Re: Is --filter-print-omitted correct/used/needed?

From: Christian Couder <christian.couder@gmail.com>
Date: Jun 7, 2019, 06:38 UTC
Message-ID: <CAP8UFD2Kyq9nrAnoj3AxQyLgiGHycLEdJbJOQx_stsepsqmX4g@mail.gmail.com>
In-Reply-To: <CAJoAoZktk-w40MEsRZesvkX23Xn2uMUPiO_cMHa=-xfdyVHCWg@mail.gmail.com>

On Thu, Jun 6, 2019 at 10:18 PM Emily Shaffer <emilyshaffer@google.com> wrote:

Show 7 quoted lines

> I grepped the Git source and found that we only provide a non-NULL
> "omitted" when someone calls "git rev-list --filter-print-omitted",
> which we verify with a simple test case for "blobs:none", in which
> case the "border" objects which were omitted must be the same as all
> objects which were omitted (since blobs aren't pointing to anything
> else). I think if we had written a similar test case with some trees
> we expect to omit we might have noticed sooner.

It seems that --filter-print-omitted was introduced in caf3827e2f (rev-list: add list-objects filtering support, 2017-11-21) so I cc'ed Jeff.

[...]

> So, what do we use --filter-print-omitted for? Is anybody needing it?
> Or do we just use it to verify this one test case? Should we fix it,
> or get rid of it, or neither?

In caf3827e2f there is:

    This patch introduces handling of missing objects to help
    debugging and development of the "partial clone" mechanism,
    and once the mechanism is implemented, for a power user to
    perform operations that are missing-object aware without
    incurring the cost of checking if a missing link is expected.

So I would say that if you think that --filter-print-omitted doesn't help in debugging or development, and can even be confusing, and that it also doesn't help performance for power users or anyone else, then it would make sense to remove it, unless you find a way to make it fulfill its original goals, or maybe other worthwhile goals.