Fix prepare_commit.sh

[strk]

This was broken with 135c4cb
this commit fixes it

[strk]

It was actually broken by b84393e in that a grep not matching anything results in the whole pipeline evaluating to false and set -e at the beginning of the file makes that a failure that interrupts the script and prevents commit

[strk]

And b84393e comes from #54893

[strk]

@troopa81 a commit in this PR also updates instruction as to how to properly set the pre-commit hook for it to work in any worktree, in case that's what prevented you from properly testing it (it surely prevented me)

[troopa81]

@troopa81 a commit in this PR also updates instruction as to how to properly set the pre-commit hook for it to work in any worktree, in case that's what prevented you from properly testing it (it surely prevented me)

My hook is correctly set at the root of my repository and I'm not sure the modification on CONTRIBUTING.md are worthy (it brings more complexity).

I didn't tested your modification. Same here, I didn't tested but it looks good to me.

[strk]

@troopa81 "correctly set" how ? Making pre-commit a symlink as suggested in CONTRIBUTING.md before this change would not be "correctly set" as it would always run the prepare-commit.sh script from the branch checked out in the "toplevel" git repository, and never in other worktrees, where you might be experimenting with changes to that script (as I was doing).

[troopa81]

@strk you're right, thanks for the tips