Adding upstream version 1:2.39.2.upstream/1%2.39.2upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1468 insertions, 0 deletions

diff --git a/t/t6422-merge-rename-corner-cases.sh b/t/t6422-merge-rename-corner-cases.sh
new file mode 100755
index 0000000..346253c
--- /dev/null
+++ b/t/t6422-merge-rename-corner-cases.sh
@@ -0,0 +1,1468 @@
+#!/bin/sh
+
+test_description="recursive merge corner cases w/ renames but not criss-crosses"
+# t6036 has corner cases that involve both criss-cross merges and renames
+
+GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
+export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
+
+TEST_PASSES_SANITIZE_LEAK=true
+. ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-merge.sh
+
+test_setup_rename_delete_untracked () {
+	git init rename-delete-untracked &&
+	(
+		cd rename-delete-untracked &&
+
+		echo "A pretty inscription" >ring &&
+		git add ring &&
+		test_tick &&
+		git commit -m beginning &&
+
+		git branch people &&
+		git checkout -b rename-the-ring &&
+		git mv ring one-ring-to-rule-them-all &&
+		test_tick &&
+		git commit -m fullname &&
+
+		git checkout people &&
+		git rm ring &&
+		echo gollum >owner &&
+		git add owner &&
+		test_tick &&
+		git commit -m track-people-instead-of-objects &&
+		echo "Myyy PRECIOUSSS" >ring
+	)
+}
+
+test_expect_success "Does git preserve Gollum's precious artifact?" '
+	test_setup_rename_delete_untracked &&
+	(
+		cd rename-delete-untracked &&
+
+		test_must_fail git merge -s recursive rename-the-ring &&
+
+		# Make sure git did not delete an untracked file
+		test_path_is_file ring
+	)
+'
+
+# Testcase setup for rename/modify/add-source:
+#   Commit A: new file: a
+#   Commit B: modify a slightly
+#   Commit C: rename a->b, add completely different a
+#
+# We should be able to merge B & C cleanly
+
+test_setup_rename_modify_add_source () {
+	git init rename-modify-add-source &&
+	(
+		cd rename-modify-add-source &&
+
+		printf "1\n2\n3\n4\n5\n6\n7\n" >a &&
+		git add a &&
+		git commit -m A &&
+		git tag A &&
+
+		git checkout -b B A &&
+		echo 8 >>a &&
+		git add a &&
+		git commit -m B &&
+
+		git checkout -b C A &&
+		git mv a b &&
+		echo something completely different >a &&
+		git add a &&
+		git commit -m C
+	)
+}
+
+test_expect_failure 'rename/modify/add-source conflict resolvable' '
+	test_setup_rename_modify_add_source &&
+	(
+		cd rename-modify-add-source &&
+
+		git checkout B^0 &&
+
+		git merge -s recursive C^0 &&
+
+		git rev-parse >expect \
+			B:a   C:a     &&
+		git rev-parse >actual \
+			b     c       &&
+		test_cmp expect actual
+	)
+'
+
+test_setup_break_detection_1 () {
+	git init break-detection-1 &&
+	(
+		cd break-detection-1 &&
+
+		printf "1\n2\n3\n4\n5\n" >a &&
+		echo foo >b &&
+		git add a b &&
+		git commit -m A &&
+		git tag A &&
+
+		git checkout -b B A &&
+		git mv a c &&
+		echo "Completely different content" >a &&
+		git add a &&
+		git commit -m B &&
+
+		git checkout -b C A &&
+		echo 6 >>a &&
+		git add a &&
+		git commit -m C
+	)
+}
+
+test_expect_failure 'conflict caused if rename not detected' '
+	test_setup_break_detection_1 &&
+	(
+		cd break-detection-1 &&
+
+		git checkout -q C^0 &&
+		git merge -s recursive B^0 &&
+
+		git ls-files -s >out &&
+		test_line_count = 3 out &&
+		git ls-files -u >out &&
+		test_line_count = 0 out &&
+		git ls-files -o >out &&
+		test_line_count = 1 out &&
+
+		test_line_count = 6 c &&
+		git rev-parse >expect \
+			B:a   A:b     &&
+		git rev-parse >actual \
+			:0:a  :0:b    &&
+		test_cmp expect actual
+	)
+'
+
+test_setup_break_detection_2 () {
+	git init break-detection-2 &&
+	(
+		cd break-detection-2 &&
+
+		printf "1\n2\n3\n4\n5\n" >a &&
+		echo foo >b &&
+		git add a b &&
+		git commit -m A &&
+		git tag A &&
+
+		git checkout -b D A &&
+		echo 7 >>a &&
+		git add a &&
+		git mv a c &&
+		echo "Completely different content" >a &&
+		git add a &&
+		git commit -m D &&
+
+		git checkout -b E A &&
+		git rm a &&
+		echo "Completely different content" >>a &&
+		git add a &&
+		git commit -m E
+	)
+}
+
+test_expect_failure 'missed conflict if rename not detected' '
+	test_setup_break_detection_2 &&
+	(
+		cd break-detection-2 &&
+
+		git checkout -q E^0 &&
+		test_must_fail git merge -s recursive D^0
+	)
+'
+
+# Tests for undetected rename/add-source causing a file to erroneously be
+# deleted (and for mishandled rename/rename(1to1) causing the same issue).
