Collect merge-related tests to t64xx

The tests for the merge machinery are spread over several places.
Collect them into t64xx for simplicity.  Some notes:

t60[234]*.sh:
  Merge tests started in t602*, overgrew bisect and remote tracking
  tests in t6030, t6040, and t6041, and nearly overtook replace tests
  in t6050.  This made picking out relevant tests that I wanted to run
  in a tighter loop slightly more annoying for years.

t303*.sh:
  These started out as tests for the 'merge-recursive' toplevel command,
  but did not restrict to that and had lots of overlap with the
  underlying merge machinery.
t7405, t7613:
  submodule-specific merge logic started out in submodule.c but was
  moved to merge-recursive.c in commit 18cfc08866 ("submodule.c: move
  submodule merging to merge-recursive.c", 2018-05-15).  Since these
  tests are about the logic found in the merge machinery, moving these
  tests to be with the merge tests makes sense.

t7607, t7609:
  Having tests spread all over the place makes it more likely that
  additional tests related to a certain piece of logic grow in all those
  other places.  Much like t303*.sh, these two tests were about the
  underlying merge machinery rather than outer levels.

Tests that were NOT moved:

t76[01]*.sh:
  Other than the four tests mentioned above, the remaining tests in
  t76[01]*.sh are related to non-recursive merge strategies, parameter
  parsing, and other stuff associated with the highlevel builtin/merge.c
  rather than the recursive merge machinery.

t3[45]*.sh:
  The rebase testcases in t34*.sh also test the merge logic pretty
  heavily; sometimes changes I make only trigger failures in the rebase
  tests.  The rebase tests are already nicely coupled together, though,
  and I didn't want to mess that up.  Similar comments apply for the
  cherry-pick tests in t35*.sh.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 174 insertions, 0 deletions

