Re: [PATCH v3 4/4] tag: use pgp_verify_function in tag -v call

[Santiago Torres <santiago@nyu.edu>]

On Mon, Apr 04, 2016 at 09:38:54AM -0400, Jeff King wrote:
> On Mon, Apr 04, 2016 at 12:12:04AM -0400, Santiago Torres wrote:
> 
> > > As a side note, it might actually be an improvement for pgp_verify_tag
> > > to take a sha1 (so that git-tag is sure that it is verifying the same
> > > object that it is printing), but that refactoring should probably come
> > > separately, I think.
> > 
> > Just to be sure, this refactoring is something we should still include
> > in this set of patches, right? I think that otherwise we'd lose the
> > desambigutaion that git tag -v does in this patch.
> 
> I think it can be part of this series, but doesn't have to be. As I
> understand it, the current code is just handing the name to the `git
> verify-tag` process, so if we continue to do so, that would be OK.

IIRC, the current code for git tag -v hands the hex-representation[1] of
the sha1 to git verify-tag --- I believe that's related to the
desamgibuation issue I've seen people discuss.  I think this behavior is
lost unless we add this on top of the patch.

> 
> > I also think that most of the rippling is gone if we use and adaptor as
> > you suggested. Should I add a patch on top of this to support a sha1 as
> > part for gpg_verify_tag()?
> 
> Yes, though I'd generally advise against a function taking either a name or
> a sha1, and ignoring the other option. That often leads to confusing
> interfaces for the callers. Instead, perhaps just take the sha1, and let
> the caller do the get_sha1() themselves. Or possibly provide two
> functions, one of which is a convenience to translate the name to sha1
> and then call the other.

I think the former sounds easier. I can replace the name argument and
move the sha1-resolution code to in verify-tag. git tag -v already
resolves the tagname to a sha1, so it is easier there.

Does this sound reasonable? 

Thanks!
-Santiago

[1] https://git.kernel.org/cgit/git/git.git/tree/builtin/tag.c#n109