Merge branch 'mv/merge-in-c'

* mv/merge-in-c:
  reduce_heads(): protect from duplicate input
  reduce_heads(): thinkofix
  Add a new test for git-merge-resolve
  t6021: add a new test for git-merge-resolve
  Teach merge.log to "git-merge" again
  Build in merge
  Fix t7601-merge-pull-config.sh on AIX
  git-commit-tree: make it usable from other builtins
  Add new test case to ensure git-merge prepends the custom merge message
  Add new test case to ensure git-merge reduces octopus parents when possible
  Introduce reduce_heads()
  Introduce get_merge_bases_many()
  Add new test to ensure git-merge handles more than 25 refs.
  Introduce get_octopus_merge_bases() in commit.c
  git-fmt-merge-msg: make it usable from other builtins
  Move read_cache_unmerged() to read-cache.c
  Add new test to ensure git-merge handles pull.twohead and pull.octopus
  Move parse-options's skip_prefix() to git-compat-util.h
  Move commit_list_count() to commit.c
  Move split_cmdline() to alias.c

Conflicts:
	Makefile
	parse-options.c

7 files changed, 371 insertions, 0 deletions

diff --git a/t/t6021-merge-criss-cross.sh b/t/t6021-merge-criss-cross.sh
index 0ab14a6e81..331b9b07d4 100755
--- a/t/t6021-merge-criss-cross.sh
+++ b/t/t6021-merge-criss-cross.sh
@@ -89,4 +89,8 @@ EOF
 
 test_expect_success 'Criss-cross merge result' 'cmp file file-expect'
 
+test_expect_success 'Criss-cross merge fails (-s resolve)' \
+'git reset --hard A^ &&
+test_must_fail git merge -s resolve -m "final merge" B'
+
 test_done
diff --git a/t/t7600-merge.sh b/t/t7600-merge.sh
index d21cd290d3..d4cf6289a4 100755
--- a/t/t7600-merge.sh
+++ b/t/t7600-merge.sh
@@ -465,11 +465,51 @@ test_expect_success 'merge log message' '
 	git merge --no-log c2 &&
 	git show -s --pretty=format:%b HEAD >msg.act &&
 	verify_diff msg.nolog msg.act "[OOPS] bad merge log message" &&
+
 	git merge --log c3 &&
 	git show -s --pretty=format:%b HEAD >msg.act &&
+	verify_diff msg.log msg.act "[OOPS] bad merge log message" &&
+
+	git reset --hard HEAD^ &&
+	git config merge.log yes &&
+	git merge c3 &&
+	git show -s --pretty=format:%b HEAD >msg.act &&
 	verify_diff msg.log msg.act "[OOPS] bad merge log message"
 '
 
 test_debug 'gitk --all'
 
