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From: Jeff King <peff@peff.net>
To: Junio C Hamano <gitster@pobox.com>
Cc: Duy Nguyen <pclouds@gmail.com>, Git Mailing List <git@vger.kernel.org>
Subject: Re: [BUG] redundant error message
Date: Thu, 5 Dec 2013 16:00:00 -0500	[thread overview]
Message-ID: <20131205210000.GA19617@sigill.intra.peff.net> (raw)
In-Reply-To: <xmqqfvq73vhw.fsf@gitster.dls.corp.google.com>

On Thu, Dec 05, 2013 at 12:15:07PM -0800, Junio C Hamano wrote:

> >> Hmph, it looks like it is following the usual "zero-or-more dashed
> >> options, zero-or-more revs and then zero-or-one double-dash and then
> >> zero-or-more paths" rule to parse the thing.  "foobar" is a file and
> >> not a rev, so "--" should not be there, no?
> >> 
> >> Confused why you think it is not right...
> >
> > Because once you say "--", then all ambiguity goes away, no?
> 
> But it is tricky (not from implementation but from semantics point
> of view) to make rev-parse follow that "-- separates revs and paths"
> rule literally.  The primary use of rev-parse is to convert revs in
> extended SHA-1 expressions into concrete object names, so that
> scripts do not have to worry about having to deal with object names
> in a format that is not 40-hexdecimal.  "git rev-parse foobar --"
> that gives
> 
> 	foobar
>         --
> 
> without any error, because 'foobar' cannot be made into an object
> name, would be behaving in a way unexpected by the calling script,
> no?

Yes, I do expect an error. But it should not be "-- after filename". It
should be "foobar is not a revision".

Thinking on it more, though, the problem is purely limited to wrong
error messages. If "foobar" exists as a rev, we do parse it correctly.
If it does not, we are in the wrong code path, but it _must_ be an error
at that point (either because foobar does not exist as a file, or it
does and has "--" after it).

It would be nice to get the error messages right, though. I do not see
any reason why it could not follow the same steps as "git log",
converting revisions (or throwing an error as appropriate) on the left
side of the "--", and passing through the right side untouched.

-Peff

  reply	other threads:[~2013-12-05 21:00 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-12-05 10:07 [BUG] redundant error message Duy Nguyen
2013-12-05 19:15 ` Jeff King
2013-12-05 20:00   ` Junio C Hamano
2013-12-05 20:03     ` Jeff King
2013-12-05 20:15       ` Junio C Hamano
2013-12-05 21:00         ` Jeff King [this message]
2013-12-05 21:28           ` Jeff King
2013-12-05 21:44             ` Junio C Hamano
2013-12-06 21:12               ` [PATCH 0/2] rev-parse and "--" Jeff King
2013-12-06 21:13                 ` [PATCH 1/2] rev-parse: correctly diagnose revision errors before "--" Jeff King
2013-12-06 21:15                 ` [PATCH 2/2] rev-parse: diagnose ambiguous revision/filename arguments Jeff King
2013-12-06 22:05                   ` [PATCH v2 0/3] rev-parse and "--" Jeff King
2013-12-06 22:05                     ` [PATCH v2 1/3] rev-parse: correctly diagnose revision errors before "--" Jeff King
2013-12-06 23:34                       ` Jonathan Nieder
2013-12-06 22:07                     ` [PATCH v2 2/3] rev-parse: be more careful with munging arguments Jeff King
2013-12-07  0:04                       ` Jonathan Nieder
2013-12-09 21:33                       ` Eric Sunshine
2013-12-06 22:08                     ` [PATCH v2 3/3] rev-parse: diagnose ambiguous revision/filename arguments Jeff King
2013-12-06 23:25                     ` [PATCH v2 0/3] rev-parse and "--" Jonathan Nieder
2013-12-06 23:30                       ` Jeff King
2013-12-09 19:05                     ` Junio C Hamano
2013-12-09 19:12                       ` Jonathan Nieder
2013-12-09 19:23                         ` Jonathan Nieder
2013-12-09 20:48                         ` Junio C Hamano
2013-12-09 20:56                           ` Jonathan Nieder
2013-12-09 21:10                             ` Junio C Hamano
2013-12-06  1:15             ` [BUG] redundant error message Duy Nguyen
2013-12-06 22:13               ` Jeff King

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