+#
+# This test uses a rename/rename(1to1)+add-source conflict (1to1 means the
+# same file is renamed on both sides to the same thing; it should trigger
+# the 1to2 logic, which it would do if the add-source didn't cause issues
+# for git's rename detection):
+#   Commit A: new file: a
+#   Commit B: rename a->b
+#   Commit C: rename a->b, add unrelated a
+
+test_setup_break_detection_3 () {
+	git init break-detection-3 &&
+	(
+		cd break-detection-3 &&
+
+		printf "1\n2\n3\n4\n5\n" >a &&
+		git add a &&
+		git commit -m A &&
+		git tag A &&
+
+		git checkout -b B A &&
+		git mv a b &&
+		git commit -m B &&
+
+		git checkout -b C A &&
+		git mv a b &&
+		echo foobar >a &&
+		git add a &&
+		git commit -m C
+	)
+}
+
+test_expect_failure 'detect rename/add-source and preserve all data' '
+	test_setup_break_detection_3 &&
+	(
+		cd break-detection-3 &&
+
+		git checkout B^0 &&
+
+		git merge -s recursive C^0 &&
+
+		git ls-files -s >out &&
+		test_line_count = 2 out &&
+		git ls-files -u >out &&
+		test_line_count = 2 out &&
+		git ls-files -o >out &&
+		test_line_count = 1 out &&
+
+		test_path_is_file a &&
+		test_path_is_file b &&
+
+		git rev-parse >expect \
+			A:a   C:a     &&
+		git rev-parse >actual \
+			:0:b  :0:a    &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_failure 'detect rename/add-source and preserve all data, merge other way' '
+	test_setup_break_detection_3 &&
+	(
+		cd break-detection-3 &&
+
+		git checkout C^0 &&
+
+		git merge -s recursive B^0 &&
+
+		git ls-files -s >out &&
+		test_line_count = 2 out &&
+		git ls-files -u >out &&
+		test_line_count = 2 out &&
+		git ls-files -o >out &&
+		test_line_count = 1 out &&
+
+		test_path_is_file a &&
+		test_path_is_file b &&
+
+		git rev-parse >expect \
+			A:a   C:a     &&
+		git rev-parse >actual \
+			:0:b  :0:a    &&
+		test_cmp expect actual
+	)
+'
+
+test_setup_rename_directory () {
+	git init rename-directory-$1 &&
+	(
+		cd rename-directory-$1 &&
+
+		printf "1\n2\n3\n4\n5\n6\n" >file &&
+		git add file &&
+		test_tick &&
+		git commit -m base &&
+		git tag base &&
+
+		git checkout -b right &&
+		echo 7 >>file &&
+		mkdir newfile &&
+		echo junk >newfile/realfile &&
+		git add file newfile/realfile &&
+		test_tick &&
+		git commit -m right &&
+
+		git checkout -b left-conflict base &&
+		echo 8 >>file &&
+		git add file &&
+		git mv file newfile &&
+		test_tick &&
+		git commit -m left &&
+
+		git checkout -b left-clean base &&
+		echo 0 >newfile &&
+		cat file >>newfile &&
+		git add newfile &&
+		git rm file &&
+		test_tick &&
+		git commit -m left
+	)
+}
+
+test_expect_success 'rename/directory conflict + clean content merge' '
+	test_setup_rename_directory 1a &&
+	(
+		cd rename-directory-1a &&
+
+		git checkout left-clean^0 &&
+
+		test_must_fail git merge -s recursive right^0 &&
+
+		git ls-files -s >out &&
+		test_line_count = 2 out &&
+		git ls-files -u >out &&
+		test_line_count = 1 out &&
+		git ls-files -o >out &&
+		if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+		then
+			test_line_count = 1 out
+		else
+			test_line_count = 2 out
+		fi &&
+
+		echo 0 >expect &&
+		git cat-file -p base:file >>expect &&
+		echo 7 >>expect &&
+		test_cmp expect newfile~HEAD &&
+
+		test_path_is_file newfile/realfile &&
+		test_path_is_file newfile~HEAD
+	)
+'
+
+test_expect_success 'rename/directory conflict + content merge conflict' '
+	test_setup_rename_directory 1b &&
+	(
+		cd rename-directory-1b &&
+
+		git reset --hard &&
+		git clean -fdqx &&
+
+		git checkout left-conflict^0 &&
+
+		test_must_fail git merge -s recursive right^0 &&
+
+		git ls-files -s >out &&
+		test_line_count = 4 out &&
+		git ls-files -u >out &&
+		test_line_count = 3 out &&
+		git ls-files -o >out &&
+		if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+		then
+			test_line_count = 1 out
+		else
+			test_line_count = 2 out
+		fi &&
+
+		git cat-file -p left-conflict:newfile >left &&
+		git cat-file -p base:file    >base &&
+		git cat-file -p right:file   >right &&
+		test_must_fail git merge-file \
+			-L "HEAD:newfile" \
+			-L "" \
+			-L "right^0:file" \
+			left base right &&
+		test_cmp left newfile~HEAD &&
+
+		git rev-parse >expect   \
+			base:file       left-conflict:newfile right:file &&
+		if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+		then
+			git rev-parse >actual \
+				:1:newfile~HEAD :2:newfile~HEAD :3:newfile~HEAD
+		else
+			git rev-parse >actual \
+				:1:newfile      :2:newfile      :3:newfile
+		fi &&
+		test_cmp expect actual &&
+
+		test_path_is_file newfile/realfile &&
