Weird comment indent with let+match

[eefriedman]

impl ISizeAndMarginsComputer for AbsoluteNonReplaced {
    fn solve_inline_size_constraints(&self,
                                     block: &mut BlockFlow,
                                     input: &ISizeConstraintInput)
                                     -> ISizeConstraintSolution {
        let (inline_start, inline_size, margin_inline_start, margin_inline_end) =
            match (inline_start, inline_end, computed_inline_size) {
                (MaybeAuto::Auto, MaybeAuto::Auto, MaybeAuto::Auto) => {
                    let margin_start = inline_start_margin.specified_or_zero();
                    let margin_end = inline_end_margin.specified_or_zero();
                    // Now it is the same situation as inline-start Specified and inline-end
                    // and inline-size Auto.
                    //
                    // Set inline-end to zero to calculate inline-size.
                    let inline_size =
                        block.get_shrink_to_fit_inline_size(available_inline_size -
                                                            (margin_start + margin_end));
                    (Au(0), inline_size, margin_start, margin_end)
                }
            };
    }
}

rustfmt output:

                 (MaybeAuto::Auto, MaybeAuto::Auto, MaybeAuto::Auto) => {⏎
                     let margin_start = inline_start_margin.specified_or_zero();⏎
                     let margin_end = inline_end_margin.specified_or_zero();⏎
+        // Now it is the same situation as inline-start Specified and inline-end⏎
+        // and inline-size Auto.⏎
+        //⏎
+        // Set inline-end to zero to calculate inline-size.⏎
-                    // Now it is the same situation as inline-start Specified and inline-end⏎
-                    // and inline-size Auto.⏎
-                    //⏎
-                    // Set inline-end to zero to calculate inline-size.⏎
                     let inline_size =⏎
                         block.get_shrink_to_fit_inline_size(available_inline_size -⏎
                                                             (margin_start + margin_end));⏎

[marcusklaas]

How is possible that let items are indent correctly, but no comment?

Extreme confuse.

[marcusklaas]

If one replaces

let (inline_start, inline_size, margin_inline_start, margin_inline_end) =

by

let (inline_start, inline_size, margin_inline_start) =

, the snippet is formatted as expected.

This leads me to believe that the tuple width heuristic is at work here...

[marcusklaas]

So the weird is only a symptom, not the bug itself per se! We try to format the statement, fail and hence the assignment is caught in a missing span. There the comments are seen in the outer context, with a more shallow indentation.