t/t6426-merge-skip-unneeded-updates.sh - jrn/git - Git at Google

 #!/bin/sh

 test_description="merge cases"

 # The setup for all of them, pictorially, is:
 #
 #      A
 #      o
 #     / \
 #  O o   ?
 #     \ /
 #      o
 #      B
 #
 # To help make it easier to follow the flow of tests, they have been
 # divided into sections and each test will start with a quick explanation
 # of what commits O, A, and B contain.
 #
 # Notation:
 #    z/{b,c}   means  files z/b and z/c both exist
 #    x/d_1     means  file x/d exists with content d1.  (Purpose of the
 #                     underscore notation is to differentiate different
 #                     files that might be renamed into each other's paths.)

 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-merge.sh


 ###########################################################################
 # SECTION 1: Cases involving no renames (one side has subset of changes of
 #            the other side)
 ###########################################################################

 # Testcase 1a, Changes on A, subset of changes on B
 #   Commit O: b_1
 #   Commit A: b_2
 #   Commit B: b_3
 #   Expected: b_2

 test_setup_1a () {
 	git init 1a_$1 &&
 	(
 		cd 1a_$1 &&

 		test_write_lines 1 2 3 4 5 6 7 8 9 10 >b &&
 		git add b &&
 		test_tick &&
 		git commit -m "O" &&

 		git branch O &&
 		git branch A &&
 		git branch B &&

 		git checkout A &&
 		test_write_lines 1 2 3 4 5 5.5 6 7 8 9 10 10.5 >b &&
 		git add b &&
 		test_tick &&
 		git commit -m "A" &&

 		git checkout B &&
 		test_write_lines 1 2 3 4 5 5.5 6 7 8 9 10 >b &&
 		git add b &&
 		test_tick &&
 		git commit -m "B"
 	)
 }

 test_expect_success '1a-L: Modify(A)/Modify(B), change on B subset of A' '
 	test_setup_1a L &&
 	(
 		cd 1a_L &&

 		git checkout A^0 &&

 		test-tool chmtime --get -3600 b >old-mtime &&

 		GIT_MERGE_VERBOSITY=3 git merge -s recursive B^0 >out 2>err &&

 		test_must_be_empty err &&

 		# Make sure b was NOT updated
 		test-tool chmtime --get b >new-mtime &&
 		test_cmp old-mtime new-mtime &&

 		git ls-files -s >index_files &&
 		test_line_count = 1 index_files &&

 		git rev-parse >actual HEAD:b &&
 		git rev-parse >expect A:b &&
 		test_cmp expect actual &&

 		git hash-object b   >actual &&
 		git rev-parse   A:b >expect &&
 		test_cmp expect actual
 	)
 '

 test_expect_success '1a-R: Modify(A)/Modify(B), change on B subset of A' '
 	test_setup_1a R &&
 	(
 		cd 1a_R &&

 		git checkout B^0 &&

 		test-tool chmtime --get -3600 b >old-mtime &&
 		GIT_MERGE_VERBOSITY=3 git merge -s recursive A^0 >out 2>err &&

 		# Make sure b WAS updated
 		test-tool chmtime --get b >new-mtime &&
 		test $(cat old-mtime) -lt $(cat new-mtime) &&

 		test_must_be_empty err &&

 		git ls-files -s >index_files &&
 		test_line_count = 1 index_files &&

 		git rev-parse >actual HEAD:b &&
 		git rev-parse >expect A:b &&
 		test_cmp expect actual &&

 		git hash-object b   >actual &&
 		git rev-parse   A:b >expect &&
 		test_cmp expect actual
 	)
 '


 ###########################################################################
 # SECTION 2: Cases involving basic renames
 ###########################################################################

 # Testcase 2a, Changes on A, rename on B
 #   Commit O: b_1
 #   Commit A: b_2
 #   Commit B: c_1
 #   Expected: c_2

 test_setup_2a () {
 	git init 2a_$1 &&
 	(
 		cd 2a_$1 &&

 		test_seq 1 10 >b &&
 		git add b &&
 		test_tick &&
 		git commit -m "O" &&

 		git branch O &&
 		git branch A &&
 		git branch B &&

 		git checkout A &&
 		test_seq 1 11 >b &&
 		git add b &&
 		test_tick &&
 		git commit -m "A" &&

 		git checkout B &&
 		git mv b c &&
 		test_tick &&
 		git commit -m "B"
 	)
 }

 test_expect_success '2a-L: Modify/rename, merge into modify side' '
 	test_setup_2a L &&
 	(
 		cd 2a_L &&

 		git checkout A^0 &&

 		test_path_is_missing c &&
 		GIT_MERGE_VERBOSITY=3 git merge -s recursive B^0 >out 2>err &&

 		test_path_is_file c &&

 		git ls-files -s >index_files &&
 		test_line_count = 1 index_files &&

 		git rev-parse >actual HEAD:c &&
 		git rev-parse >expect A:b &&
 		test_cmp expect actual &&

 		git hash-object c   >actual &&
 		git rev-parse   A:b >expect &&
 		test_cmp expect actual &&

 		test_must_fail git rev-parse HEAD:b &&
 		test_path_is_missing b
 	)
 '

 test_expect_success '2a-R: Modify/rename, merge into rename side' '
 	test_setup_2a R &&
 	(
 		cd 2a_R &&

 		git checkout B^0 &&

 		test-tool chmtime --get -3600 c >old-mtime &&
 		GIT_MERGE_VERBOSITY=3 git merge -s recursive A^0 >out 2>err &&

