t7510: add test cases for non-absolute gpg program

These cases cover scenarios where `gpg.program` is set as a program in
`$PATH` or as a path relative to the user's home directory.

Signed-off-by: Jonas Brandstötter <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: 424ever

t/t7510-signed-commit.sh

@@ -449,7 +449,17 @@ test_expect_success 'custom `gpg.program`' '
 
 	test_must_fail env LET_GPG_PROGRAM_FAIL=1 \
 	git commit -S --allow-empty -m must-fail 2>err &&
-	grep zOMG err
+	grep zOMG err &&
+
+	# `gpg.program` starts with `~`, the path should be interpreted to be relative to `$HOME`
+	test_config gpg.program "~/fake-gpg" &&
+	env HOME="$(pwd)" \
+	git commit -S --allow-empty -m signed-commit &&
+
+	# `gpg.program` does not specify an absolute path, it should find a program in `$PATH`
+	test_config gpg.program "fake-gpg" &&
+	env PATH="$(pwd):$PATH" \
+	git commit -S --allow-empty -m signed-commit
 '
 
 test_done