rev-parse: fix using "--default" with "--verify"

Before this patch, something like:

$ git rev-parse --verify HEAD --default master

did not work, while:

$ git rev-parse --default master --verify HEAD

worked.

This patch fixes that, so that they both work (assuming
HEAD and master can be parsed).

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin-rev-parse.c

@@ -583,6 +583,8 @@ int cmd_rev_parse(int argc, const char **argv, const char *prefix)
 			continue;
 		verify_filename(prefix, arg);
 	}
+	if (verify && revs_count == 1)
+		return 0;
 	show_default();
 	if (verify && revs_count != 1)
 		die_no_single_rev(quiet);

t/t1503-rev-parse-verify.sh

@@ -97,18 +97,17 @@ test_expect_failure '3 no stdout output on error' '
 	test -z "$(git rev-parse --verify $HASH2 HEAD)"
 '
 
-test_expect_success '1 with --default' '
+test_expect_success 'use --default' '
 	git rev-parse --verify --default master &&
 	git rev-parse --verify --default master HEAD &&
 	git rev-parse --default master --verify &&
 	git rev-parse --default master --verify HEAD &&
+	git rev-parse --verify HEAD --default master &&
 	test_must_fail git rev-parse --verify foo --default master &&
 	test_must_fail git rev-parse --default HEAD --verify bar &&
-	test_must_fail git rev-parse --verify --default HEAD baz
-'
-
-test_expect_failure '2 with --default' '
-	git rev-parse --verify HEAD --default master
+	test_must_fail git rev-parse --verify --default HEAD baz &&
+	test_must_fail git rev-parse --default foo --verify &&
+	test_must_fail git rev-parse --verify --default bar
 '
 
 test_done