 		# Make sure c WAS updated
 		test-tool chmtime --get c >new-mtime &&
 		test $(cat old-mtime) -lt $(cat new-mtime) &&

 		test_must_be_empty err &&

 		git ls-files -s >index_files &&
 		test_line_count = 1 index_files &&

 		git rev-parse >actual HEAD:c &&
 		git rev-parse >expect A:b &&
 		test_cmp expect actual &&

 		git hash-object c   >actual &&
 		git rev-parse   A:b >expect &&
 		test_cmp expect actual &&

 		test_must_fail git rev-parse HEAD:b &&
 		test_path_is_missing b
 	)
 '

 # Testcase 2b, Changed and renamed on A, subset of changes on B
 #   Commit O: b_1
 #   Commit A: c_2
 #   Commit B: b_3
 #   Expected: c_2

 test_setup_2b () {
 	git init 2b_$1 &&
 	(
 		cd 2b_$1 &&

 		test_write_lines 1 2 3 4 5 6 7 8 9 10 >b &&
 		git add b &&
 		test_tick &&
 		git commit -m "O" &&

 		git branch O &&
 		git branch A &&
 		git branch B &&

 		git checkout A &&
 		test_write_lines 1 2 3 4 5 5.5 6 7 8 9 10 10.5 >b &&
 		git add b &&
 		git mv b c &&
 		test_tick &&
 		git commit -m "A" &&

 		git checkout B &&
 		test_write_lines 1 2 3 4 5 5.5 6 7 8 9 10 >b &&
 		git add b &&
 		test_tick &&
 		git commit -m "B"
 	)
 }

 test_expect_success '2b-L: Rename+Mod(A)/Mod(B), B mods subset of A' '
 	test_setup_2b L &&
 	(
 		cd 2b_L &&

 		git checkout A^0 &&

 		test-tool chmtime --get -3600 c >old-mtime &&
 		GIT_MERGE_VERBOSITY=3 git merge -s recursive B^0 >out 2>err &&

 		test_must_be_empty err &&

 		# Make sure c WAS updated
 		test-tool chmtime --get c >new-mtime &&
 		test_cmp old-mtime new-mtime &&

 		git ls-files -s >index_files &&
 		test_line_count = 1 index_files &&

 		git rev-parse >actual HEAD:c &&
 		git rev-parse >expect A:c &&
 		test_cmp expect actual &&

 		git hash-object c   >actual &&
 		git rev-parse   A:c >expect &&
 		test_cmp expect actual &&

 		test_must_fail git rev-parse HEAD:b &&
 		test_path_is_missing b
 	)
 '

 test_expect_success '2b-R: Rename+Mod(A)/Mod(B), B mods subset of A' '
 	test_setup_2b R &&
 	(
 		cd 2b_R &&

 		git checkout B^0 &&

 		test_path_is_missing c &&
 		GIT_MERGE_VERBOSITY=3 git merge -s recursive A^0 >out 2>err &&

 		# Make sure c now present (and thus was updated)
 		test_path_is_file c &&

 		test_must_be_empty err &&

 		git ls-files -s >index_files &&
 		test_line_count = 1 index_files &&

 		git rev-parse >actual HEAD:c &&
 		git rev-parse >expect A:c &&
 		test_cmp expect actual &&

 		git hash-object c   >actual &&
 		git rev-parse   A:c >expect &&
 		test_cmp expect actual &&

 		test_must_fail git rev-parse HEAD:b &&
 		test_path_is_missing b
 	)
 '

 # Testcase 2c, Changes on A, rename on B
 #   Commit O: b_1
 #   Commit A: b_2, c_3
 #   Commit B: c_1
 #   Expected: rename/add conflict c_2 vs c_3
 #
 #   NOTE: Since A modified b_1->b_2, and B renamed b_1->c_1, the threeway
 #         merge of those files should result in c_2.  We then should have a
 #         rename/add conflict between c_2 and c_3.  However, if we note in
 #         merge_content() that A had the right contents (b_2 has same
 #         contents as c_2, just at a different name), and that A had the
 #         right path present (c_3 existed) and thus decides that it can
 #         skip the update, then we're in trouble.  This test verifies we do
 #         not make that particular mistake.

