Add test showing git-fetch groks gitfiles

Add a test for two subtly different cases: 'git fetch path/.git'
and 'git fetch path' to confirm that transport recognizes both
paths as git repositories when using the gitfile mechanism.

Signed-off-by: Phil Hord <hordp@cisco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t5601-clone.sh

@@ -206,6 +206,20 @@ test_expect_success 'clone from .git file' '
 	git clone dst/.git dst2
 '
 
+test_expect_success 'fetch from .git gitfile' '
+	(
+		cd dst2 &&
+		git fetch ../dst/.git
+	)
+'
+
+test_expect_success 'fetch from gitfile parent' '
+	(
+		cd dst2 &&
+		git fetch ../dst
+	)
+'
+
 test_expect_success 'clone separate gitdir where target already exists' '
 	rm -rf dst &&
 	test_must_fail git clone --separate-git-dir realgitdir src dst