Re: [PATCH 6/9] difftool: replace system call with Git::command_noisy

[Tim Henigan <tim.henigan@gmail.com>]

On Fri, Mar 16, 2012 at 10:48 PM, David Aguilar <davvid@gmail.com> wrote:
> On Fri, Mar 16, 2012 at 6:59 PM, Tim Henigan <tim.henigan@gmail.com> wrote:
>
> In general, I am a little nervous about having difftool copy worktree
> content somewhere temporary only to copy it back in later.  Is there
> some way to make the diff machinery reuse the worktree?  I was under
> the impression that we could do some GIT_INDEX tricks to do it, though
> I will admit that I did not read that suggestion in depth, nor did I
> grasp whether this was the problem it was meant to address.

I have not been able to find any other way to do it.  The GIT_INDEX
trick allows the tmp directories to be built using 'git update-index'
and 'git checkout-index', but they offer no help for this problem.

If we use the working tree directory as one of the diff targets, then
all the files in the working directory would be included in the
diff...unless there was some way to remove the files that aren't part
of the diff from the working tree.  However at that point, I don't
think the solution would be any better (i.e. deleting files from the
working tree and then checking them back out is no better than copying
files to the tmp dir and back again).

The only other option I can think of is to build a complete copy of
the repo in the tmp directory for comparison against the working tree.
 However, this could obviously lead to resource/performance problems
on large repos.

I am open to suggestions, but I have not found any better solution.