+		test_path_is_file newfile~HEAD
+	)
+'
+
+test_setup_rename_directory_2 () {
+	git init rename-directory-2 &&
+	(
+		cd rename-directory-2 &&
+
+		mkdir sub &&
+		printf "1\n2\n3\n4\n5\n6\n" >sub/file &&
+		git add sub/file &&
+		test_tick &&
+		git commit -m base &&
+		git tag base &&
+
+		git checkout -b right &&
+		echo 7 >>sub/file &&
+		git add sub/file &&
+		test_tick &&
+		git commit -m right &&
+
+		git checkout -b left base &&
+		echo 0 >newfile &&
+		cat sub/file >>newfile &&
+		git rm sub/file &&
+		mv newfile sub &&
+		git add sub &&
+		test_tick &&
+		git commit -m left
+	)
+}
+
+test_expect_success 'disappearing dir in rename/directory conflict handled' '
+	test_setup_rename_directory_2 &&
+	(
+		cd rename-directory-2 &&
+
+		git checkout left^0 &&
+
+		git merge -s recursive right^0 &&
+
+		git ls-files -s >out &&
+		test_line_count = 1 out &&
+		git ls-files -u >out &&
+		test_line_count = 0 out &&
+		git ls-files -o >out &&
+		test_line_count = 1 out &&
+
+		echo 0 >expect &&
+		git cat-file -p base:sub/file >>expect &&
+		echo 7 >>expect &&
+		test_cmp expect sub &&
+
+		test_path_is_file sub
+	)
+'
+
+# Test for basic rename/add-dest conflict, with rename needing content merge:
+#   Commit O: a
+#   Commit A: rename a->b, modifying b too
+#   Commit B: modify a, add different b
+
+test_setup_rename_with_content_merge_and_add () {
+	git init rename-with-content-merge-and-add-$1 &&
+	(
+		cd rename-with-content-merge-and-add-$1 &&
+
+		test_seq 1 5 >a &&
+		git add a &&
+		git commit -m O &&
+		git tag O &&
+
+		git checkout -b A O &&
+		git mv a b &&
+		test_seq 0 5 >b &&
+		git add b &&
+		git commit -m A &&
+
+		git checkout -b B O &&
+		echo 6 >>a &&
+		echo hello world >b &&
+		git add a b &&
+		git commit -m B
+	)
+}
+
+test_expect_success 'handle rename-with-content-merge vs. add' '
+	test_setup_rename_with_content_merge_and_add AB &&
+	(
+		cd rename-with-content-merge-and-add-AB &&
+
+		git checkout A^0 &&
+
+		test_must_fail git merge -s recursive B^0 >out &&
+		test_i18ngrep "CONFLICT (.*/add)" out &&
+
+		git ls-files -s >out &&
+		test_line_count = 2 out &&
+		git ls-files -u >out &&
+		test_line_count = 2 out &&
+		# Also, make sure both unmerged entries are for "b"
+		git ls-files -u b >out &&
+		test_line_count = 2 out &&
+		git ls-files -o >out &&
+		test_line_count = 1 out &&
+
+		test_path_is_missing a &&
+		test_path_is_file b &&
+
+		test_seq 0 6 >tmp &&
+		git hash-object tmp >expect &&
+		git rev-parse B:b >>expect &&
+		git rev-parse >actual  \
+			:2:b    :3:b   &&
+		test_cmp expect actual &&
+
+		# Test that the two-way merge in b is as expected
+		git cat-file -p :2:b >>ours &&
+		git cat-file -p :3:b >>theirs &&
+		>empty &&
+		test_must_fail git merge-file \
+			-L "HEAD" \
+			-L "" \
+			-L "B^0" \
+			ours empty theirs &&
+		test_cmp ours b
+	)
+'
+
+test_expect_success 'handle rename-with-content-merge vs. add, merge other way' '
+	test_setup_rename_with_content_merge_and_add BA &&
+	(
+		cd rename-with-content-merge-and-add-BA &&
+
+		git reset --hard &&
+		git clean -fdx &&
+
+		git checkout B^0 &&
+
+		test_must_fail git merge -s recursive A^0 >out &&
+		test_i18ngrep "CONFLICT (.*/add)" out &&
+
+		git ls-files -s >out &&
+		test_line_count = 2 out &&
+		git ls-files -u >out &&
+		test_line_count = 2 out &&
+		# Also, make sure both unmerged entries are for "b"
+		git ls-files -u b >out &&
+		test_line_count = 2 out &&
+		git ls-files -o >out &&
+		test_line_count = 1 out &&
+
+		test_path_is_missing a &&
+		test_path_is_file b &&
+
+		test_seq 0 6 >tmp &&
+		git rev-parse B:b >expect &&
+		git hash-object tmp >>expect &&
+		git rev-parse >actual  \
+			:2:b    :3:b   &&
+		test_cmp expect actual &&
+
+		# Test that the two-way merge in b is as expected
+		git cat-file -p :2:b >>ours &&
+		git cat-file -p :3:b >>theirs &&
+		>empty &&
+		test_must_fail git merge-file \
+			-L "HEAD" \
+			-L "" \
+			-L "A^0" \
+			ours empty theirs &&
+		test_cmp ours b
+	)
+'
+
+# Test for all kinds of things that can go wrong with rename/rename (2to1):
+#   Commit A: new files: a & b
+#   Commit B: rename a->c, modify b
+#   Commit C: rename b->c, modify a
+#
+# Merging of B & C should NOT be clean.  Questions:
+#   * Both a & b should be removed by the merge; are they?
+#   * The two c's should contain modifications to a & b; do they?
+#   * The index should contain two files, both for c; does it?
+#   * The working copy should have two files, both of form c~<unique>; does it?
+#   * Nothing else should be present.  Is anything?
