Re: Bug in "git rev-parse --verify"

From: Junio C Hamano <gitster@pobox.com>
Date: Mar 28, 2013, 16:52 UTC
Message-ID: <7vli97v558.fsf@alter.siamese.dyndns.org>
In-Reply-To: <20130328153808.GB3337@sigill.intra.peff.net>

Jeff King <peff@peff.net> writes:

Show 12 quoted lines

> On Thu, Mar 28, 2013 at 04:34:19PM +0100, Michael Haggerty wrote:
>
>> Is there a simple way to verify an object name more strictly and convert
>> it to an SHA1?  I can only think of solutions that require two commands,
>> like
>> 
>>     git cat-file -e $ARG && git rev-parse --verify $ARG
>
> Is the rev-parse line doing anything there? If $ARG does not resolve to
> a sha1, then wouldn't cat-file have failed?
>
> -Peff

You could force rev-parse to resolve the input to an existing object, with something like this:

	git rev-parse --verify "$ARG^{}"

It will unwrap a tag, so the output may end up pointing at a object that is different from $ARG in such a case.

But what is the purpose of turning a random string to a random 40-hex in the first place?