Add new test to ensure git-merge handles more than 25 refs.

The old shell version handled only 25 refs but we no longer have this
limitation. Add a test to make sure this limitation will not be
introduced again in the future.

Signed-off-by: Miklos Vajna <vmiklos@frugalware.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t7602-merge-octopus-many.sh

@@ -0,0 +1,52 @@
+#!/bin/sh
+
+test_description='git-merge
+
+Testing octopus merge with more than 25 refs.'
+
+. ./test-lib.sh
+
+test_expect_success 'setup' '
+	echo c0 > c0.c &&
+	git add c0.c &&
+	git commit -m c0 &&
+	git tag c0 &&
+	i=1 &&
+	while test $i -le 30
+	do
+		git reset --hard c0 &&
+		echo c$i > c$i.c &&
+		git add c$i.c &&
+		git commit -m c$i &&
+		git tag c$i &&
+		i=`expr $i + 1` || return 1
+	done
+'
+
+test_expect_failure 'merge c1 with c2, c3, c4, ... c29' '
+	git reset --hard c1 &&
+	i=2 &&
+	refs="" &&
+	while test $i -le 30
+	do
+		refs="$refs c$i"
+		i=`expr $i + 1`
+	done
+	git merge $refs &&
+	test "$(git rev-parse c1)" != "$(git rev-parse HEAD)" &&
+	i=1 &&
+	while test $i -le 30
+	do
+		test "$(git rev-parse c$i)" = "$(git rev-parse HEAD^$i)" &&
+		i=`expr $i + 1` || return 1
+	done &&
+	git diff --exit-code &&
+	i=1 &&
+	while test $i -le 30
+	do
+		test -f c$i.c &&
+		i=`expr $i + 1` || return 1
+	done
+'
+
+test_done