On Wed, Jan 20, 2016 at 6:41 AM, Junio C Hamano <gitster@xxxxxxxxx> wrote: > Duy Nguyen <pclouds@xxxxxxxxx> writes: > >> On Wed, Jan 20, 2016 at 1:44 AM, Junio C Hamano <gitster@xxxxxxxxx> wrote: >>> Duy Nguyen <pclouds@xxxxxxxxx> 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? >> >> 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. > > I do not think the comment is wrong per-se, but the code we have, > either back then or even today, is insufficient to allow pre-commit > hook that mucks with the fake index that is shown to it. > > Re-reading the in-core index at that point may help creating a > commit whose tree matches what the hook did, but the extra change > made by the hook is not ported forward in the real index that the > user will use after a partial commit (and there is no easy way to do > so cleanly--the change the hook makes may even overlap the change in > the real index that are added but left uncommitted, and you would > end up needing to run a threeway merge). > > The only sensible thing we can do at that point in the code after > re-reading the index is to make sure that hasn't been changed by the > pre-commit hook and complain loudly to die if we find it modified, I > think. OK. Two more points - do we catch index changes for partial commit case only? Because when $GIT_DIR/index is used, we do not have this problem. - is Niek's use case still valid? If so, what do we do to support it (at least in partial commit case)? -- Duy -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html