 test_setup_2c () {
 	git init 2c &&
 	(
 		cd 2c &&

 		test_seq 1 10 >b &&
 		git add b &&
 		test_tick &&
 		git commit -m "O" &&

 		git branch O &&
 		git branch A &&
 		git branch B &&

 		git checkout A &&
 		test_seq 1 11 >b &&
 		echo whatever >c &&
 		git add b c &&
 		test_tick &&
 		git commit -m "A" &&

 		git checkout B &&
 		git mv b c &&
 		test_tick &&
 		git commit -m "B"
 	)
 }

 test_expect_success '2c: Modify b & add c VS rename b->c' '
 	test_setup_2c &&
 	(
 		cd 2c &&

 		git checkout A^0 &&

 		test-tool chmtime --get -3600 c >old-mtime &&
 		GIT_MERGE_VERBOSITY=3 &&
 		export GIT_MERGE_VERBOSITY &&
 		test_must_fail git merge -s recursive B^0 >out 2>err &&

 		test_grep "CONFLICT (.*/add):" out &&
 		test_must_be_empty err &&

 		git ls-files -s >index_files &&
 		test_line_count = 2 index_files &&

 		# Ensure b was removed
 		test_path_is_missing b &&

 		# Make sure c WAS updated...
 		test-tool chmtime --get c >new-mtime &&
 		test $(cat old-mtime) -lt $(cat new-mtime) &&

 		# ...and has correct index entries and working tree contents
 		git rev-parse >actual :2:c :3:c &&
 		git rev-parse >expect A:c  A:b  &&
 		test_cmp expect actual &&

 		git cat-file -p A:b >>merge-me &&
 		git cat-file -p A:c >>merged &&
 		>empty &&
 		test_must_fail git merge-file \
 			-L "HEAD" \
 			-L "" \
 			-L "B^0" \
 			merged empty merge-me &&
 		test_cmp merged c
 	)
 '


 ###########################################################################
 # SECTION 3: Cases involving directory renames
 #
 # NOTE:
 #   Directory renames only apply when one side renames a directory, and the
 #   other side adds or renames a path into that directory.  Applying the
 #   directory rename to that new path creates a new pathname that didn't
 #   exist on either side of history.  Thus, it is impossible for the
 #   merge contents to already be at the right path, so all of these checks
 #   exist just to make sure that updates are not skipped.
 ###########################################################################

 # Testcase 3a, Change + rename into dir foo on A, dir rename foo->bar on B
 #   Commit O: bq_1, foo/whatever
 #   Commit A: foo/{bq_2, whatever}
 #   Commit B: bq_1, bar/whatever
 #   Expected: bar/{bq_2, whatever}

 test_setup_3a () {
 	git init 3a_$1 &&
 	(
 		cd 3a_$1 &&

 		mkdir foo &&
 		test_seq 1 10 >bq &&
 		test_write_lines a b c d e f g h i j k >foo/whatever &&
 		git add bq foo/whatever &&
 		test_tick &&
 		git commit -m "O" &&

 		git branch O &&
 		git branch A &&
 		git branch B &&

 		git checkout A &&
 		test_seq 1 11 >bq &&
 		git add bq &&
 		git mv bq foo/ &&
 		test_tick &&
 		git commit -m "A" &&

 		git checkout B &&
 		git mv foo/ bar/ &&
 		test_tick &&
 		git commit -m "B"
 	)
 }

 test_expect_success '3a-L: bq_1->foo/bq_2 on A, foo/->bar/ on B' '
 	test_setup_3a L &&
 	(
 		cd 3a_L &&

 		git checkout A^0 &&

 		test_path_is_missing bar/bq &&
 		GIT_MERGE_VERBOSITY=3 git -c merge.directoryRenames=true merge -s recursive B^0 >out 2>err &&

 		test_must_be_empty err &&

 		test_path_is_file bar/bq &&

 		git ls-files -s >index_files &&
 		test_line_count = 2 index_files &&

 		git rev-parse >actual HEAD:bar/bq HEAD:bar/whatever &&
 		git rev-parse >expect A:foo/bq    A:foo/whatever &&
 		test_cmp expect actual &&

 		git hash-object bar/bq   bar/whatever   >actual &&
 		git rev-parse   A:foo/bq A:foo/whatever >expect &&
 		test_cmp expect actual &&

 		test_must_fail git rev-parse HEAD:bq HEAD:foo/bq &&
 		test_path_is_missing bq &&
 		test_path_is_missing foo/bq &&
 		test_path_is_missing foo/whatever
 	)
 '

 test_expect_success '3a-R: bq_1->foo/bq_2 on A, foo/->bar/ on B' '
 	test_setup_3a R &&
 	(
 		cd 3a_R &&

