Re: [RFC/PATCH] Teach git mergetool to use custom commands defined at config time

[Junio C Hamano <gitster@pobox.com>]

Theodore Tso <tytso@MIT.EDU> writes:

> I have no objection to a generic mechanism, but I don't see the value
> of Charles suggestion to rip out support for the existing tools
> supported by git-mergetool.

I missed that suggestion but I agree removing existing support
would not make much sense.

> I think it *would* be better to use %(foo) extrapolation that
> environment variables, so that it's not required for users to write
> shell scripts unless absolutely necessary.

Hmm, although I do not have strong opinions either way, I think
the necessary interface is narrow enough that we could use
environment variables here.  Charles's implementation does
"eval" but it is easy to replace it to run the custom command
after exporting the necessary variables, isn't it?

> When we get around to rewriting git-mergetool in C, it might make
> sense to put the tool support in the various shell scripts that are
> installed in the git helper binary directory (i.e.,
> git-mergetool-kdiff3, git-mergetool-meld, etc.)  That would make it
> easier for users to create new shell scripts to support new tools if
> necessary.

Yup.