Re: [PATCH v2 0/3] rev-parse and "--"

From: Jonathan Nieder <jrnieder@gmail.com>
Date: Dec 9, 2013, 19:12 UTC
Message-ID: <20131209191224.GR29959@google.com>
In-Reply-To: <xmqqmwk9zvyy.fsf@gitster.dls.corp.google.com>

Junio C Hamano wrote:

Show 6 quoted lines

>>                                      So maybe we are doing a favor by
>> calling out the problem; if they want a rev, they should be using
>> "--verify" (or "--").
>
> I tend to agree with the reasoning in the last sentence. Let's cook
> it for a while and see what happens.

Isn't this essentially breaking a contract that would have been relied on by any script that used "git rev-parse HEAD~3..HEAD"? Worse, it's breaking that contract in a way that no one would notice until they are asked to manipulate a worktree with a file named 'HEAD~3..HEAD' --- in other words, the breakage it introduces is painfully subtle.

I agree that "git rev-parse HEAD" is better written as "git rev-parse --verify HEAD" and hence not so much worth worrying about, but I don't find it easy to believe that people should have anticipated this change and added a trailing "--" to more complex rev-parse expressions.

So to be clear, I think unless it is protected by a new option, this is a bad idea.

Hope that helps, Jonathan