Re: [PATCH 2/2] builtin/verify-tag: do not omit gpg on --format

From: Jeff King <peff@peff.net>
Date: May 9, 2019, 07:44 UTC
Message-ID: <20190509074455.GB24493@sigill.intra.peff.net>
In-Reply-To: <20190427202123.15380-3-santiago@nyu.edu>

On Sat, Apr 27, 2019 at 04:21:23PM -0400, santiago@nyu.edu wrote:

Show 6 quoted lines

> From: Santiago Torres <santiago@nyu.edu>
> 
> The current implementation of git-verify-tag omits the gpg output when
> the --format flag is passed. This may not be useful to users that want
> to see the gpg output *and* --format the output of git verify-tag.
> Instead, respect the --raw flag or the default gpg output.

Yep, this is just the matching change to patch 1. Makes sense.

Show 11 quoted lines

> diff --git a/builtin/verify-tag.c b/builtin/verify-tag.c
> index 6fa04b751a..262e73cb45 100644
> --- a/builtin/verify-tag.c
> +++ b/builtin/verify-tag.c
> @@ -47,15 +47,13 @@ int cmd_verify_tag(int argc, const char **argv, const char *prefix)
>  	if (argc <= i)
>  		usage_with_options(verify_tag_usage, verify_tag_options);
>  
> -	if (verbose)
> +	if (verbose && !format.format)
>  		flags |= GPG_VERIFY_VERBOSE;

Now this one's VERBOSE handling is a bit interesting. Previously we'd set VERBOSE even if we were going to show a format. And then later we just set the OMIT_STATUS bit, leaving VERBOSE in place:

> -		flags |= GPG_VERIFY_OMIT_STATUS;

That _usually_ didn't matter because with OMIT_STATUS, we'd never enter print_signature_buffer(), which is where VERBOSE would usually kick in. But there's another spot we look at it:

  $ grep -nC2 VERBOSE tag.c 
  22-
  23-	if (size == payload_size) {
  24:		if (flags & GPG_VERIFY_VERBOSE)
  25-			write_in_full(1, buf, payload_size);
  26-		return error("no signature found");

So the code prior to your patch actually had another weird behavior. Try this:

  $ git verify-tag -v --format='my tag is %(tag)' v2.21.0
  my tag is v2.21.0

  $ git tag -m bar foo
  $ git verify-tag -v --format='my tag is %(tag)' foo
  object 66395b630f8ca08705b36c359415af8b25da9a11
  type commit
  tag foo
  tagger Jeff King <peff@peff.net> 1557387618 -0400
  
  bar
  error: no signature found

The "-v" only kicks in when there's an error. I think what your patch is doing (consistently ignoring "-v" when there's a format) makes more sense. It may be worth alerting the user when "-v" and "--format" are used together (or arguably we should _always_ show "-v" if the user really asked for it, but it does not make any sense to me for somebody to do so).

Show 6 quoted lines

> -	if (format.format) {
> +	if (format.format)
>  		if (verify_ref_format(&format))
>  			usage_with_options(verify_tag_usage,
>  					   verify_tag_options);
> -	}

This leaves us with a weird doubled conditional (with no braces either!). Maybe:

  if (format.format && verify_ref_format(&format))
	usage_with_options(...);

Other than that, the patch looks good. I think it could use a test in t7030, though.

-Peff