+
+test_setup_rename_rename_2to1 () {
+	git init rename-rename-2to1 &&
+	(
+		cd rename-rename-2to1 &&
+
+		printf "1\n2\n3\n4\n5\n" >a &&
+		printf "5\n4\n3\n2\n1\n" >b &&
+		git add a b &&
+		git commit -m A &&
+		git tag A &&
+
+		git checkout -b B A &&
+		git mv a c &&
+		echo 0 >>b &&
+		git add b &&
+		git commit -m B &&
+
+		git checkout -b C A &&
+		git mv b c &&
+		echo 6 >>a &&
+		git add a &&
+		git commit -m C
+	)
+}
+
+test_expect_success 'handle rename/rename (2to1) conflict correctly' '
+	test_setup_rename_rename_2to1 &&
+	(
+		cd rename-rename-2to1 &&
+
+		git checkout B^0 &&
+
+		test_must_fail git merge -s recursive C^0 >out &&
+		test_i18ngrep "CONFLICT (\(.*\)/\1)" out &&
+
+		git ls-files -s >out &&
+		test_line_count = 2 out &&
+		git ls-files -u >out &&
+		test_line_count = 2 out &&
+		git ls-files -u c >out &&
+		test_line_count = 2 out &&
+		git ls-files -o >out &&
+		test_line_count = 1 out &&
+
+		test_path_is_missing a &&
+		test_path_is_missing b &&
+
+		git rev-parse >expect  \
+			C:a     B:b    &&
+		git rev-parse >actual  \
+			:2:c    :3:c   &&
+		test_cmp expect actual &&
+
+		# Test that the two-way merge in new_a is as expected
+		git cat-file -p :2:c >>ours &&
+		git cat-file -p :3:c >>theirs &&
+		>empty &&
+		test_must_fail git merge-file \
+			-L "HEAD" \
+			-L "" \
+			-L "C^0" \
+			ours empty theirs &&
+		git hash-object c >actual &&
+		git hash-object ours >expect &&
+		test_cmp expect actual
+	)
+'
+
+# Testcase setup for simple rename/rename (1to2) conflict:
+#   Commit A: new file: a
+#   Commit B: rename a->b
+#   Commit C: rename a->c
+test_setup_rename_rename_1to2 () {
+	git init rename-rename-1to2 &&
+	(
+		cd rename-rename-1to2 &&
+
+		echo stuff >a &&
+		git add a &&
+		test_tick &&
+		git commit -m A &&
+		git tag A &&
+
+		git checkout -b B A &&
+		git mv a b &&
+		test_tick &&
+		git commit -m B &&
+
+		git checkout -b C A &&
+		git mv a c &&
+		test_tick &&
+		git commit -m C
+	)
+}
+
+test_expect_success 'merge has correct working tree contents' '
+	test_setup_rename_rename_1to2 &&
+	(
+		cd rename-rename-1to2 &&
+
+		git checkout C^0 &&
+
+		test_must_fail git merge -s recursive B^0 &&
+
+		git ls-files -s >out &&
+		test_line_count = 3 out &&
+		git ls-files -u >out &&
+		test_line_count = 3 out &&
+		git ls-files -o >out &&
+		test_line_count = 1 out &&
+
+		test_path_is_missing a &&
+		git rev-parse >expect   \
+			A:a   A:a   A:a \
+			A:a   A:a       &&
+		git rev-parse >actual    \
+			:1:a  :3:b  :2:c &&
+		git hash-object >>actual \
+			b     c          &&
+		test_cmp expect actual
+	)
+'
+
+# Testcase setup for rename/rename(1to2)/add-source conflict:
+#   Commit A: new file: a
+#   Commit B: rename a->b
+#   Commit C: rename a->c, add completely different a
+#
+# Merging of B & C should NOT be clean; there's a rename/rename conflict
+
+test_setup_rename_rename_1to2_add_source_1 () {
+	git init rename-rename-1to2-add-source-1 &&
+	(
+		cd rename-rename-1to2-add-source-1 &&
+
+		printf "1\n2\n3\n4\n5\n6\n7\n" >a &&
+		git add a &&
+		git commit -m A &&
+		git tag A &&
+
+		git checkout -b B A &&
+		git mv a b &&
+		git commit -m B &&
+
+		git checkout -b C A &&
+		git mv a c &&
+		echo something completely different >a &&
+		git add a &&
+		git commit -m C
+	)
+}
+
+test_expect_failure 'detect conflict with rename/rename(1to2)/add-source merge' '
+	test_setup_rename_rename_1to2_add_source_1 &&
+	(
+		cd rename-rename-1to2-add-source-1 &&
+
+		git checkout B^0 &&
+
+		test_must_fail git merge -s recursive C^0 &&
+
+		git ls-files -s >out &&
+		test_line_count = 4 out &&
+		git ls-files -o >out &&
+		test_line_count = 1 out &&
+
+		git rev-parse >expect         \
+			C:a   A:a   B:b   C:C &&
+		git rev-parse >actual          \
+			:3:a  :1:a  :2:b  :3:c &&
+		test_cmp expect actual &&
+
+		test_path_is_file a &&
+		test_path_is_file b &&
+		test_path_is_file c
+	)
+'
+
+test_setup_rename_rename_1to2_add_source_2 () {
+	git init rename-rename-1to2-add-source-2 &&
+	(
+		cd rename-rename-1to2-add-source-2 &&
+
+		>a &&
+		git add a &&
+		test_tick &&
+		git commit -m base &&
+		git tag A &&
+
+		git checkout -b B A &&
+		git mv a b &&
+		test_tick &&
+		git commit -m one &&
+
