Re: Issue when changing staged files in a pre-commit hook

Duy Nguyen [off-list ref] writes:

I think it's the intended behavior.

Yeah, pre-commit was designed for inspecting and rejecting, not for
tweaking and munging.  Perhaps "git commit" can be tightened to make
sure that pre-commit that returns successfully did not muck with the
working tree and the index?

On Wed, Jan 20, 2016 at 1:44 AM, Junio C Hamano [off-list ref] wrote:

Duy Nguyen [off-list ref] writes:

quoted

I think it's the intended behavior.

Yeah, pre-commit was designed for inspecting and rejecting, not for
tweaking and munging.  Perhaps "git commit" can be tightened to make
sure that pre-commit that returns successfully did not muck with the
working tree and the index?

That was my impression from the docs, but then I saw this comment,

/*
* Re-read the index as pre-commit hook could have updated it,
* and write it out as a tree.  We must do this before we invoke
* the editor and after we invoke run_status above.
*/

which comes from 2888605 (builtin-commit: fix partial-commit support -
2007-11-18) that admits "the hook can modify it (the index)". And I
was about to update the docs, but the other way around, about updating
index and side effects.
-- 
Duy