+test_expect_success 'merge c1 with c0, c2, c0, and c1' '
+       git reset --hard c1 &&
+       git config branch.master.mergeoptions "" &&
+       test_tick &&
+       git merge c0 c2 c0 c1 &&
+       verify_merge file result.1-5 &&
+       verify_parents $c1 $c2
+'
+
+test_debug 'gitk --all'
+
+test_expect_success 'merge c1 with c0, c2, c0, and c1' '
+       git reset --hard c1 &&
+       git config branch.master.mergeoptions "" &&
+       test_tick &&
+       git merge c0 c2 c0 c1 &&
+       verify_merge file result.1-5 &&
+       verify_parents $c1 $c2
+'
+
+test_debug 'gitk --all'
+
+test_expect_success 'merge c1 with c1 and c2' '
+       git reset --hard c1 &&
+       git config branch.master.mergeoptions "" &&
+       test_tick &&
+       git merge c1 c2 &&
+       verify_merge file result.1-5 &&
+       verify_parents $c1 $c2
+'
+
+test_debug 'gitk --all'
+
 test_done
diff --git a/t/t7601-merge-pull-config.sh b/t/t7601-merge-pull-config.sh
new file mode 100755
index 0000000000..95b4d71c51
--- /dev/null
+++ b/t/t7601-merge-pull-config.sh
@@ -0,0 +1,129 @@
+#!/bin/sh
+
+test_description='git-merge
+
+Testing pull.* configuration parsing.'
+
+. ./test-lib.sh
+
+test_expect_success 'setup' '
+	echo c0 >c0.c &&
+	git add c0.c &&
+	git commit -m c0 &&
+	git tag c0 &&
+	echo c1 >c1.c &&
+	git add c1.c &&
+	git commit -m c1 &&
+	git tag c1 &&
+	git reset --hard c0 &&
+	echo c2 >c2.c &&
+	git add c2.c &&
+	git commit -m c2 &&
+	git tag c2 &&
+	git reset --hard c0 &&
+	echo c3 >c3.c &&
+	git add c3.c &&
+	git commit -m c3 &&
+	git tag c3
+'
+
+test_expect_success 'merge c1 with c2' '
+	git reset --hard c1 &&
+	test -f c0.c &&
+	test -f c1.c &&
+	test ! -f c2.c &&
+	test ! -f c3.c &&
+	git merge c2 &&
+	test -f c1.c &&
+	test -f c2.c
+'
+
+test_expect_success 'merge c1 with c2 (ours in pull.twohead)' '
+	git reset --hard c1 &&
+	git config pull.twohead ours &&
+	git merge c2 &&
+	test -f c1.c &&
+	! test -f c2.c
+'
+
+test_expect_success 'merge c1 with c2 and c3 (recursive in pull.octopus)' '
+	git reset --hard c1 &&
+	git config pull.octopus "recursive" &&
+	test_must_fail git merge c2 c3 &&
+	test "$(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)" = "$(git rev-parse HEAD^3)" &&
+	git diff --exit-code &&
+	test -f c0.c &&
+	test -f c1.c &&
+	test -f c2.c &&
+	test -f c3.c
+'
+
+conflict_count()
+{
+	{
+		git diff-files --name-only
+		git ls-files --unmerged
+	} | wc -l
+}
+
+# c4 - c5
+#    \ c6
+#
+# There are two conflicts here:
+#
+# 1) Because foo.c is renamed to bar.c, recursive will handle this,
+# resolve won't.
+#
+# 2) One in conflict.c and that will always fail.
+
+test_expect_success 'setup conflicted merge' '
+	git reset --hard c0 &&
+	echo A >conflict.c &&
+	git add conflict.c &&
+	echo contents >foo.c &&
+	git add foo.c &&
+	git commit -m c4 &&
+	git tag c4 &&
+	echo B >conflict.c &&
+	git add conflict.c &&
+	git mv foo.c bar.c &&
+	git commit -m c5 &&
+	git tag c5 &&
+	git reset --hard c4 &&
+	echo C >conflict.c &&
+	git add conflict.c &&
+	echo secondline >> foo.c &&
+	git add foo.c &&
+	git commit -m c6 &&
+	git tag c6
+'
+
+# First do the merge with resolve and recursive then verify that
+# recusive is choosen.
+
+test_expect_success 'merge picks up the best result' '
+	git config pull.twohead "recursive resolve" &&
+	git reset --hard c5 &&
+	git merge -s resolve c6
+	resolve_count=$(conflict_count) &&
+	git reset --hard c5 &&
+	git merge -s recursive c6
+	recursive_count=$(conflict_count) &&
+	git reset --hard c5 &&