+		git checkout -b C A &&
+		git mv a b &&
+		echo important-info >a &&
+		git add a &&
+		test_tick &&
+		git commit -m two
+	)
+}
+
+test_expect_failure 'rename/rename/add-source still tracks new a file' '
+	test_setup_rename_rename_1to2_add_source_2 &&
+	(
+		cd rename-rename-1to2-add-source-2 &&
+
+		git checkout C^0 &&
+		git merge -s recursive B^0 &&
+
+		git ls-files -s >out &&
+		test_line_count = 2 out &&
+		git ls-files -o >out &&
+		test_line_count = 1 out &&
+
+		git rev-parse >expect \
+			C:a   A:a     &&
+		git rev-parse >actual \
+			:0:a  :0:b    &&
+		test_cmp expect actual
+	)
+'
+
+test_setup_rename_rename_1to2_add_dest () {
+	git init rename-rename-1to2-add-dest &&
+	(
+		cd rename-rename-1to2-add-dest &&
+
+		echo stuff >a &&
+		git add a &&
+		test_tick &&
+		git commit -m base &&
+		git tag A &&
+
+		git checkout -b B A &&
+		git mv a b &&
+		echo precious-data >c &&
+		git add c &&
+		test_tick &&
+		git commit -m one &&
+
+		git checkout -b C A &&
+		git mv a c &&
+		echo important-info >b &&
+		git add b &&
+		test_tick &&
+		git commit -m two
+	)
+}
+
+test_expect_success 'rename/rename/add-dest merge still knows about conflicting file versions' '
+	test_setup_rename_rename_1to2_add_dest &&
+	(
+		cd rename-rename-1to2-add-dest &&
+
+		git checkout C^0 &&
+		test_must_fail git merge -s recursive B^0 &&
+
+		git ls-files -s >out &&
+		test_line_count = 5 out &&
+		git ls-files -u b >out &&
+		test_line_count = 2 out &&
+		git ls-files -u c >out &&
+		test_line_count = 2 out &&
+		git ls-files -o >out &&
+		test_line_count = 1 out &&
+
+		git rev-parse >expect               \
+			A:a   C:b   B:b   C:c   B:c &&
+		git rev-parse >actual                \
+			:1:a  :2:b  :3:b  :2:c  :3:c &&
+		test_cmp expect actual &&
+
+		# Record some contents for re-doing merges
+		git cat-file -p A:a >stuff &&
+		git cat-file -p C:b >important_info &&
+		git cat-file -p B:c >precious_data &&
+		>empty &&
+
+		# Test the merge in b
+		test_must_fail git merge-file \
+			-L "HEAD" \
+			-L "" \
+			-L "B^0" \
+			important_info empty stuff &&
+		test_cmp important_info b &&
+
+		# Test the merge in c
+		test_must_fail git merge-file \
+			-L "HEAD" \
+			-L "" \
+			-L "B^0" \
+			stuff empty precious_data &&
+		test_cmp stuff c
+	)
+'
+
+# Testcase rad, rename/add/delete
+#   Commit O: foo
+#   Commit A: rm foo, add different bar
+#   Commit B: rename foo->bar
+#   Expected: CONFLICT (rename/add/delete), two-way merged bar
+
+test_setup_rad () {
+	git init rad &&
+	(
+		cd rad &&
+		echo "original file" >foo &&
+		git add foo &&
+		git commit -m "original" &&
+
+		git branch O &&
+		git branch A &&
+		git branch B &&
+
+		git checkout A &&
+		git rm foo &&
+		echo "different file" >bar &&
+		git add bar &&
+		git commit -m "Remove foo, add bar" &&
+
+		git checkout B &&
+		git mv foo bar &&
+		git commit -m "rename foo to bar"
+	)
+}
+
+test_expect_merge_algorithm failure success 'rad-check: rename/add/delete conflict' '
+	test_setup_rad &&
+	(
+		cd rad &&
+
+		git checkout B^0 &&
+		test_must_fail git merge -s recursive A^0 >out 2>err &&
+
+		# Instead of requiring the output to contain one combined line
+		#   CONFLICT (rename/add/delete)
+		# or perhaps two lines:
+		#   CONFLICT (rename/add): new file collides with rename target
+		#   CONFLICT (rename/delete): rename source removed on other side
+		# and instead of requiring "rename/add" instead of "add/add",
+		# be flexible in the type of console output message(s) reported
+		# for this particular case; we will be more stringent about the
+		# contents of the index and working directory.
+		test_i18ngrep "CONFLICT (.*/add)" out &&
+		test_i18ngrep "CONFLICT (rename.*/delete)" out &&
+		test_must_be_empty err &&
+
+		git ls-files -s >file_count &&
+		test_line_count = 2 file_count &&
+		git ls-files -u >file_count &&
+		test_line_count = 2 file_count &&
+		git ls-files -o >file_count &&
+		test_line_count = 3 file_count &&
+
+		git rev-parse >actual \
+			:2:bar :3:bar &&
+		git rev-parse >expect \
+			B:bar  A:bar  &&
+
+		test_path_is_missing foo &&
+		# bar should have two-way merged contents of the different
+		# versions of bar; check that content from both sides is
+		# present.
