3 files changed, 234 insertions, 0 deletions
diff --git a/t/meson.build b/t/meson.build
index baeeba2ce6..82af229be3 100644
--- a/t/meson.build
+++ b/t/meson.build
@@ -951,6 +951,7 @@ integration_tests = [
   't8012-blame-colors.sh',
   't8013-blame-ignore-revs.sh',
   't8014-blame-ignore-fuzzy.sh',
+  't8020-last-modified.sh',
   't9001-send-email.sh',
   't9002-column.sh',
   't9003-help-autocorrect.sh',
@@ -1144,6 +1145,7 @@ benchmarks = [
   'perf/p7820-grep-engines.sh',
   'perf/p7821-grep-engines-fixed.sh',
   'perf/p7822-grep-perl-character.sh',
+  'perf/p8020-last-modified.sh',
   'perf/p9210-scalar.sh',
   'perf/p9300-fast-import-export.sh',
 ]
diff --git a/t/perf/p8020-last-modified.sh b/t/perf/p8020-last-modified.sh
new file mode 100755
index 0000000000..cb1f98d3db
--- /dev/null
+++ b/t/perf/p8020-last-modified.sh
@@ -0,0 +1,22 @@
+#!/bin/sh
+
+test_description='last-modified perf tests'
+. ./perf-lib.sh
+
+test_perf_default_repo
+
+test_perf 'top-level last-modified' '
+	git last-modified HEAD
+'
+
+test_perf 'top-level recursive last-modified' '
+	git last-modified -r HEAD
+'
+
+test_perf 'subdir last-modified' '
+	git ls-tree -d HEAD >subtrees &&
+	path="$(head -n 1 subtrees | cut -f2)" &&
+	git last-modified -r HEAD -- "$path"
+'
+
+test_done
diff --git a/t/t8020-last-modified.sh b/t/t8020-last-modified.sh
new file mode 100755
index 0000000000..5eb4cef035
--- /dev/null
+++ b/t/t8020-last-modified.sh
@@ -0,0 +1,210 @@
+#!/bin/sh
+
+test_description='last-modified tests'
+
+. ./test-lib.sh
+
+test_expect_success 'setup' '
+	test_commit 1 file &&
+	mkdir a &&
+	test_commit 2 a/file &&
+	mkdir a/b &&
+	test_commit 3 a/b/file
+'
+
+test_expect_success 'cannot run last-modified on two trees' '
+	test_must_fail git last-modified HEAD HEAD~1
+'
+
+check_last_modified() {
+	local indir= &&
+	while test $# != 0
+	do
+		case "$1" in
+		-C)
+			indir="$2"
+			shift
+			;;
+		*)
+			break
+			;;
+		esac &&
+		shift
+	done &&
+
+	cat >expect &&
+	test_when_finished "rm -f tmp.*" &&
+	git ${indir:+-C "$indir"} last-modified "$@" >tmp.1 &&
+	git name-rev --annotate-stdin --name-only --tags \
+		<tmp.1 >tmp.2 &&
+	tr '\t' ' ' <tmp.2 >actual &&
+	test_cmp expect actual
+}
+
+test_expect_success 'last-modified non-recursive' '
+	check_last_modified <<-\EOF
+	3 a
+	1 file
+	EOF
+'
+
+test_expect_success 'last-modified recursive' '
+	check_last_modified -r <<-\EOF
+	3 a/b/file
+	2 a/file
+	1 file
+	EOF
+'
+
+test_expect_success 'last-modified recursive with show-trees' '
+	check_last_modified -r -t <<-\EOF
+	3 a
+	3 a/b
+	3 a/b/file
+	2 a/file
+	1 file
+	EOF
+'
+
+test_expect_success 'last-modified non-recursive with show-trees' '
+	check_last_modified -t <<-\EOF
+	3 a
+	1 file
+	EOF
+'
+
+test_expect_success 'last-modified subdir' '
+	check_last_modified a <<-\EOF
+	3 a
+	EOF
+'
+
+test_expect_success 'last-modified subdir recursive' '
+	check_last_modified -r a <<-\EOF
+	3 a/b/file
+	2 a/file
+	EOF
+'
+
+test_expect_success 'last-modified from non-HEAD commit' '
+	check_last_modified HEAD^ <<-\EOF
+	2 a
+	1 file
+	EOF
+'
+
+test_expect_success 'last-modified from subdir defaults to root' '
+	check_last_modified -C a <<-\EOF
+	3 a
+	1 file
+	EOF
+'
+
+test_expect_success 'last-modified from subdir uses relative pathspecs' '
+	check_last_modified -C a -r b <<-\EOF
+	3 a/b/file
+	EOF
+'
+
+test_expect_success 'limit last-modified traversal by count' '
+	check_last_modified -1 <<-\EOF
+	3 a
+	^2 file
+	EOF
+'
+
+test_expect_success 'limit last-modified traversal by commit' '
+	check_last_modified HEAD~2..HEAD <<-\EOF
+	3 a
+	^1 file
+	EOF
+'
+
+test_expect_success 'only last-modified files in the current tree' '
+	git rm -rf a &&
+	git commit -m "remove a" &&
+	check_last_modified <<-\EOF
+	1 file
+	EOF
+'
+
+test_expect_success 'cross merge boundaries in blaming' '
+	git checkout HEAD^0 &&
+	git rm -rf . &&
+	test_commit m1 &&
+	git checkout HEAD^ &&
+	git rm -rf . &&
+	test_commit m2 &&
+	git merge m1 &&
+	check_last_modified <<-\EOF
+	m2 m2.t
+	m1 m1.t
+	EOF
+'
+
+test_expect_success 'last-modified merge for resolved conflicts' '
+	git checkout HEAD^0 &&
+	git rm -rf . &&
+	test_commit c1 conflict &&
+	git checkout HEAD^ &&
+	git rm -rf . &&
+	test_commit c2 conflict &&
+	test_must_fail git merge c1 &&
+	test_commit resolved conflict &&
+	check_last_modified conflict <<-\EOF
+	resolved conflict
+	EOF
+'
+
+
+# Consider `file` with this content through history:
+#
+# A---B---B-------B---B
+#          \     /
+#           C---D
+test_expect_success 'last-modified merge ignores content from branch' '
+	git checkout HEAD^0 &&
+	git rm -rf . &&
+	test_commit a1 file A &&
+	test_commit a2 file B &&
+	test_commit a3 file C &&
+	test_commit a4 file D &&
+	git checkout a2 &&
+	git merge --no-commit --no-ff a4 &&
+	git checkout a2 -- file &&
+	git merge --continue &&
+	check_last_modified <<-\EOF
+	a2 file
+	EOF
+'
+
+# Consider `file` with this content through history:
+#
+#  A---B---B---C---D---B---B
+#           \         /
+#            B-------B
+test_expect_success 'last-modified merge undoes changes' '
+	git checkout HEAD^0 &&
+	git rm -rf . &&
+	test_commit b1 file A &&
+	test_commit b2 file B &&
+	test_commit b3 file C &&
+	test_commit b4 file D &&
+	git checkout b2 &&
+	test_commit b5 file2 2 &&
+	git checkout b4 &&
+	git merge --no-commit --no-ff b5 &&
+	git checkout b2 -- file &&
+	git merge --continue &&
+	check_last_modified <<-\EOF
+	b5 file2
+	b2 file
+	EOF
+'
+
+test_expect_success 'last-modified complains about unknown arguments' '
+	test_must_fail git last-modified --foo 2>err &&
+	grep "unknown last-modified argument: --foo" err
+'
+
+test_done