Re: [PATCH] Display change history as a diff between two dirs

[Roland Kaufmann <rlndkfmn+git@gmail.com>]

On Tue, Nov 1, 2011 at 04:49, Junio C Hamano <gitster@pobox.com> wrote:
> Roland Kaufmann <rlndkfmn+git@gmail.com> writes:
>> Would it be better to have yet another configuration available for
>> this option instead of reusing the existing infrastructure for `git
>> difftool`?

> It probably is OK for "git diff --dirdiff" to use GIT_EXTERNAL_TREEDIFF if
> and only if GIT_EXTERNAL_DIFF is not defined, and use GIT_EXTERNAL_DIFF
> otherwise. People who have GIT_EXTERNAL_DIFF set to a tool capable of
> handing directory pair can just add "--dirdiff" to the command line, and

Did you perhaps mean the other way around: GIT_EXTERNAL_TREEDIFF
if set, and GIT_EXTERNAL_DIFF otherwise?

I will revise the patch to incorporate that, and at the same time fix
the isempty
function (it can be done simpler).

>>> It also is not clear what could be used in "$@". Obviously you would
>>>  not want things like "-U20" and "--stat" fed to the first "list of
>>> paths" phase, but there may be some options you may want to give to
>>> the inner "external diff" thing.

>> Ideally, it should work the same way as `git difftool`.

> I am not so sure about that; difftool is another way to drive a tool one
> filepair at a time. You want to drive a tool that takes them as two _sets_
> of files, one in each directory.

I was thinking about the behaviour when you send options that are not
applicable to files at all, such as "--stat". In that case, it just stops after
`git diff`. Options that only applies to one file and not to a set
have I admittedly
not thought about (yet).

-- 
   Roland.