Re: [PATCH] unpack-trees: do not fail reset because of unmerged skipped entry

From: Junio C Hamano <gitster@pobox.com>
Date: Jun 15, 2018, 19:58 UTC
Message-ID: <xmqqh8m3zurz.fsf@gitster-ct.c.googlers.com>
In-Reply-To: <20180615044251.10597-1-max@max630.net>

Max Kirillov <max@max630.net> writes:

Show 11 quoted lines

> After modify/delete merge conflict happens in a file skipped by sparse
> checkout, "git reset --merge", which implements the "--abort" actions, and
> "git reset --hard" fail with message "Entry * not uptodate. Cannot update
> sparse checkout." The reason is that the entry is verified in
> apply_sparse_checkout() for being up-to-date even when it has a conflict.
> Checking conflicted entry for being up-to-date is not performed in other
> cases. One obvious reason to not check it is that it is already modified
> by inserting conflict marks.
>
> Fix by not checking conflicted entries before performing reset.
> Also, add test case which verifies the issue is fixed.

I do not know offhand if "reset --merge" should force succeeding in such a case, but I agree that it is criminal to stop "reset --hard" with "not uptodate", as the whole point of "hard reset" is to get rid of the 'not up-to-date' modification.

I guess not may people make serious use of sparsely checked-out working tree and that is why such a failure is reported this late after the feature was introduced?

> +test_expect_success 'reset --hard works after the conflict' '
> +	git reset --hard
> +'

Do we want to verify the state after the 'hard' reset succeeds as well? Things like

 - all paths in the HEAD and all paths in the index are identical;

 - paths that do exist in the working tree are all identical to HEAD
   version; and

 - paths that do not exist in the working tree are missing due to
   the sparse checkout setting (iow, it is a bug if a path that is
   outside the "sparse" setting is missing from the working tree).

Show 7 quoted lines

> +test_expect_success 'setup: conflict back' '
> +	! git merge theirs
> +'
> +
> +test_expect_success 'Merge abort works after the conflict' '
> +	git merge --abort
> +'

Likewise here.

Show 14 quoted lines

> +test_done
> diff --git a/unpack-trees.c b/unpack-trees.c
> index e73745051e..65ae0721a6 100644
> --- a/unpack-trees.c
> +++ b/unpack-trees.c
> @@ -468,7 +468,7 @@ static int apply_sparse_checkout(struct index_state *istate,
>  		 * also stat info may have lost after merged_entry() so calling
>  		 * verify_uptodate() again may fail
>  		 */
> -		if (!(ce->ce_flags & CE_UPDATE) && verify_uptodate_sparse(ce, o))
> +		if (!(ce->ce_flags & CE_UPDATE) && !(ce->ce_flags & CE_CONFLICTED) && verify_uptodate_sparse(ce, o))
>  			return -1;
>  		ce->ce_flags |= CE_WT_REMOVE;
>  		ce->ce_flags &= ~CE_UPDATE;

Thanks.