Re: [PATCH] t/gpg: simplify test for unknown key

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

On Fri, Jan 07 2022, Fabian Stelzer wrote:

> To test for a key that is completely unknown to the keyring we need one
> to sign the commit with. This was done by generating a new key and not
> add it into the keyring. To avoid the key generation overhead and
> problems where GPG did hang in CI during it, switch GNUPGHOME to an
> empty directory instead, therefore making all used keys unknown for this
> single `verify-commit` call.
>
> Reported-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
> Signed-off-by: Fabian Stelzer <fs@gigacodes.de>
> ---
> This was reported by Ævar in <211222.86ilvhpbl0.gmgdl@evledraar.gmail.com>.
> Just using an empty keyring / gpg homedir should achieve the same effect and 
> keeps the stress of generating a gpg key out of the CI.

Thanks, it would be great to have this in and before v2.35.0. I've run
into several boxes (on the GCC farm) that hang without this patch.

>  t/t7510-signed-commit.sh | 22 ++--------------------
>  1 file changed, 2 insertions(+), 20 deletions(-)
>
> diff --git a/t/t7510-signed-commit.sh b/t/t7510-signed-commit.sh
> index 9882b69ae2..2d38580847 100755
> --- a/t/t7510-signed-commit.sh
> +++ b/t/t7510-signed-commit.sh
> @@ -71,25 +71,7 @@ test_expect_success GPG 'create signed commits' '
>  	git tag eleventh-signed $(cat oid) &&
>  	echo 12 | git commit-tree --gpg-sign=B7227189 HEAD^{tree} >oid &&
>  	test_line_count = 1 oid &&
> -	git tag twelfth-signed-alt $(cat oid) &&
> -
> -	cat >keydetails <<-\EOF &&
> -	Key-Type: RSA
> -	Key-Length: 2048
> -	Subkey-Type: RSA
> -	Subkey-Length: 2048
> -	Name-Real: Unknown User
> -	Name-Email: unknown@git.com
> -	Expire-Date: 0
> -	%no-ask-passphrase
> -	%no-protection
> -	EOF
> -	gpg --batch --gen-key keydetails &&
> -	echo 13 >file && git commit -a -S"unknown@git.com" -m thirteenth &&
> -	git tag thirteenth-signed &&
> -	DELETE_FINGERPRINT=$(gpg -K --with-colons --fingerprint --batch unknown@git.com | grep "^fpr" | head -n 1 | awk -F ":" "{print \$10;}") &&
> -	gpg --batch --yes --delete-secret-keys $DELETE_FINGERPRINT &&
> -	gpg --batch --yes --delete-keys unknown@git.com
> +	git tag twelfth-signed-alt $(cat oid)
>  '
>  
>  test_expect_success GPG 'verify and show signatures' '
> @@ -129,7 +111,7 @@ test_expect_success GPG 'verify and show signatures' '
>  '
>  
>  test_expect_success GPG 'verify-commit exits failure on unknown signature' '
> -	test_must_fail git verify-commit thirteenth-signed 2>actual &&
> +	GNUPGHOME=./empty_home test_must_fail git verify-commit initial 2>actual &&

Before I noticed this thread (I looked at
https://lore.kernel.org/git/20211230111038.jtoqytdhkilv2732@fs/ first,
and the In-Reply-To chain wasn't connected) I was about to submit
exactly this patch for you but with:

	-       test_must_fail git verify-commit thirteenth-signed 2>actual &&
	+       test_must_fail env GNUPGHOME="$GNUPGHOME_NOT_USED" git verify-commit initial 2>actual &&

Both of those are probably a good thing to do here. I.e.:

 1. Didn't we have portability issues with "ENV_VAR=VALUE shell_function ..." ?
 2. You're pointing to a nonexisting ./empty_home, but shouldn't we use
    $GNUPGHOME_NOT_USED? The existing "show unknown signature with custom format"
    test in the same file does that.