+		grep original bar &&
+		grep different bar
+	)
+'
+
+# Testcase rrdd, rename/rename(2to1)/delete/delete
+#   Commit O: foo, bar
+#   Commit A: rename foo->baz, rm bar
+#   Commit B: rename bar->baz, rm foo
+#   Expected: CONFLICT (rename/rename/delete/delete), two-way merged baz
+
+test_setup_rrdd () {
+	git init rrdd &&
+	(
+		cd rrdd &&
+		echo foo >foo &&
+		echo bar >bar &&
+		git add foo bar &&
+		git commit -m O &&
+
+		git branch O &&
+		git branch A &&
+		git branch B &&
+
+		git checkout A &&
+		git mv foo baz &&
+		git rm bar &&
+		git commit -m "Rename foo, remove bar" &&
+
+		git checkout B &&
+		git mv bar baz &&
+		git rm foo &&
+		git commit -m "Rename bar, remove foo"
+	)
+}
+
+test_expect_merge_algorithm failure success 'rrdd-check: rename/rename(2to1)/delete/delete conflict' '
+	test_setup_rrdd &&
+	(
+		cd rrdd &&
+
+		git checkout A^0 &&
+		test_must_fail git merge -s recursive B^0 >out 2>err &&
+
+		# Instead of requiring the output to contain one combined line
+		#   CONFLICT (rename/rename/delete/delete)
+		# or perhaps two lines:
+		#   CONFLICT (rename/rename): ...
+		#   CONFLICT (rename/delete): info about pair 1
+		#   CONFLICT (rename/delete): info about pair 2
+		# and instead of requiring "rename/rename" instead of "add/add",
+		# be flexible in the type of console output message(s) reported
+		# for this particular case; we will be more stringent about the
+		# contents of the index and working directory.
+		test_i18ngrep "CONFLICT (\(.*\)/\1)" out &&
+		test_i18ngrep "CONFLICT (rename.*delete)" out &&
+		test_must_be_empty err &&
+
+		git ls-files -s >file_count &&
+		test_line_count = 2 file_count &&
+		git ls-files -u >file_count &&
+		test_line_count = 2 file_count &&
+		git ls-files -o >file_count &&
+		test_line_count = 3 file_count &&
+
+		git rev-parse >actual \
+			:2:baz :3:baz &&
+		git rev-parse >expect \
+			O:foo  O:bar  &&
+
+		test_path_is_missing foo &&
+		test_path_is_missing bar &&
+		# baz should have two-way merged contents of the original
+		# contents of foo and bar; check that content from both sides
+		# is present.
+		grep foo baz &&
+		grep bar baz
+	)
+'
+
+# Testcase mod6, chains of rename/rename(1to2) and rename/rename(2to1)
+#   Commit O: one,      three,       five
+#   Commit A: one->two, three->four, five->six
+#   Commit B: one->six, three->two,  five->four
+#   Expected: six CONFLICT(rename/rename) messages, each path in two of the
+#             multi-way merged contents found in two, four, six
+
+test_setup_mod6 () {
+	git init mod6 &&
+	(
+		cd mod6 &&
+		test_seq 11 19 >one &&
+		test_seq 31 39 >three &&
+		test_seq 51 59 >five &&
+		git add . &&
+		test_tick &&
+		git commit -m "O" &&
+
+		git branch O &&
+		git branch A &&
+		git branch B &&
+
+		git checkout A &&
+		test_seq 10 19 >one &&
+		echo 40        >>three &&
+		git add one three &&
+		git mv  one   two  &&
+		git mv  three four &&
+		git mv  five  six  &&
+		test_tick &&
+		git commit -m "A" &&
+
+		git checkout B &&
+		echo 20    >>one       &&
+		echo forty >>three     &&
+		echo 60    >>five      &&
+		git add one three five &&
+		git mv  one   six  &&
+		git mv  three two  &&
+		git mv  five  four &&
+		test_tick &&
+		git commit -m "B"
+	)
+}
+
+test_expect_merge_algorithm failure success 'mod6-check: chains of rename/rename(1to2) and rename/rename(2to1)' '
+	test_setup_mod6 &&
+	(
+		cd mod6 &&
+
+		git checkout A^0 &&
+
+		test_must_fail git merge -s recursive B^0 >out 2>err &&
+
+		test_i18ngrep "CONFLICT (rename/rename)" out &&
+		test_must_be_empty err &&
+
+		git ls-files -s >file_count &&
+		test_line_count = 9 file_count &&
+		git ls-files -u >file_count &&
+		test_line_count = 9 file_count &&
+		git ls-files -o >file_count &&
+		test_line_count = 3 file_count &&
+
+		test_seq 10 20 >merged-one &&
+		test_seq 51 60 >merged-five &&
+		# Determine what the merge of three would give us.
+		test_seq 31 39 >three-base &&
+		test_seq 31 40 >three-side-A &&
+		test_seq 31 39 >three-side-B &&
+		echo forty >>three-side-B &&
+		test_must_fail git merge-file \
+			-L "HEAD:four" \
+			-L "" \
+			-L "B^0:two" \
+			three-side-A three-base three-side-B &&
+		sed -e "s/^\([<=>]\)/\1\1/" three-side-A >merged-three &&
+
+		# Verify the index is as expected
+		git rev-parse >actual         \
+			:2:two       :3:two   \
+			:2:four      :3:four  \
+			:2:six       :3:six   &&
+		git hash-object >expect           \
+			merged-one   merged-three \
+			merged-three merged-five  \
+			merged-five  merged-one   &&
+		test_cmp expect actual &&
+
+		git cat-file -p :2:two >expect &&
+		git cat-file -p :3:two >other &&
+		>empty &&
+		test_must_fail git merge-file    \
+			-L "HEAD"  -L ""  -L "B^0" \
+			expect     empty  other &&
+		test_cmp expect two &&
+
+		git cat-file -p :2:four >expect &&
+		git cat-file -p :3:four >other &&
+		test_must_fail git merge-file    \
+			-L "HEAD"  -L ""  -L "B^0" \
+			expect     empty  other &&
+		test_cmp expect four &&
+
+		git cat-file -p :2:six >expect &&
+		git cat-file -p :3:six >other &&
+		test_must_fail git merge-file    \
+			-L "HEAD"  -L ""  -L "B^0" \
+			expect     empty  other &&
+		test_cmp expect six
+	)
+'
+
+test_conflicts_with_adds_and_renames() {
+	sideL=$1
+	sideR=$2
+
+	# Setup:
+	#          L
+	#         / \
+	#     main   ?
