Re: [PATCH 1/7] cat-file: disable object/refname ambiguity check for batch mode

From: Junio C Hamano <gitster@pobox.com>
Date: Jul 15, 2013, 03:45 UTC
Message-ID: <7vk3ksfpum.fsf@alter.siamese.dyndns.org>
In-Reply-To: <20130712092212.GA4859@sigill.intra.peff.net>

Jeff King <peff@peff.net> writes:

Show 11 quoted lines

>> To cat-file we could add an option like "--sha1-only" or "--literal" or
>> "--no-dwim" (... better names are failing me) which would skip *all*
>> dwimming of 40-character strings.  It would also assume that any shorter
>> strings are abbreviated SHA-1s and fail if they are not.  This would be
>> a nice feature by itself ("these are object names, dammit, and don't try
>> to tell me differently!") and would have the additional small advantage
>> of speeding up lookups of abbreviated SHA-1s, which (regardless of your
>> patch) otherwise go through the whole DWIM process.
>
> I can see in theory that somebody might want that, but I am having a
> hard time thinking of a practical use.

Would it be a good alternative to call get_sha1_hex() to catch the most common case (reading from rev-list output, for example) and then let the more general get_sha1() to let extended SHA-1 to be handled?

> IOW, it seems like a poor default, and we are choosing it only because
> of backwards compatibility. I guess another option is to switch the
> default with the usual deprecation dance.

I agree that "did you mean the unreadable refname or 40-hex object?" turned on everywhere get_sha1() is called is a very poor default. I wonder if we can limit it only to the end-user input somehow at the API level.