Merge branch 'ds/revision-maximal-only'

"git rev-list" and friends learn "--maximal-only" to show only the
commits that are not reachable by other commits.

* ds/revision-maximal-only:
  revision: add --maximal-only option

2 files changed, 90 insertions, 0 deletions

diff --git a/t/t6000-rev-list-misc.sh b/t/t6000-rev-list-misc.sh
index fec16448cf..d0a2a86610 100755
--- a/t/t6000-rev-list-misc.sh
+++ b/t/t6000-rev-list-misc.sh
@@ -248,4 +248,19 @@ test_expect_success 'rev-list -z --boundary' '
 	test_cmp expect actual
 '
 
+test_expect_success 'rev-list --boundary incompatible with --maximal-only' '
+	test_when_finished rm -rf repo &&
+
+	git init repo &&
+	test_commit -C repo 1 &&
+	test_commit -C repo 2 &&
+
+	oid1=$(git -C repo rev-parse HEAD~) &&
+	oid2=$(git -C repo rev-parse HEAD) &&
+
+	test_must_fail git -C repo rev-list --boundary --maximal-only \
+		HEAD~1..HEAD 2>err &&
+	test_grep "cannot be used together" err
+'
+
 test_done
diff --git a/t/t6600-test-reach.sh b/t/t6600-test-reach.sh
index 6638d1aa1d..2613075894 100755
--- a/t/t6600-test-reach.sh
+++ b/t/t6600-test-reach.sh
@@ -762,4 +762,79 @@ test_expect_success 'for-each-ref is-base: --sort' '
 		--sort=refname --sort=-is-base:commit-2-3
 '
 
+test_expect_success 'rev-list --maximal-only (all positive)' '
+	# Only one maximal.
+	cat >input <<-\EOF &&
+	refs/heads/commit-1-1
+	refs/heads/commit-4-2
+	refs/heads/commit-4-4
+	refs/heads/commit-8-4
+	EOF
+
+	cat >expect <<-EOF &&
+	$(git rev-parse refs/heads/commit-8-4)
+	EOF
+	run_all_modes git rev-list --maximal-only --stdin &&
+
+	# All maximal.
+	cat >input <<-\EOF &&
+	refs/heads/commit-5-2
+	refs/heads/commit-4-3
+	refs/heads/commit-3-4
+	refs/heads/commit-2-5
+	EOF
+
+	cat >expect <<-EOF &&
+	$(git rev-parse refs/heads/commit-5-2)
+	$(git rev-parse refs/heads/commit-4-3)
+	$(git rev-parse refs/heads/commit-3-4)
+	$(git rev-parse refs/heads/commit-2-5)
+	EOF
+	run_all_modes git rev-list --maximal-only --stdin &&
+
+	# Mix of both.
+	cat >input <<-\EOF &&
+	refs/heads/commit-5-2
+	refs/heads/commit-3-2
+	refs/heads/commit-2-5
+	EOF
+
+	cat >expect <<-EOF &&
+	$(git rev-parse refs/heads/commit-5-2)
+	$(git rev-parse refs/heads/commit-2-5)
+	EOF
+	run_all_modes git rev-list --maximal-only --stdin
+'
+
+test_expect_success 'rev-list --maximal-only (range)' '
+	cat >input <<-\EOF &&
+	refs/heads/commit-1-1
+	refs/heads/commit-2-5
+	refs/heads/commit-6-4
+	^refs/heads/commit-4-5
+	EOF
+
+	cat >expect <<-EOF &&
+	$(git rev-parse refs/heads/commit-6-4)
+	EOF
+	run_all_modes git rev-list --maximal-only --stdin &&
+
+	# first-parent changes reachability: the first parent
+	# reduces the second coordinate to 1 before reducing the
+	# first coordinate.
+	cat >input <<-\EOF &&
+	refs/heads/commit-1-1
+	refs/heads/commit-2-5
+	refs/heads/commit-6-4
+	^refs/heads/commit-4-5
+	EOF
+
+	cat >expect <<-EOF &&
+	$(git rev-parse refs/heads/commit-6-4)
+	$(git rev-parse refs/heads/commit-2-5)
+	EOF
+	run_all_modes git rev-list --maximal-only --stdin \
+		--first-parent --exclude-first-parent-only
+'
+
 test_done