Re: [PATCH v3 1/4] git-cherry-pick: add allow-empty option

[Neil Horman <nhorman@tuxdriver.com>]

On Tue, Apr 10, 2012 at 12:32:18PM -0700, Junio C Hamano wrote:
> Neil Horman <nhorman@tuxdriver.com> writes:
> 
> > On Tue, Apr 10, 2012 at 09:45:46AM -0700, Junio C Hamano wrote:
> > ...
> >>  (2) The message is given by the "git commit" command.  "If the commit was
> >>      created empty" looks confusing.  Even though I can understand that
> > Its coded within the git commit command code, but is only ever displayed if
> > whence is GIT_CHERRY_PICK, so as far as I can see, from a users perspective,
> > this will only be seen if they type git cherry-pick on the command line.
> 
> Here is what I tried, and I think you are wrong.
> 
> 	$ git cherry-pick $some_commit
>         ... conflicts ...
>         $ edit so that the working tree matches HEAD
>         $ git commit -a
>         ... message from status ...
>         THE ADVICE IN QUEWSTION COMES HERE!!!
> 
> 
Ok, I admit I didn't really think of that case, but that seems to me to be the
trivial case, which is unlikely to be encountered.  If you do a git cherry-pick and
have conflicts, you by definition don't have a commit that is resolved to empty
(at least not without manual intervention), nor do you have a commit which was
initially empty.  You really have to go out of your way to take a commit that
conflicts, make it empty, and then commit it without realizing that its empty.

I agree that seeing advice regarding git cherry-pick when you run git commit is
awkward, but its no worse than seeing advice indicating you should run git
commit when you run git cherry-pick (i.e. the case in which you run git
cherry-pick <C>, where <C> is empty an not fast-forward-able.

Perhaps whats called for here is and advice differentiator?  I.e if git commit
is run directly from the command line, issue advice relating to using git commit
--allow-empty, otherwise issue advice relating to git cherry-pick.

I think we could do that by looking at the parent process at run time, unless
theres a good way to differentiate by the sate information in .git

Thoughts?
Neil