 		git checkout B^0 &&

 		test_path_is_missing bar/bq &&
 		GIT_MERGE_VERBOSITY=3 git -c merge.directoryRenames=true merge -s recursive A^0 >out 2>err &&

 		test_must_be_empty err &&

 		test_path_is_file bar/bq &&

 		git ls-files -s >index_files &&
 		test_line_count = 2 index_files &&

 		git rev-parse >actual HEAD:bar/bq HEAD:bar/whatever &&
 		git rev-parse >expect A:foo/bq    A:foo/whatever &&
 		test_cmp expect actual &&

 		git hash-object bar/bq   bar/whatever   >actual &&
 		git rev-parse   A:foo/bq A:foo/whatever >expect &&
 		test_cmp expect actual &&

 		test_must_fail git rev-parse HEAD:bq HEAD:foo/bq &&
 		test_path_is_missing bq &&
 		test_path_is_missing foo/bq &&
 		test_path_is_missing foo/whatever
 	)
 '

 # Testcase 3b, rename into dir foo on A, dir rename foo->bar + change on B
 #   Commit O: bq_1, foo/whatever
 #   Commit A: foo/{bq_1, whatever}
 #   Commit B: bq_2, bar/whatever
 #   Expected: bar/{bq_2, whatever}

 test_setup_3b () {
 	git init 3b_$1 &&
 	(
 		cd 3b_$1 &&

 		mkdir foo &&
 		test_seq 1 10 >bq &&
 		test_write_lines a b c d e f g h i j k >foo/whatever &&
 		git add bq foo/whatever &&
 		test_tick &&
 		git commit -m "O" &&

 		git branch O &&
 		git branch A &&
 		git branch B &&

 		git checkout A &&
 		git mv bq foo/ &&
 		test_tick &&
 		git commit -m "A" &&

 		git checkout B &&
 		test_seq 1 11 >bq &&
 		git add bq &&
 		git mv foo/ bar/ &&
 		test_tick &&
 		git commit -m "B"
 	)
 }

 test_expect_success '3b-L: bq_1->foo/bq_2 on A, foo/->bar/ on B' '
 	test_setup_3b L &&
 	(
 		cd 3b_L &&

 		git checkout A^0 &&

 		test_path_is_missing bar/bq &&
 		GIT_MERGE_VERBOSITY=3 git -c merge.directoryRenames=true merge -s recursive B^0 >out 2>err &&

 		test_must_be_empty err &&

 		test_path_is_file bar/bq &&

 		git ls-files -s >index_files &&
 		test_line_count = 2 index_files &&

 		git rev-parse >actual HEAD:bar/bq HEAD:bar/whatever &&
 		git rev-parse >expect B:bq        A:foo/whatever &&
 		test_cmp expect actual &&

 		git hash-object bar/bq bar/whatever   >actual &&
 		git rev-parse   B:bq   A:foo/whatever >expect &&
 		test_cmp expect actual &&

 		test_must_fail git rev-parse HEAD:bq HEAD:foo/bq &&
 		test_path_is_missing bq &&
 		test_path_is_missing foo/bq &&
 		test_path_is_missing foo/whatever
 	)
 '

 test_expect_success '3b-R: bq_1->foo/bq_2 on A, foo/->bar/ on B' '
 	test_setup_3b R &&
 	(
 		cd 3b_R &&

 		git checkout B^0 &&

 		test_path_is_missing bar/bq &&
 		GIT_MERGE_VERBOSITY=3 git -c merge.directoryRenames=true merge -s recursive A^0 >out 2>err &&

 		test_must_be_empty err &&

 		test_path_is_file bar/bq &&

 		git ls-files -s >index_files &&
 		test_line_count = 2 index_files &&

 		git rev-parse >actual HEAD:bar/bq HEAD:bar/whatever &&
 		git rev-parse >expect B:bq        A:foo/whatever &&
 		test_cmp expect actual &&

 		git hash-object bar/bq bar/whatever   >actual &&
 		git rev-parse   B:bq   A:foo/whatever >expect &&
 		test_cmp expect actual &&

 		test_must_fail git rev-parse HEAD:bq HEAD:foo/bq &&
 		test_path_is_missing bq &&
 		test_path_is_missing foo/bq &&
 		test_path_is_missing foo/whatever
 	)
 '

 ###########################################################################
 # SECTION 4: Cases involving dirty changes
 ###########################################################################

