Re: [PATCH v2 1/2] push: add "--[no-]force-if-includes"

From: Srinidhi Kaushik <shrinidhi.kaushik@gmail.com>
To: Junio C Hamano <gitster@pobox.com>
Cc: git@vger.kernel.org
Subject: Re: [PATCH v2 1/2] push: add "--[no-]force-if-includes"
Date: Sun, 13 Sep 2020 02:55:24 +0530	[thread overview]
Message-ID: <20200912212524.GB55022@mail.clickyotomy.dev> (raw)
In-Reply-To: <xmqq5z8ioo15.fsf@gitster.c.googlers.com>

On 09/12/2020 11:20, Junio C Hamano wrote:
> Srinidhi Kaushik <shrinidhi.kaushik@gmail.com> writes:
> 
> > Add a new option: `--force-if-includes` to `git-push` where forced
> > updates are allowed only if the tip of the remote-tracking ref has
> > been integrated locally, by verifying if the tip of the remote-tracking
> > ref on which a local branch has based on (for a rewrite), is reachable
> > from at least one of the `reflog` entries of the local branch about
> > to be updated by force on the remote.
> >
> > This option can also be used with `--force-with-lease` in setups
> > where the remote-tracking refs of the repository are implicitly
> > updated in the background.
> >
> > If a local branch is based on a remote ref for a rewrite, and if that
> > remote-tracking ref is updated by a push from another repository after
> > it has been checked out locally, force updating that branch to remote
> > with `--force-with-lease[=<refname>[:expect]]` without specifying the
> > "<refname>" or "<expect>" values, can cause the update that happened
> > in-between the checkout and forced push to be lost.
> >
> > Specifying `--force-with-includes` with `--force-with-lease` as an
> > ancillary argument at the time of push, ensures that any new updates
> > to the remote-tracking refs are integrated locally before allowing a
> > forced update. This behavior can enabled by default if the configuration
> > option `push.forceIfIncludesWithLease` is set to `true`.
> 
> This step seems to do too many things at once.  Split into logical
> progression of improvements, or nobody can sensibly review it, I am
> afraid.

OK, I will break the commit up into smaller change-sets in the next
patch.

> > diff --git a/Documentation/config/push.txt b/Documentation/config/push.txt
> > index f5e5b38c68..1b4948faa0 100644
> > --- a/Documentation/config/push.txt
> > +++ b/Documentation/config/push.txt
> > @@ -114,3 +114,11 @@ push.recurseSubmodules::
> >  	specifying '--recurse-submodules=check|on-demand|no'.
> >  	If not set, 'no' is used by default, unless 'submodule.recurse' is
> >  	set (in which case a 'true' value means 'on-demand').
> > +
> > +push.forceIfIncludesWithLease::
> > +	If set to `true`, adds `--force-if-includes` as an ancillary argument
> > +	to `--force-with-lease[=<refname>[:<expect>]]`, when "<refname>" or
> > +	"<expect>" values are unspecified at the time of push.
> > ++
> > +Note: Specifying `--no-force-if-includes` to linkgit:git-push[1] as an
> > +argument during the time of push does _not_ override this configuration.
> 
> I do not see why you still want to link these two unrelated
> features.  I may want to do forced push with lease when I know I am
> rewinding, and I may want to do a if-included force when needed, but
> I do not see why I want to ask the former and implicitly see it also
> trigger the latter.

I am actually thinking of getting rid of the configuration option
altogether. Sadly, I realized that after I sent out the patch.

> I haven't seen the details, but if we severe the (unnecessary?)
> entanglement of these two features, perhaps this patch will become a
> lot smaller and more focused?  I dunno.

Other than the configuration setting (which will be removed), tthe only
parts that overlap are checking to see if "--force-with-lease" specified
with `use_tracking` and `use_tracking_for_test` modes only. The new
option does not modify the "strict" version of "compare-and-swap"
because in that case, it is not needed at all.

However, I think it can be cleaned up a bit more; will look into it.

Thanks.
-- 
Srinidhi Kaushik