Add new test to ensure git-merge handles pull.twohead and pull.octopus

Test if the given strategies are used and test the case when multiple
strategies are configured using a space separated list.

Also test if the best strategy is picked if none is specified.  This is
done by adding a simple test case where recursive detects a rename, but
resolve does not, and verify that finally merge will pick up the
previous.

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

t/t7601-merge-pull-config.sh

@@ -0,0 +1,129 @@
+#!/bin/sh
+
+test_description='git-merge
+
+Testing pull.* configuration parsing.'
+
+. ./test-lib.sh
+
+test_expect_success 'setup' '
+	echo c0 >c0.c &&
+	git add c0.c &&
+	git commit -m c0 &&
+	git tag c0 &&
+	echo c1 >c1.c &&
+	git add c1.c &&
+	git commit -m c1 &&
+	git tag c1 &&
+	git reset --hard c0 &&
+	echo c2 >c2.c &&
+	git add c2.c &&
+	git commit -m c2 &&
+	git tag c2 &&
+	git reset --hard c0 &&
+	echo c3 >c3.c &&
+	git add c3.c &&
+	git commit -m c3 &&
+	git tag c3
+'
+
+test_expect_success 'merge c1 with c2' '
+	git reset --hard c1 &&
+	test -f c0.c &&
+	test -f c1.c &&
+	test ! -f c2.c &&
+	test ! -f c3.c &&
+	git merge c2 &&
+	test -f c1.c &&
+	test -f c2.c
+'
+
+test_expect_success 'merge c1 with c2 (ours in pull.twohead)' '
+	git reset --hard c1 &&
+	git config pull.twohead ours &&
+	git merge c2 &&
+	test -f c1.c &&
+	! test -f c2.c
+'
+
+test_expect_success 'merge c1 with c2 and c3 (recursive in pull.octopus)' '
+	git reset --hard c1 &&
+	git config pull.octopus "recursive" &&
+	test_must_fail git merge c2 c3 &&
+	test "$(git rev-parse c1)" = "$(git rev-parse HEAD)"
+'
+
+test_expect_success 'merge c1 with c2 and c3 (recursive and octopus in pull.octopus)' '
+	git reset --hard c1 &&
+	git config pull.octopus "recursive octopus" &&
+	git merge c2 c3 &&
+	test "$(git rev-parse c1)" != "$(git rev-parse HEAD)" &&
+	test "$(git rev-parse c1)" = "$(git rev-parse HEAD^1)" &&
+	test "$(git rev-parse c2)" = "$(git rev-parse HEAD^2)" &&
+	test "$(git rev-parse c3)" = "$(git rev-parse HEAD^3)" &&
+	git diff --exit-code &&
+	test -f c0.c &&
+	test -f c1.c &&
+	test -f c2.c &&
+	test -f c3.c
+'
+
+conflict_count()
+{
+	eval $1=`{
+		git diff-files --name-only
+		git ls-files --unmerged
+	} | wc -l`
+}
+
+# c4 - c5
+#    \ c6
+#
+# There are two conflicts here:
+#
+# 1) Because foo.c is renamed to bar.c, recursive will handle this,
+# resolve won't.
+#
+# 2) One in conflict.c and that will always fail.
+
+test_expect_success 'setup conflicted merge' '
+	git reset --hard c0 &&
+	echo A >conflict.c &&
+	git add conflict.c &&
+	echo contents >foo.c &&
+	git add foo.c &&
+	git commit -m c4 &&
+	git tag c4 &&
+	echo B >conflict.c &&
+	git add conflict.c &&
+	git mv foo.c bar.c &&
+	git commit -m c5 &&
+	git tag c5 &&
+	git reset --hard c4 &&
+	echo C >conflict.c &&
+	git add conflict.c &&
+	echo secondline >> foo.c &&
+	git add foo.c &&
+	git commit -m c6 &&
+	git tag c6
+'
+
+# First do the merge with resolve and recursive then verify that
+# recusive is choosen.
+
+test_expect_success 'merge picks up the best result' '
+	git config pull.twohead "recursive resolve" &&
+	git reset --hard c5 &&
+	git merge -s resolve c6
+	conflict_count resolve_count &&
+	git reset --hard c5 &&
+	git merge -s recursive c6
+	conflict_count recursive_count &&
+	git reset --hard c5 &&
+	git merge c6
+	conflict_count auto_count &&
+	test "$auto_count" = "$recursive_count" &&
+	test "$auto_count" != "$resolve_count"
+'
+
+test_done