 # Testcase 4a, Changed on A, subset of changes on B, locally modified
 #   Commit O: b_1
 #   Commit A: b_2
 #   Commit B: b_3
 #   Working copy: b_4
 #   Expected: b_2 for merge, b_4 in working copy

 test_setup_4a () {
 	git init 4a &&
 	(
 		cd 4a &&

 		test_write_lines 1 2 3 4 5 6 7 8 9 10 >b &&
 		git add b &&
 		test_tick &&
 		git commit -m "O" &&

 		git branch O &&
 		git branch A &&
 		git branch B &&

 		git checkout A &&
 		test_write_lines 1 2 3 4 5 5.5 6 7 8 9 10 10.5 >b &&
 		git add b &&
 		test_tick &&
 		git commit -m "A" &&

 		git checkout B &&
 		test_write_lines 1 2 3 4 5 5.5 6 7 8 9 10 >b &&
 		git add b &&
 		test_tick &&
 		git commit -m "B"
 	)
 }

 # NOTE: For as long as we continue using unpack_trees() without index_only
 #   set to true, it will error out on a case like this claiming that the locally
 #   modified file would be overwritten by the merge.  Getting this testcase
 #   correct requires doing the merge in-memory first, then realizing that no
 #   updates to the file are necessary, and thus that we can just leave the path
 #   alone.
 test_expect_merge_algorithm failure success '4a: Change on A, change on B subset of A, dirty mods present' '
 	test_setup_4a &&
 	(
 		cd 4a &&

 		git checkout A^0 &&
 		echo "File rewritten" >b &&

 		test-tool chmtime --get -3600 b >old-mtime &&

 		GIT_MERGE_VERBOSITY=3 git merge -s recursive B^0 >out 2>err &&

 		test_must_be_empty err &&

 		# Make sure b was NOT updated
 		test-tool chmtime --get b >new-mtime &&
 		test_cmp old-mtime new-mtime &&

 		git ls-files -s >index_files &&
 		test_line_count = 1 index_files &&

 		git rev-parse >actual :0:b &&
 		git rev-parse >expect A:b &&
 		test_cmp expect actual &&

 		git hash-object b >actual &&
 		echo "File rewritten" | git hash-object --stdin >expect &&
 		test_cmp expect actual
 	)
 '

 # Testcase 4b, Changed+renamed on A, subset of changes on B, locally modified
 #   Commit O: b_1
 #   Commit A: c_2
 #   Commit B: b_3
 #   Working copy: c_4
 #   Expected: c_2

 test_setup_4b () {
 	git init 4b &&
 	(
 		cd 4b &&

 		test_write_lines 1 2 3 4 5 6 7 8 9 10 >b &&
 		git add b &&
 		test_tick &&
 		git commit -m "O" &&

 		git branch O &&
 		git branch A &&
 		git branch B &&

 		git checkout A &&
 		test_write_lines 1 2 3 4 5 5.5 6 7 8 9 10 10.5 >b &&
 		git add b &&
 		git mv b c &&
 		test_tick &&
 		git commit -m "A" &&

 		git checkout B &&
 		test_write_lines 1 2 3 4 5 5.5 6 7 8 9 10 >b &&
 		git add b &&
 		test_tick &&
 		git commit -m "B"
 	)
 }

 test_expect_success '4b: Rename+Mod(A)/Mod(B), change on B subset of A, dirty mods present' '
 	test_setup_4b &&
 	(
 		cd 4b &&

 		git checkout A^0 &&
 		echo "File rewritten" >c &&

 		test-tool chmtime --get -3600 c >old-mtime &&

 		GIT_MERGE_VERBOSITY=3 git merge -s recursive B^0 >out 2>err &&

 		test_must_be_empty err &&

 		# Make sure c was NOT updated
 		test-tool chmtime --get c >new-mtime &&
 		test_cmp old-mtime new-mtime &&

 		git ls-files -s >index_files &&
 		test_line_count = 1 index_files &&

 		git rev-parse >actual :0:c &&
 		git rev-parse >expect A:c &&
 		test_cmp expect actual &&

 		git hash-object c >actual &&
 		echo "File rewritten" | git hash-object --stdin >expect &&
 		test_cmp expect actual &&

 		test_must_fail git rev-parse HEAD:b &&
 		test_path_is_missing b
 	)
 '

 test_done
	#!/bin/sh

	test_description="merge cases"

	# The setup for all of them, pictorially, is:
	#
	# A
	# o
	# / \
	# O o ?
	# \ /
	# o
	# B
	#
	# To help make it easier to follow the flow of tests, they have been
	# divided into sections and each test will start with a quick explanation
	# of what commits O, A, and B contain.
	#
	# Notation:
	# z/{b,c} means files z/b and z/c both exist
	# x/d_1 means file x/d exists with content d1. (Purpose of the
	# underscore notation is to differentiate different
	# files that might be renamed into each other's paths.)

