Re: [PATCH 3/3] rev-list: add --allow-missing-tips to be used with --missing=...

[Linus Arver <linusa@google.com>]

Christian Couder <christian.couder@gmail.com> writes:

> On Thu, Feb 1, 2024 at 10:27 PM Junio C Hamano <gitster@pobox.com> wrote:
>>
>> Christian Couder <christian.couder@gmail.com> writes:
>>
>> > When such a command is used to find the dependencies of some objects,
>> > for example the dependencies of quarantined objects, it would be
>> > better if the command would instead consider such missing objects,
>> > especially commits, in the same way as other missing objects.
>> >
>> > If, for example `--missing=print` is used, it would be nice for some
>> > use cases if the missing tips passed as arguments were reported in
>> > the same way as other missing objects instead of the command just
>> > failing.
>> >
>> > Let's introduce a new `--allow-missing-tips` option to make it work
>> > like this.
>>
>> An obvious question is if this even needs to be a new option.  What
>> are expected use cases where --missing=print without this option is
>> beneficial?
>
> I am not sure if such a case is really beneficial but some
> people/script/forges might rely on an error from `git rev-list
> --missing=print` to propagate back an error to some user interface.

I currently learn toward just making the new flag's behavior be absorved
into the existing "--missing=..." flag. Nevertheless, you raise an
interesting concern.

Perhaps a compromise would be to make "--missing=..." learn the new
behavior of this patch as Junio suggested, but to introduce a new flag,
something like "--fail-on-missing-tips" to fail early if any of the tip
commits' objects are missing? That way we could keep the current
"strict" behavior of complaining if we feed rev-list any tips whose
objects are missing. And for the vast majority of cases the
"--missing=..." flag could (intuitively) gracefully handle tips with
missing objects and you wouldn't have to pass in the additional flag.

IOW, make the minority (certainly not majority, I think?) of users who
really need the error propagation use the (new) extra flag, while the
rest of us (including the version of you who was surprised by the
limited behavior of "--missing=...", enough to write this series) don't
have to.

Thanks.