x.py fmt <file> sometimes formats other files

[jyn514]

The per-file thing does not entirely work... when I ask x.py to format library/core/src/intrinsics.rs, it also formats library/core/src/panicking.rs.

Originally posted by @RalfJung in #102837 (comment)

[jyn514]

@RalfJung can you post the commit you were on and the diff x.py created?

[RalfJung]

I wasn't on a commit as the committed files are all formatted already. So I introduced changes in both files and then triggered RA formatting, and it ended up undoing my changes in both files.

[RalfJung]

But strangely, I cannot reproduce outside of RA... when I invoke ./x.py fmt filename myself, it behaves as expected; when I ask it to do formatting from RA, it formats other files, too.

[RalfJung]

Oh, is it possible that RA expects the formatting to happen via stdin/stdout? I was wondering how things would work for files with mod statements where calling rustfmt with the filename causes it to recurse.

[RalfJung]

Yes indeed, formatting in RA happens via stdin/stdout. So the filename argument is not the problem.