Re: Staging commits with visual diff tools?

[Jeff King <peff@peff.net>]

On Tue, May 26, 2015 at 09:50:49PM +0100, John Lee wrote:

> Does anybody have code to stage commits using a the visual diff/merge tools
> supported by git-difftool?  Is there support in git itself somewhere, even?
> 
> I'm looking for something functionally similar to git add -p
> 
> Looking at the git-difftool source I can see how to write a command to do
> it, but wanted to check if it had already been implemented.
> 
> Did I miss a way that already exists?

git-gui has a visual staging tool, and I think some other git interfaces
do, too (e.g., tig). But I don't think there is a way to interact with
an arbitrary 3rd-party diff tool. I would think doing so would depend on
the diff tool itself; what facility does it provide for picking lines
or a hunk out of a diff and communicating it back to git to stage?

If you are interested in looking further, see how the %patch_mode hash
is defined in git-add--interactive.perl. Specifically, note that "add
-p" is just one case: diff against the index and apply with "apply
--cached". But once you have a separate tool for picking hunks, you
should be able to drop in the different DIFF/APPLY pairs to implement
"checkout -p", etc.

-Peff