+	#         \ /
+	#          R
+	#
+	# Where:
+	#   Both L and R have files named 'three' which collide.  Each of
+	#   the colliding files could have been involved in a rename, in
+	#   which case there was a file named 'one' or 'two' that was
+	#   modified on the opposite side of history and renamed into the
+	#   collision on this side of history.
+	#
+	# Questions:
+	#   1) The index should contain both a stage 2 and stage 3 entry
+	#      for the colliding file.  Does it?
+	#   2) When renames are involved, the content merges are clean, so
+	#      the index should reflect the content merges, not merely the
+	#      version of the colliding file from the prior commit.  Does
+	#      it?
+	#   3) There should be a file in the worktree named 'three'
+	#      containing the two-way merged contents of the content-merged
+	#      versions of 'three' from each of the two colliding
+	#      files.  Is it present?
+	#   4) There should not be any three~* files in the working
+	#      tree
+	test_setup_collision_conflict () {
+	#test_expect_success "setup simple $sideL/$sideR conflict" '
+		git init simple_${sideL}_${sideR} &&
+		(
+			cd simple_${sideL}_${sideR} &&
+
+			# Create some related files now
+			for i in $(test_seq 1 10)
+			do
+				echo Random base content line $i
+			done >file_v1 &&
+			cp file_v1 file_v2 &&
+			echo modification >>file_v2 &&
+
+			cp file_v1 file_v3 &&
+			echo more stuff >>file_v3 &&
+			cp file_v3 file_v4 &&
+			echo yet more stuff >>file_v4 &&
+
+			# Use a tag to record both these files for simple
+			# access, and clean out these untracked files
+			git tag file_v1 $(git hash-object -w file_v1) &&
+			git tag file_v2 $(git hash-object -w file_v2) &&
+			git tag file_v3 $(git hash-object -w file_v3) &&
+			git tag file_v4 $(git hash-object -w file_v4) &&
+			git clean -f &&
+
+			# Setup original commit (or merge-base), consisting of
+			# files named "one" and "two" if renames were involved.
+			touch irrelevant_file &&
+			git add irrelevant_file &&
+			if [ $sideL = "rename" ]
+			then
+				git show file_v1 >one &&
+				git add one
+			fi &&
+			if [ $sideR = "rename" ]
+			then
+				git show file_v3 >two &&
+				git add two
+			fi &&
+			test_tick && git commit -m initial &&
+
+			git branch L &&
+			git branch R &&
+
+			# Handle the left side
+			git checkout L &&
+			if [ $sideL = "rename" ]
+			then
+				git mv one three
+			else
+				git show file_v2 >three &&
+				git add three
+			fi &&
+			if [ $sideR = "rename" ]
+			then
+				git show file_v4 >two &&
+				git add two
+			fi &&
+			test_tick && git commit -m L &&
+
+			# Handle the right side
+			git checkout R &&
+			if [ $sideL = "rename" ]
+			then
+				git show file_v2 >one &&
+				git add one
+			fi &&
+			if [ $sideR = "rename" ]
+			then
+				git mv two three
+			else
+				git show file_v4 >three &&
+				git add three
+			fi &&
+			test_tick && git commit -m R
+		)
+	#'
+	}
+
+	test_expect_success "check simple $sideL/$sideR conflict" '
+		test_setup_collision_conflict &&
+		(
+			cd simple_${sideL}_${sideR} &&
+
+			git checkout L^0 &&
+
+			# Merge must fail; there is a conflict
+			test_must_fail git merge -s recursive R^0 &&
+
+			# Make sure the index has the right number of entries
+			git ls-files -s >out &&
+			test_line_count = 3 out &&
+			git ls-files -u >out &&
+			test_line_count = 2 out &&
+			# Ensure we have the correct number of untracked files
+			git ls-files -o >out &&
+			test_line_count = 1 out &&
+
+			# Nothing should have touched irrelevant_file
+			git rev-parse >actual      \
+				:0:irrelevant_file \
+				:2:three           \
+				:3:three           &&
+			git rev-parse >expected        \
+				main:irrelevant_file \
+				file_v2                \
+				file_v4                &&
+			test_cmp expected actual &&
+
+			# Make sure we have the correct merged contents for
+			# three
+			git show file_v1 >expected &&
+			cat <<-\EOF >>expected &&
+			<<<<<<< HEAD
+			modification
+			=======
+			more stuff
+			yet more stuff
+			>>>>>>> R^0
+			EOF
+
+			test_cmp expected three
+		)
+	'
+}
+
+test_conflicts_with_adds_and_renames rename rename
+test_conflicts_with_adds_and_renames rename add
+test_conflicts_with_adds_and_renames add    rename
+test_conflicts_with_adds_and_renames add    add
+
+# Setup:
+#          L
+#         / \
+#     main   ?
