Test for local branches being followed with --track

According to the documentation, it is perfectly okay to follow local
branches using the --track option. Introduce a test which checks whether
they behave the same. Currently one test fails.

Signed-off-by: Michael J Gruber <git@drmicha.warpmail.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t6040-tracking-info.sh

@@ -29,7 +29,9 @@ test_expect_success setup '
 		git checkout -b b4 origin &&
 		advance e &&
 		advance f
-	)
+	) &&
+	git checkout -b follower --track master &&
+	advance g
 '
 
 script='s/^..\(b.\)[	 0-9a-f]*\[\([^]]*\)\].*/\1 \2/p'
@@ -56,6 +58,12 @@ test_expect_success 'checkout' '
 	grep "have 1 and 1 different" actual
 '
 
+test_expect_failure 'checkout with local tracked branch' '
+	git checkout master &&
+	git checkout follower >actual
+	grep "is ahead of" actual
+'
+
 test_expect_success 'status' '
 	(
 		cd test &&