Re: [PATCH 1/1] verify-tag/verify-commit should exit unsuccessfully when signature is not trusted

"brian m. carlson" [off-list ref] writes:

quoted

FWIW, I'm on board with returning non-zero in any case where gpg would.

I think that's probably the best solution overall.

FWIW, I am not married to the current behaviour.  I would not be
surprised if it mostly came by accident and not designed.

There's a bug report
in Debian (https://bugs.debian.org/895048) that requests that behavior
instead of the status quo, and also it's the behavior that's documented:

The last bit is a bit questionable; I think you are reading too much
into the description.

A substitute for gpg.program MUST signal good (or not good)
signature the same way as gpg would with its exit code---that is all
the description says.  It does not say anything about how that exit
code affects the exit status of "tag --verify" and friends that
called gpg.program.

       gpg.program
           Use this custom program instead of "gpg" found on $PATH when
           making or verifying a PGP signature. The program must support
           the same command-line interface as GPG, namely, to verify a
           detached signature, "gpg --verify $file - <$signature" is
           run, and the program is expected to signal a good signature
           by exiting with code 0, and to generate an ASCII-armored
           detached signature, the standard input of "gpg -bsau $key" is
           fed with the contents to be signed, and the program is
           expected to send the result to its standard output.