+#         \ /
+#          R
+#
+# Where:
+#   main has two files, named 'one' and 'two'.
+#   branches L and R both modify 'one', in conflicting ways.
+#   branches L and R both modify 'two', in conflicting ways.
+#   branch L also renames 'one' to 'three'.
+#   branch R also renames 'two' to 'three'.
+#
+#   So, we have four different conflicting files that all end up at path
+#   'three'.
+test_setup_nested_conflicts_from_rename_rename () {
+	git init nested_conflicts_from_rename_rename &&
+	(
+		cd nested_conflicts_from_rename_rename &&
+
+		# Create some related files now
+		for i in $(test_seq 1 10)
+		do
+			echo Random base content line $i
+		done >file_v1 &&
+
+		cp file_v1 file_v2 &&
+		cp file_v1 file_v3 &&
+		cp file_v1 file_v4 &&
+		cp file_v1 file_v5 &&
+		cp file_v1 file_v6 &&
+
+		echo one  >>file_v1 &&
+		echo uno  >>file_v2 &&
+		echo eins >>file_v3 &&
+
+		echo two  >>file_v4 &&
+		echo dos  >>file_v5 &&
+		echo zwei >>file_v6 &&
+
+		# Setup original commit (or merge-base), consisting of
+		# files named "one" and "two".
+		mv file_v1 one &&
+		mv file_v4 two &&
+		git add one two &&
+		test_tick && git commit -m english &&
+
+		git branch L &&
+		git branch R &&
+
+		# Handle the left side
+		git checkout L &&
+		git rm one two &&
+		mv -f file_v2 three &&
+		mv -f file_v5 two &&
+		git add two three &&
+		test_tick && git commit -m spanish &&
+
+		# Handle the right side
+		git checkout R &&
+		git rm one two &&
+		mv -f file_v3 one &&
+		mv -f file_v6 three &&
+		git add one three &&
+		test_tick && git commit -m german
+	)
+}
+
+test_expect_success 'check nested conflicts from rename/rename(2to1)' '
+	test_setup_nested_conflicts_from_rename_rename &&
+	(
+		cd nested_conflicts_from_rename_rename &&
+
+		git checkout L^0 &&
+
+		# Merge must fail; there is a conflict
+		test_must_fail git merge -s recursive R^0 &&
+
+		# Make sure the index has the right number of entries
+		git ls-files -s >out &&
+		test_line_count = 2 out &&
+		git ls-files -u >out &&
+		test_line_count = 2 out &&
+		# Ensure we have the correct number of untracked files
+		git ls-files -o >out &&
+		test_line_count = 1 out &&
+
+		# Compare :2:three to expected values
+		git cat-file -p main:one >base &&
+		git cat-file -p L:three >ours &&
+		git cat-file -p R:one >theirs &&
+		test_must_fail git merge-file    \
+			-L "HEAD:three"  -L ""  -L "R^0:one" \
+			ours             base   theirs &&
+		sed -e "s/^\([<=>]\)/\1\1/" ours >L-three &&
+		git cat-file -p :2:three >expect &&
+		test_cmp expect L-three &&
+
+		# Compare :2:three to expected values
+		git cat-file -p main:two >base &&
+		git cat-file -p L:two >ours &&
+		git cat-file -p R:three >theirs &&
+		test_must_fail git merge-file    \
+			-L "HEAD:two"  -L ""  -L "R^0:three" \
+			ours           base   theirs &&
+		sed -e "s/^\([<=>]\)/\1\1/" ours >R-three &&
+		git cat-file -p :3:three >expect &&
+		test_cmp expect R-three &&
+
+		# Compare three to expected contents
+		>empty &&
+		test_must_fail git merge-file    \
+			-L "HEAD"  -L ""  -L "R^0" \
+			L-three    empty  R-three &&
+		test_cmp three L-three
+	)
+'
+
+# Testcase rename/rename(1to2) of a binary file
+#   Commit O: orig
+#   Commit A: orig-A
+#   Commit B: orig-B
+#   Expected: CONFLICT(rename/rename) message, three unstaged entries in the
+#             index, and contents of orig-[AB] at path orig-[AB]
+test_setup_rename_rename_1_to_2_binary () {
+	git init rename_rename_1_to_2_binary &&
+	(
+		cd rename_rename_1_to_2_binary &&
+
+		echo '* binary' >.gitattributes &&
+		git add .gitattributes &&
+
+		test_seq 1 10 >orig &&
+		git add orig &&
+		git commit -m orig &&
+
+		git branch A &&
+		git branch B &&
+
+		git checkout A &&
+		git mv orig orig-A &&
+		test_seq 1 11 >orig-A &&
+		git add orig-A &&
+		git commit -m orig-A &&
+
+		git checkout B &&
+		git mv orig orig-B &&
+		test_seq 0 10 >orig-B &&
+		git add orig-B &&
+		git commit -m orig-B
+
+	)
+}
+
+test_expect_success 'rename/rename(1to2) with a binary file' '
+	test_setup_rename_rename_1_to_2_binary &&
+	(
+		cd rename_rename_1_to_2_binary &&
+
+		git checkout A^0 &&
+
+		test_must_fail git merge -s recursive B^0 &&
+
+		# Make sure the index has the right number of entries
+		git ls-files -s >actual &&
+		test_line_count = 4 actual &&
+
+		git rev-parse A:orig-A B:orig-B >expect &&
+		git hash-object orig-A orig-B >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_done