pre-push hook should only look at staged changes

[jyn514]

if i have modified the repository locally, but not committed those changes, and i run git push, i expect it to lint on the changes that are actually going to be pushed, not the ones i have laying around.

instead, src/etc/pre-push lints on the working directory.

it would be nice if it checked if there are unstaged changes, and if so copied the working directory to a tempdir to run the checks there. here is a hacky bash script that does it for checks that work file-at-a-time; i don't think tidy ever looks at multiple files at once or tries to build code, but if it does it would need more work.

Meta

HEAD is f989d2f

@rustbot label +A-bootstrap +A-contributor-roadblock +E-medium

[jieyouxu]

Some additional context: see also #147084 (comment)

I think that doing anything with untracked files might be a bit dangerous. I personally wouldn't want these scripts ever touching anything untracked by git.

I'll add that please do not use the git stash mechanism for this (don't interfere with user's git stash pls, that would be very annoying).

See also the discussion thread: #general > Pre-push hook doing git stash