Re: [PATCH] docs: checking out using @{-N} can lead to detached state

From: Kaartic Sivaraam <kaartic.sivaraam@gmail.com>
Date: Nov 20, 2017, 15:18 UTC
Message-ID: <52a6a1e5-c444-0bad-2558-e326ae170a3c@gmail.com>
In-Reply-To: <xmqqpo8dn1jd.fsf@gitster.mtv.corp.google.com>

On Monday 20 November 2017 07:39 AM, Junio C Hamano wrote:

Show 12 quoted lines

> Kaartic Sivaraam <kaartic.sivaraam@gmail.com> writes:
> 
> After the first paragraph explains what happens during "checkout
> <branch>" and goes from the normal case where <branch> is really a
> branch name to an arbitrary commit (where "detaching" needs to be
> mentioned), a commit before 75d6e552a added mention of @{-N} and
> made it appear as if it were a reference to a commit (i.e. not a
> branch name) and that was why it said "As a special case" and
> mentioned "detaching".  The problem lies in a lot older one,
> 696acf45 ("checkout: implement "-" abbreviation, add docs and
> tests", 2009-01-17).
>

Thanks for the analysis. Just to be sure, I referred to 75d6e552a just to back up my claim, was that intention clear in my log message? Also, should I mention the old commit (696acf45) also in the log message?

Show 12 quoted lines

> 
> So perhaps we should start from dropping that "As a special case".
> 
>      You can also use the `"@{-N}"` syntax to refer to the thing the N-th
>      last "git checkout" operation checked out; if it was a branch, that
>      branch is checked out, and otherwise the HEAD is detached at the
>      commit.  You may also specify `-` which is synonymous to `"@{-1}"`.
> 
> or something like that.  If we do so, we'd further need to tweak "As
> a further special case", as this rewrite makes it clear that "@{-N}"
> is not a special case at all (instead it is merely a different way
> to spell <branch> or <commit> that is already covered).

Good point. I did use your rewritten message but with some modification,

     You can also use the `@{-N}` syntax to refer to the N-th last
     branch/commit checked out using "git checkout" operation. You may
     also specify `-` which is synonymous to `@{-1}`.

I tweaked the first part of the first sentence and dropped the last part of it just to avoid redundancy with the paragraph above it. Hope that sounds good. If it seems to need some modification, let me know.

Thanks, Kaartic