Re: [PATCH 8/9 v11] difftool: teach difftool to handle directory diffs

From: Tim Henigan <tim.henigan@gmail.com>
Date: Apr 11, 2012, 16:46 UTC
Message-ID: <CAFouetgfPuiYO9xKPGQ1GGjr6JvMXM7et_7oYrWRrg+RMj9mCQ@mail.gmail.com>
In-Reply-To: <CAJDDKr7XXqWBRVXhEenWVcE+7526sYVV821Ytty0xbZBvshd-w@mail.gmail.com>

On Wed, Apr 11, 2012 at 5:02 AM, David Aguilar <davvid@gmail.com> wrote:

Show 10 quoted lines

> On Tue, Apr 10, 2012 at 10:24 AM, Tim Henigan <tim.henigan@gmail.com> wrote:
>> On Mon, Apr 9, 2012 at 8:14 AM, David Aguilar <davvid@gmail.com> wrote:
>>> On Wed, Apr 4, 2012 at 12:21 PM, Tim Henigan <tim.henigan@gmail.com> wrote:
>
> I think the right thing to do would be to not override GIT_DIR at all.
>  I haven't read it deeply enough to know whether it was being
> overridden for a specific reason, but I think it should be safe to
> leave it as-is.
>
> Git.pm ends up overriding these variables itself anyways when calling commands.

I tried to avoid setting $GIT_DIR in earlier versions of the patch. However as discussed here [1], either 'git update-index' or 'git checkout-index' did not work as expected without explicitly setting $GIT_DIR.

If $GIT_DIR is not set, 'update-index' and 'checkout-index' will only work if 'difftool' is called from the repo root. If 'difftool' is called from a subdirectory, then one of the commands fails.

I suspect that when $GIT_INDEX_FILE is set but $GIT_DIR is not, then $GIT_DIR is assumed to be 'pwd'. However, I was not able to prove that.

> The GIT_WORK_TREE check should use $repo->wc_path().  Git.pm's already
> done all the hard work ;-)

I also tried this in an earlier version of the patch. As noted here [2], I found that when 'difftool' was run from a subdirectory of the repo root, '$repo->wc_path()' returned the subdirectory rather than the repo root.

Thinking about this again now, I realize it was a side-effect of $GIT_DIR being set in the script. The man page for git config states that:

    If --git-dir or GIT_DIR is specified but none of --work-tree, GIT_WORK_TREE
    and core.worktree is specified, the current working directory is regarded as
    the top level of your working tree.

So, if I explicitly set $GIT_DIR just for the 'update-index' and 'checkout-index' commands, I need to unset it afterwards. This should allow '$repo->wc_path()' to behave as expected.

[1]: http://thread.gmane.org/gmane.comp.version-control.git/193296/focus=193302 [2]: http://thread.gmane.org/gmane.comp.version-control.git/193601/focus=193603