	. ./test-lib.sh
	. "$TEST_DIRECTORY"/lib-merge.sh


	###########################################################################
	# SECTION 1: Cases involving no renames (one side has subset of changes of
	# the other side)
	###########################################################################

	# Testcase 1a, Changes on A, subset of changes on B
	# Commit O: b_1
	# Commit A: b_2
	# Commit B: b_3
	# Expected: b_2

	test_setup_1a () {
	git init 1a_$1 &&
	(
	cd 1a_$1 &&

	test_write_lines 1 2 3 4 5 6 7 8 9 10 >b &&
	git add b &&
	test_tick &&
	git commit -m "O" &&

	git branch O &&
	git branch A &&
	git branch B &&

	git checkout A &&
	test_write_lines 1 2 3 4 5 5.5 6 7 8 9 10 10.5 >b &&
	git add b &&
	test_tick &&
	git commit -m "A" &&

	git checkout B &&
	test_write_lines 1 2 3 4 5 5.5 6 7 8 9 10 >b &&
	git add b &&
	test_tick &&
	git commit -m "B"
	)
	}

	test_expect_success '1a-L: Modify(A)/Modify(B), change on B subset of A' '
	test_setup_1a L &&
	(
	cd 1a_L &&

	git checkout A^0 &&

	test-tool chmtime --get -3600 b >old-mtime &&

	GIT_MERGE_VERBOSITY=3 git merge -s recursive B^0 >out 2>err &&

	test_must_be_empty err &&

	# Make sure b was NOT updated
	test-tool chmtime --get b >new-mtime &&
	test_cmp old-mtime new-mtime &&

	git ls-files -s >index_files &&
	test_line_count = 1 index_files &&

	git rev-parse >actual HEAD:b &&
	git rev-parse >expect A:b &&
	test_cmp expect actual &&

	git hash-object b >actual &&
	git rev-parse A:b >expect &&
	test_cmp expect actual
	)
	'

	test_expect_success '1a-R: Modify(A)/Modify(B), change on B subset of A' '
	test_setup_1a R &&
	(
	cd 1a_R &&

	git checkout B^0 &&

	test-tool chmtime --get -3600 b >old-mtime &&
	GIT_MERGE_VERBOSITY=3 git merge -s recursive A^0 >out 2>err &&

	# Make sure b WAS updated
	test-tool chmtime --get b >new-mtime &&
	test $(cat old-mtime) -lt $(cat new-mtime) &&

	test_must_be_empty err &&

	git ls-files -s >index_files &&
	test_line_count = 1 index_files &&

	git rev-parse >actual HEAD:b &&
	git rev-parse >expect A:b &&
	test_cmp expect actual &&

	git hash-object b >actual &&
	git rev-parse A:b >expect &&
	test_cmp expect actual
	)
	'


	###########################################################################
	# SECTION 2: Cases involving basic renames
	###########################################################################

	# Testcase 2a, Changes on A, rename on B
	# Commit O: b_1
	# Commit A: b_2
	# Commit B: c_1
	# Expected: c_2

	test_setup_2a () {
	git init 2a_$1 &&
	(
	cd 2a_$1 &&

	test_seq 1 10 >b &&
	git add b &&
	test_tick &&
	git commit -m "O" &&

	git branch O &&
	git branch A &&
	git branch B &&

	git checkout A &&
	test_seq 1 11 >b &&
	git add b &&
	test_tick &&
	git commit -m "A" &&

	git checkout B &&
	git mv b c &&
	test_tick &&
	git commit -m "B"
	)
	}

	test_expect_success '2a-L: Modify/rename, merge into modify side' '
	test_setup_2a L &&
	(
	cd 2a_L &&

	git checkout A^0 &&

	test_path_is_missing c &&
	GIT_MERGE_VERBOSITY=3 git merge -s recursive B^0 >out 2>err &&

	test_path_is_file c &&

	git ls-files -s >index_files &&
	test_line_count = 1 index_files &&

	git rev-parse >actual HEAD:c &&
	git rev-parse >expect A:b &&
	test_cmp expect actual &&

	git hash-object c >actual &&
	git rev-parse A:b >expect &&
	test_cmp expect actual &&

	test_must_fail git rev-parse HEAD:b &&
	test_path_is_missing b
	)
	'

	test_expect_success '2a-R: Modify/rename, merge into rename side' '
	test_setup_2a R &&
	(
	cd 2a_R &&

	git checkout B^0 &&

	test-tool chmtime --get -3600 c >old-mtime &&
	GIT_MERGE_VERBOSITY=3 git merge -s recursive A^0 >out 2>err &&

	# Make sure c WAS updated
	test-tool chmtime --get c >new-mtime &&
	test $(cat old-mtime) -lt $(cat new-mtime) &&

	test_must_be_empty err &&

	git ls-files -s >index_files &&
	test_line_count = 1 index_files &&

	git rev-parse >actual HEAD:c &&
	git rev-parse >expect A:b &&
	test_cmp expect actual &&

	git hash-object c >actual &&
	git rev-parse A:b >expect &&
	test_cmp expect actual &&

	test_must_fail git rev-parse HEAD:b &&
	test_path_is_missing b
	)
	'

