t1517: more coverage for commands that work without repository

While most of the commands in Git suite are designed to do useful
things in Git repositories, some commands are also usable outside
any repository.  Building on top of an earlier work abece6e (t1517:
test commands that are designed to be run outside repository,
2024-05-20) that adds tests for such commands, let's give coverage
to some more commands.

This patch covers commands whose code has hits for

    $ git grep setup_git_directory_gently

and passes a pointer to nongit_ok variable it uses to allow it to
run outside a Git repository, but mostly they are tested only to see
that they start up (as opposed to dying with "not in a git
repository" complaint).  We may want to update them to actually do
something useful later, but this would at least help us catch
regressions by mistake.

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

Author: gitster

t/t1517-outside-repo.sh

@@ -56,4 +56,56 @@ test_expect_success 'grep outside repository' '
 	test_cmp expect actual
 '
 
+test_expect_success 'imap-send outside repository' '
+	test_config_global imap.host imaps://localhost &&
+	test_config_global imap.folder Drafts &&
+
+	echo nothing to send >expect &&
+	test_must_fail git imap-send -v </dev/null 2>actual &&
+	test_cmp expect actual &&
+
+	(
+		cd non-repo &&
+		test_must_fail git imap-send -v </dev/null 2>../actual
+	) &&
+	test_cmp expect actual
+'
+
+test_expect_success 'check-ref-format outside repository' '
+	git check-ref-format --branch refs/heads/xyzzy >expect &&
+	nongit git check-ref-format --branch refs/heads/xyzzy >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'diff outside repository' '
+	echo one >one &&
+	echo two >two &&
+	test_must_fail git diff --no-index one two >expect.raw &&
+	(
+		cd non-repo &&
+		cp ../one . &&
+		cp ../two . &&
+		test_must_fail git diff one two >../actual.raw
+	) &&
+	# outside repository diff falls back to SHA-1 but
+	# GIT_DEFAULT_HASH may be set to sha256 on the in-repo side.
+	sed -e "/^index /d" expect.raw >expect &&
+	sed -e "/^index /d" actual.raw >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'stripspace outside repository' '
+	nongit git stripspace -s </dev/null
+'
+
+test_expect_success 'remote-http outside repository' '
+	test_must_fail git remote-http 2>actual &&
+	test_grep "^error: remote-curl" actual &&
+	(
+		cd non-repo &&
+		test_must_fail git remote-http 2>../actual
+	) &&
+	test_grep "^error: remote-curl" actual
+'
+
 test_done