Re: [PATCH v2.5 2/2] tag: prevent nested tags

From: Jeff King <peff@peff.net>
Date: Apr 4, 2019, 22:12 UTC
Message-ID: <20190404221208.GA30798@sigill.intra.peff.net>
In-Reply-To: <xmqqef6he8sh.fsf@gitster-ct.c.googlers.com>

On Fri, Apr 05, 2019 at 06:54:06AM +0900, Junio C Hamano wrote:

Show 20 quoted lines

> Jeff King <peff@peff.net> writes:
> 
> > but you have to take pretty specific steps to get a tag of a blob or
> > tree, like:
> >
> >   git tag mytag HEAD:path
> >
> > or
> >
> >   git tag mytag HEAD^{tree}
> 
> And the way to ask for commit and tag are
> 
>     git tag mytag master
>     git tag mytag v1.0.0
> 
> I do not see why only the last one should either be forbidden or
> automaticallly peel.  Each of these four names an object of a
> specific type, and singling out a tag as "curious" makes the
> interface uneven.

My point is that it's easy to accidentally tag a tag. It's not easy to accidentally tag a tree. The counter example would be something that looks as easy as your "git tag mytag v1.0.0" but actually tags a tree. I couldn't think of one.

I do buy the argument that arguing for safety valves from a point of "what's the easiest mistake to make in our current interface" might not be the best one. It yields a set of operations that aren't necessarily sensible or orthogonal with respect to the underlying reality of what's possible and what's reasonable. Which I think is the point you're making.

-Peff