Re: git alias question

[David Aguilar <davvid@gmail.com>]

On Thu, Dec 29, 2011 at 9:08 AM, Dave Borowitz <dborowitz@google.com> wrote:
> On Wed, Dec 28, 2011 at 17:27, Michael Horowitz
> <michael.horowitz@ieee.org> wrote:
>> ldiff = "!git diff `git rev-list --reverse -n 2 HEAD -- $1` -- $1"
>
> FWIW, you can also do this as:
>  ldiff = log -p -1 --format=format: --
>
>> ldifft = "!git difftool `git rev-list --reverse -n 2 HEAD -- $1` -- $1"
>
> I don't know that you can do something equivalent with difftool. I
> suppose you could do the above with "GIT_EXTERNAL_DIFF=<some difftool
> wrapper> git ldiff", but that's not very helpful.

difftool cannot be driven by log right now.  It is something we
thought would be helpful in the past:

http://thread.gmane.org/gmane.comp.version-control.git/114269/focus=114367

On 2009-03-23 Junio C Hamano <gitster <at> pobox.com> wrote:
> Perhaps we would want a convenient way for "log -p" or "show -p" to drive
> difftool as a backend?

I think that's exactly it.  difftool wraps diff; a log equivalent
would be quite helpful.

One idea is for difftool to learn a "--log" option to make it wrap log
instead.  I don't know if a diff-like command having a "--log" option
is ideal from a consistency-of-user-interface POV so I'm open to
ideas.  It is convenient, though.  It does seem like difftool would be
a good place to expose this feature.

I'd be interested in the "teach log / show -p about GIT_EXTERNAL_DIFF"
route, if that sounds like a good idea.
-- 
            David