unpack-trees: do not fail reset because of unmerged skipped entry

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."

As explained in [1], the up-to-date checker mistakenly treats conflicted
entry which does not exist in HEAD as still skipped by sparse checkout.

Use the fix suggested in [1]. Also, add test case which verifies the
issue is fixed.

[1] https://public-inbox.org/git/20180616051444.GA29754@duynguyen.home/

Signed-off-by: Duy Nguyen <pclouds@gmail.com>
Signed-off-by: Max Kirillov <max@max630.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

0 files changed, 0 insertions, 0 deletions