diff --git a/t/t6433-merge-toplevel.sh b/t/t6433-merge-toplevel.sh
new file mode 100755
index 0000000000..e29c284b9b
--- /dev/null
+++ b/t/t6433-merge-toplevel.sh
@@ -0,0 +1,174 @@
+#!/bin/sh
+
+test_description='"git merge" top-level frontend'
+
+. ./test-lib.sh
+
+t3033_reset () {
+	git checkout -B master two &&
+	git branch -f left three &&
+	git branch -f right four
+}
+
+test_expect_success setup '
+	test_commit one &&
+	git branch left &&
+	git branch right &&
+	test_commit two &&
+	git checkout left &&
+	test_commit three &&
+	git checkout right &&
+	test_commit four &&
+	git checkout --orphan newroot &&
+	test_commit five &&
+	git checkout master
+'
+
+# Local branches
+
+test_expect_success 'merge an octopus into void' '
+	t3033_reset &&
+	git checkout --orphan test &&
+	git rm -fr . &&
+	test_must_fail git merge left right &&
+	test_must_fail git rev-parse --verify HEAD &&
+	git diff --quiet &&
+	test_must_fail git rev-parse HEAD
+'
+
+test_expect_success 'merge an octopus, fast-forward (ff)' '
+	t3033_reset &&
+	git reset --hard one &&
+	git merge left right &&
+	# one is ancestor of three (left) and four (right)
+	test_must_fail git rev-parse --verify HEAD^3 &&
+	git rev-parse HEAD^1 HEAD^2 | sort >actual &&
+	git rev-parse three four | sort >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'merge octopus, non-fast-forward (ff)' '
+	t3033_reset &&
+	git reset --hard one &&
+	git merge --no-ff left right &&
+	# one is ancestor of three (left) and four (right)
+	test_must_fail git rev-parse --verify HEAD^4 &&
+	git rev-parse HEAD^1 HEAD^2 HEAD^3 | sort >actual &&
+	git rev-parse one three four | sort >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'merge octopus, fast-forward (does not ff)' '
+	t3033_reset &&
+	git merge left right &&
+	# two (master) is not an ancestor of three (left) and four (right)
+	test_must_fail git rev-parse --verify HEAD^4 &&
+	git rev-parse HEAD^1 HEAD^2 HEAD^3 | sort >actual &&
+	git rev-parse two three four | sort >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'merge octopus, non-fast-forward' '
+	t3033_reset &&
+	git merge --no-ff left right &&
+	test_must_fail git rev-parse --verify HEAD^4 &&
+	git rev-parse HEAD^1 HEAD^2 HEAD^3 | sort >actual &&
+	git rev-parse two three four | sort >expect &&
+	test_cmp expect actual
+'
+
+# The same set with FETCH_HEAD
+
+test_expect_success 'merge FETCH_HEAD octopus into void' '
+	t3033_reset &&
+	git checkout --orphan test &&
+	git rm -fr . &&
+	git fetch . left right &&
+	test_must_fail git merge FETCH_HEAD &&
+	test_must_fail git rev-parse --verify HEAD &&
+	git diff --quiet &&
+	test_must_fail git rev-parse HEAD
+'
+
+test_expect_success 'merge FETCH_HEAD octopus fast-forward (ff)' '
+	t3033_reset &&
+	git reset --hard one &&
+	git fetch . left right &&
+	git merge FETCH_HEAD &&
+	# one is ancestor of three (left) and four (right)
+	test_must_fail git rev-parse --verify HEAD^3 &&
+	git rev-parse HEAD^1 HEAD^2 | sort >actual &&
+	git rev-parse three four | sort >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'merge FETCH_HEAD octopus non-fast-forward (ff)' '
+	t3033_reset &&
+	git reset --hard one &&
+	git fetch . left right &&
+	git merge --no-ff FETCH_HEAD &&
+	# one is ancestor of three (left) and four (right)
+	test_must_fail git rev-parse --verify HEAD^4 &&
+	git rev-parse HEAD^1 HEAD^2 HEAD^3 | sort >actual &&
+	git rev-parse one three four | sort >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'merge FETCH_HEAD octopus fast-forward (does not ff)' '
+	t3033_reset &&
+	git fetch . left right &&
+	git merge FETCH_HEAD &&
+	# two (master) is not an ancestor of three (left) and four (right)
+	test_must_fail git rev-parse --verify HEAD^4 &&
+	git rev-parse HEAD^1 HEAD^2 HEAD^3 | sort >actual &&
+	git rev-parse two three four | sort >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'merge FETCH_HEAD octopus non-fast-forward' '
+	t3033_reset &&
+	git fetch . left right &&
+	git merge --no-ff FETCH_HEAD &&
+	test_must_fail git rev-parse --verify HEAD^4 &&
+	git rev-parse HEAD^1 HEAD^2 HEAD^3 | sort >actual &&
+	git rev-parse two three four | sort >expect &&
+	test_cmp expect actual
+'
+
+# two-project merge
+test_expect_success 'refuse two-project merge by default' '
+	t3033_reset &&
+	git reset --hard four &&
+	test_must_fail git merge five
+'
+
+test_expect_success 'refuse two-project merge by default, quit before --autostash happens' '
+	t3033_reset &&
+	git reset --hard four &&
+	echo change >>one.t &&
+	git diff >expect &&
+	test_must_fail git merge --autostash five 2>err &&
+	test_i18ngrep ! "stash" err &&
+	git diff >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'two-project merge with --allow-unrelated-histories' '
+	t3033_reset &&
+	git reset --hard four &&
+	git merge --allow-unrelated-histories five &&
+	git diff --exit-code five
+'
+
+test_expect_success 'two-project merge with --allow-unrelated-histories with --autostash' '
+	t3033_reset &&
+	git reset --hard four &&
+	echo change >>one.t &&
+	git diff one.t >expect &&
+	git merge --allow-unrelated-histories --autostash five 2>err &&
+	test_i18ngrep "Applied autostash." err &&
+	git diff one.t >actual &&
+	test_cmp expect actual
+'
+
+test_done