	# Testcase 2b, Changed and renamed on A, subset of changes on B
	# Commit O: b_1
	# Commit A: c_2
	# Commit B: b_3
	# Expected: c_2

	test_setup_2b () {
	git init 2b_$1 &&
	(
	cd 2b_$1 &&

	test_write_lines 1 2 3 4 5 6 7 8 9 10 >b &&
	git add b &&
	test_tick &&
	git commit -m "O" &&

	git branch O &&
	git branch A &&
	git branch B &&

	git checkout A &&
	test_write_lines 1 2 3 4 5 5.5 6 7 8 9 10 10.5 >b &&
	git add b &&
	git mv b c &&
	test_tick &&
	git commit -m "A" &&

	git checkout B &&
	test_write_lines 1 2 3 4 5 5.5 6 7 8 9 10 >b &&
	git add b &&
	test_tick &&
	git commit -m "B"
	)
	}

	test_expect_success '2b-L: Rename+Mod(A)/Mod(B), B mods subset of A' '
	test_setup_2b L &&
	(
	cd 2b_L &&

	git checkout A^0 &&

	test-tool chmtime --get -3600 c >old-mtime &&
	GIT_MERGE_VERBOSITY=3 git merge -s recursive B^0 >out 2>err &&

	test_must_be_empty err &&

	# Make sure c WAS updated
	test-tool chmtime --get c >new-mtime &&
	test_cmp old-mtime new-mtime &&

	git ls-files -s >index_files &&
	test_line_count = 1 index_files &&

	git rev-parse >actual HEAD:c &&
	git rev-parse >expect A:c &&
	test_cmp expect actual &&

	git hash-object c >actual &&
	git rev-parse A:c >expect &&
	test_cmp expect actual &&

	test_must_fail git rev-parse HEAD:b &&
	test_path_is_missing b
	)
	'

	test_expect_success '2b-R: Rename+Mod(A)/Mod(B), B mods subset of A' '
	test_setup_2b R &&
	(
	cd 2b_R &&

	git checkout B^0 &&

	test_path_is_missing c &&
	GIT_MERGE_VERBOSITY=3 git merge -s recursive A^0 >out 2>err &&

	# Make sure c now present (and thus was updated)
	test_path_is_file c &&

	test_must_be_empty err &&

	git ls-files -s >index_files &&
	test_line_count = 1 index_files &&

	git rev-parse >actual HEAD:c &&
	git rev-parse >expect A:c &&
	test_cmp expect actual &&

	git hash-object c >actual &&
	git rev-parse A:c >expect &&
	test_cmp expect actual &&

	test_must_fail git rev-parse HEAD:b &&
	test_path_is_missing b
	)
	'

	# Testcase 2c, Changes on A, rename on B
	# Commit O: b_1
	# Commit A: b_2, c_3
	# Commit B: c_1
	# Expected: rename/add conflict c_2 vs c_3
	#
	# NOTE: Since A modified b_1->b_2, and B renamed b_1->c_1, the threeway
	# merge of those files should result in c_2. We then should have a
	# rename/add conflict between c_2 and c_3. However, if we note in
	# merge_content() that A had the right contents (b_2 has same
	# contents as c_2, just at a different name), and that A had the
	# right path present (c_3 existed) and thus decides that it can
	# skip the update, then we're in trouble. This test verifies we do
	# not make that particular mistake.

	test_setup_2c () {
	git init 2c &&
	(
	cd 2c &&

	test_seq 1 10 >b &&
	git add b &&
	test_tick &&
	git commit -m "O" &&

	git branch O &&
	git branch A &&
	git branch B &&

	git checkout A &&
	test_seq 1 11 >b &&
	echo whatever >c &&
	git add b c &&
	test_tick &&
	git commit -m "A" &&

	git checkout B &&
	git mv b c &&
	test_tick &&
	git commit -m "B"
	)
	}

	test_expect_success '2c: Modify b & add c VS rename b->c' '
	test_setup_2c &&
	(
	cd 2c &&

	git checkout A^0 &&

	test-tool chmtime --get -3600 c >old-mtime &&
	GIT_MERGE_VERBOSITY=3 &&
	export GIT_MERGE_VERBOSITY &&
	test_must_fail git merge -s recursive B^0 >out 2>err &&

	test_grep "CONFLICT (.*/add):" out &&
	test_must_be_empty err &&

	git ls-files -s >index_files &&
	test_line_count = 2 index_files &&

	# Ensure b was removed
	test_path_is_missing b &&

	# Make sure c WAS updated...
	test-tool chmtime --get c >new-mtime &&
	test $(cat old-mtime) -lt $(cat new-mtime) &&

	# ...and has correct index entries and working tree contents
	git rev-parse >actual :2:c :3:c &&
	git rev-parse >expect A:c A:b &&
	test_cmp expect actual &&

	git cat-file -p A:b >>merge-me &&
	git cat-file -p A:c >>merged &&
	>empty &&
	test_must_fail git merge-file \
	-L "HEAD" \
	-L "" \
	-L "B^0" \
	merged empty merge-me &&
	test_cmp merged c
	)
	'


