     while let Some(line) = lines.peek() { .. }

This can't be trivially transformed into while let, since lines.next() is called unconditionally outside of the if let statement.

Reproduce the warning with the Rust example in the issue and inspect the implementation of the while_let_loop lint. Trace why the unconditional lines.next() is treated as compatible with the suggested rewrite. Done means this example no longer receives an invalid while let suggestion, with regression coverage for the reported pattern.