tests: avoid nonportable {foo,bar} glob

Unlike bash and ksh, dash and busybox ash do not support brace
expansion (as in 'echo {hello,world}').  So when dash is sh,
t6009.13 (set up dodecapus) ends up pass a string beginning with
"root{1,2," to "git merge" verbatim and the test fails.

Fix it by introducing a variable to hold the list of parents for
the dodecapus and populating it in a more low-tech way.

While at it, simplify a little by combining this setup code with the
test it sets up for.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t6009-rev-list-parent.sh

@@ -112,20 +112,20 @@ test_expect_success 'rev-list override and infinities' '
 	check_revlist "--max-parents=0 --min-parents=1 --no-min-parents" one five
 '
 
-test_expect_success 'set up dodecapus' '
+test_expect_success 'dodecapus' '
 
+	roots= &&
 	for i in 1 2 3 4 5 6 7 8 9 10 11
 	do
-		git checkout -b root$i five || return
-		test_commit $i || return
+		git checkout -b root$i five &&
+		test_commit $i &&
+		roots="$roots root$i" ||
+		return
 	done &&
 	git checkout master &&
 	test_tick &&
-	git merge -m dodecapus root{1,2,3,4,5,6,7,8,9,10,11} &&
-	git tag dodecapus
-'
-
-test_expect_success 'test with dodecapus' '
+	git merge -m dodecapus $roots &&
+	git tag dodecapus &&
 
 	check_revlist "--min-parents=4" dodecapus tetrapus &&
 	check_revlist "--min-parents=8" dodecapus &&