ref_transaction_verify(): new function to check a reference's value
authorMichael Haggerty <mhagger@alum.mit.edu>
Tue, 17 Feb 2015 17:00:21 +0000 (18:00 +0100)
committerJunio C Hamano <gitster@pobox.com>
Tue, 17 Feb 2015 19:24:59 +0000 (11:24 -0800)
commit16180334015ab44b0310b9d896e554a66c36a1a4
tree367a45d10a3186a88121c42d28551650d814be94
parent60294596ba6bf2f63506ffad60b9a94fc04612a1
ref_transaction_verify(): new function to check a reference's value

If NULL is passed to ref_transaction_update()'s new_sha1 parameter,
then just verify old_sha1 (under lock) without trying to change the
new value of the reference.

Use this functionality to add a new function ref_transaction_verify(),
which checks the current value of the reference under lock but doesn't
change it.

Use ref_transaction_verify() in the implementation of "git update-ref
--stdin"'s "verify" command to avoid the awkward need to "update" the
reference to its existing value.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
builtin/update-ref.c
refs.c
refs.h