+	git merge c6
+	auto_count=$(conflict_count) &&
+	test $auto_count = $recursive_count &&
+	test $auto_count != $resolve_count
+'
+
+test_done
diff --git a/t/t7602-merge-octopus-many.sh b/t/t7602-merge-octopus-many.sh
new file mode 100755
index 0000000000..fcb8285746
--- /dev/null
+++ b/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_success '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 $i + 1` || return 1
+	done
+'
+
+test_done
diff --git a/t/t7603-merge-reduce-heads.sh b/t/t7603-merge-reduce-heads.sh
new file mode 100755
index 0000000000..17b19dc11f
--- /dev/null
+++ b/t/t7603-merge-reduce-heads.sh
@@ -0,0 +1,63 @@
+#!/bin/sh
+
+test_description='git-merge
+
+Testing octopus merge when reducing parents to independent branches.'
+
+. ./test-lib.sh
+
+# 0 - 1
+#   \ 2
+#   \ 3
+#   \ 4 - 5
+#
+# So 1, 2, 3 and 5 should be kept, 4 should be avoided.
+
+test_expect_success 'setup' '
+	echo c0 > c0.c &&
+	git add c0.c &&
+	git commit -m c0 &&
+	git tag c0 &&
+	echo c1 > c1.c &&
+	git add c1.c &&
+	git commit -m c1 &&
+	git tag c1 &&
+	git reset --hard c0 &&
+	echo c2 > c2.c &&
+	git add c2.c &&
+	git commit -m c2 &&
+	git tag c2 &&
+	git reset --hard c0 &&
+	echo c3 > c3.c &&
+	git add c3.c &&
+	git commit -m c3 &&
+	git tag c3 &&
+	git reset --hard c0 &&
+	echo c4 > c4.c &&
+	git add c4.c &&
+	git commit -m c4 &&
+	git tag c4 &&
+	echo c5 > c5.c &&
+	git add c5.c &&
+	git commit -m c5 &&
+	git tag c5
+'
+
+test_expect_success 'merge c1 with c2, c3, c4, c5' '
+	git reset --hard c1 &&
+	git merge c2 c3 c4 c5 &&
+	test "$(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)" = "$(git rev-parse HEAD^3)" &&
+	test "$(git rev-parse c5)" = "$(git rev-parse HEAD^4)" &&
+	git diff --exit-code &&
+	test -f c0.c &&
+	test -f c1.c &&
+	test -f c2.c &&
+	test -f c3.c &&
+	test -f c4.c &&
+	test -f c5.c
+'
+
+test_done
diff --git a/t/t7604-merge-custom-message.sh b/t/t7604-merge-custom-message.sh
new file mode 100755
index 0000000000..6081677d23
--- /dev/null
+++ b/t/t7604-merge-custom-message.sh
@@ -0,0 +1,37 @@
+#!/bin/sh
+
+test_description='git-merge
+
+Testing merge when using a custom message for the merge commit.'
+
+. ./test-lib.sh
+
+test_expect_success 'setup' '
+	echo c0 > c0.c &&
+	git add c0.c &&
+	git commit -m c0 &&
+	git tag c0 &&
+	echo c1 > c1.c &&
+	git add c1.c &&
+	git commit -m c1 &&
+	git tag c1 &&
+	git reset --hard c0 &&
+	echo c2 > c2.c &&
+	git add c2.c &&
+	git commit -m c2 &&
+	git tag c2
+'
+
+cat >expected <<\EOF
+custom message
+
+Merge commit 'c2'
+EOF
+test_expect_success 'merge c2 with a custom message' '
+	git reset --hard c1 &&
+	git merge -m "custom message" c2 &&
+	git cat-file commit HEAD | sed -e "1,/^$/d" > actual &&
+	test_cmp expected actual
+'
+
+test_done
diff --git a/t/t7605-merge-resolve.sh b/t/t7605-merge-resolve.sh
new file mode 100755
index 0000000000..ee21a107fd
--- /dev/null
+++ b/t/t7605-merge-resolve.sh
@@ -0,0 +1,46 @@
+#!/bin/sh
+
+test_description='git-merge
+
+Testing the resolve strategy.'
+
+. ./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 > c2.c &&
+	git add c2.c &&
+	git commit -m c3 &&
+	git tag c3
+'
+
+test_expect_success 'merge c1 to c2' '
+	git reset --hard c1 &&
+	git merge -s resolve c2 &&
+	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)" &&
+	git diff --exit-code &&
+	test -f c0.c &&
+	test -f c1.c &&
+	test -f c2.c
+'
+
+test_expect_success 'merge c2 to c3 (fails)' '
+	git reset --hard c2 &&
+	test_must_fail git merge -s resolve c3
+'
+test_done