Re: [PATCH v2 1/2] update-index: optionally leave skip-worktree entries alone

[Johannes Schindelin <Johannes.Schindelin@gmx.de>]

Hi Junio,

On Wed, 30 Oct 2019, Junio C Hamano wrote:

> "Johannes Schindelin via GitGitGadget" <gitgitgadget@gmail.com>
> writes:
>
> > From: Johannes Schindelin <johannes.schindelin@gmx.de>
> >
> > While `git update-index` mostly ignores paths referring to index entries
> > whose skip-worktree bit is set, in b4d1690df11 (Teach Git to respect
> > skip-worktree bit (reading part), 2009-08-20), for reasons that are not
> > entirely obvious, the `--remove` option was made special: it _does_
> > remove index entries even if their skip-worktree bit is set.
> >
> > Seeing as this behavior has been in place for a decade now, it does not
> > make sense to change it.
>
> If this were end-user facing Porcelain behaviour, even it is a
> decade old, the story would have been different, but given that it
> is in an obscure corner in a plumbing command, I agree that it does
> not make sense to even transition the default over releases.
>
> > +test_expect_success '--ignore-skip-worktree-entries leaves worktree alone' '
> > +	test_commit geroff-me &&
> > +	git update-index --skip-worktree geroff-me.t &&
> > +	rm geroff-me.t &&
>
> I do not see a need to swear with a sample file name.  It may make
> sense to use words that relate to what the test is checking (e.g.
> skip-me or something like that), but otherwise meaningless filenames
> used in other tests (like 1, 2, etc) would be more in line with the
> existing tests.

I changed this locally to `keep-me`. But then I saw that you merged this
patch pair to `next` already... Do you want an add-on patch, or revert
it out of `next`, or leave as-is?

I'd like to know because I still want to merge this into Git for Windows
v2.24.0-rc2, and I would love to deviate as little as possible from
git.git there.

> > +
> > +	: ignoring the worktree &&
> > +	git update-index --remove --ignore-skip-worktree-entries geroff-me.t &&
> > +	git diff-index --cached --exit-code HEAD &&
>
> HEAD has it, working tree does not, and the one in the index should
> have been kept thanks to the new option added by this patch.  Makes
> sense.
>
> > +	: not ignoring the worktree, a deletion is staged &&
> > +	git update-index --remove geroff-me.t &&
> > +	test_must_fail git diff-index --cached --exit-code HEAD
>
> Testing the other side of the coin (i.e. adding the new feature did
> not accidentally stop the command from removing by default) is good;
> "should have no difference" was a good test for the other side, but
> in contrast, "should have some difference" is a very loose test when
> the difference we want to see is that the particular path gets removed
> and no other changes.

True. I changed it to `test_must_fail git rev-parse :keep-me` locally
(to test for the staged deletion, although it just occurred to me that I
would rather want to add the `--diff-filter=D` option and filter by the
file name to really verify that a deletion was staged), but again, I
noticed that you already merged this to `next`...

So: revert out of `next`, add-on patch, or leave as-is?

Thanks,
Dscho

>
> > +'
> > +
> >  #TODO test_expect_failure 'git-apply adds file' false
> >  #TODO test_expect_failure 'git-apply updates file' false
> >  #TODO test_expect_failure 'git-apply removes file' false
>
>