	###########################################################################
	# SECTION 3: Cases involving directory renames
	#
	# NOTE:
	# Directory renames only apply when one side renames a directory, and the
	# other side adds or renames a path into that directory. Applying the
	# directory rename to that new path creates a new pathname that didn't
	# exist on either side of history. Thus, it is impossible for the
	# merge contents to already be at the right path, so all of these checks
	# exist just to make sure that updates are not skipped.
	###########################################################################

	# Testcase 3a, Change + rename into dir foo on A, dir rename foo->bar on B
	# Commit O: bq_1, foo/whatever
	# Commit A: foo/{bq_2, whatever}
	# Commit B: bq_1, bar/whatever
	# Expected: bar/{bq_2, whatever}

	test_setup_3a () {
	git init 3a_$1 &&
	(
	cd 3a_$1 &&

	mkdir foo &&
	test_seq 1 10 >bq &&
	test_write_lines a b c d e f g h i j k >foo/whatever &&
	git add bq foo/whatever &&
	test_tick &&
	git commit -m "O" &&

	git branch O &&
	git branch A &&
	git branch B &&

	git checkout A &&
	test_seq 1 11 >bq &&
	git add bq &&
	git mv bq foo/ &&
	test_tick &&
	git commit -m "A" &&

	git checkout B &&
	git mv foo/ bar/ &&
	test_tick &&
	git commit -m "B"
	)
	}

	test_expect_success '3a-L: bq_1->foo/bq_2 on A, foo/->bar/ on B' '
	test_setup_3a L &&
	(
	cd 3a_L &&

	git checkout A^0 &&

	test_path_is_missing bar/bq &&
	GIT_MERGE_VERBOSITY=3 git -c merge.directoryRenames=true merge -s recursive B^0 >out 2>err &&

	test_must_be_empty err &&

	test_path_is_file bar/bq &&

	git ls-files -s >index_files &&
	test_line_count = 2 index_files &&

	git rev-parse >actual HEAD:bar/bq HEAD:bar/whatever &&
	git rev-parse >expect A:foo/bq A:foo/whatever &&
	test_cmp expect actual &&

	git hash-object bar/bq bar/whatever >actual &&
	git rev-parse A:foo/bq A:foo/whatever >expect &&
	test_cmp expect actual &&

	test_must_fail git rev-parse HEAD:bq HEAD:foo/bq &&
	test_path_is_missing bq &&
	test_path_is_missing foo/bq &&
	test_path_is_missing foo/whatever
	)
	'

	test_expect_success '3a-R: bq_1->foo/bq_2 on A, foo/->bar/ on B' '
	test_setup_3a R &&
	(
	cd 3a_R &&

	git checkout B^0 &&

	test_path_is_missing bar/bq &&
	GIT_MERGE_VERBOSITY=3 git -c merge.directoryRenames=true merge -s recursive A^0 >out 2>err &&

	test_must_be_empty err &&

	test_path_is_file bar/bq &&

	git ls-files -s >index_files &&
	test_line_count = 2 index_files &&

	git rev-parse >actual HEAD:bar/bq HEAD:bar/whatever &&
	git rev-parse >expect A:foo/bq A:foo/whatever &&
	test_cmp expect actual &&

	git hash-object bar/bq bar/whatever >actual &&
	git rev-parse A:foo/bq A:foo/whatever >expect &&
	test_cmp expect actual &&

	test_must_fail git rev-parse HEAD:bq HEAD:foo/bq &&
	test_path_is_missing bq &&
	test_path_is_missing foo/bq &&
	test_path_is_missing foo/whatever
	)
	'

	# Testcase 3b, rename into dir foo on A, dir rename foo->bar + change on B
	# Commit O: bq_1, foo/whatever
	# Commit A: foo/{bq_1, whatever}
	# Commit B: bq_2, bar/whatever
	# Expected: bar/{bq_2, whatever}

	test_setup_3b () {
	git init 3b_$1 &&
	(
	cd 3b_$1 &&

	mkdir foo &&
	test_seq 1 10 >bq &&
	test_write_lines a b c d e f g h i j k >foo/whatever &&
	git add bq foo/whatever &&
	test_tick &&
	git commit -m "O" &&

	git branch O &&
	git branch A &&
	git branch B &&

	git checkout A &&
	git mv bq foo/ &&
	test_tick &&
	git commit -m "A" &&

	git checkout B &&
	test_seq 1 11 >bq &&
	git add bq &&
	git mv foo/ bar/ &&
	test_tick &&
	git commit -m "B"
	)
	}

	test_expect_success '3b-L: bq_1->foo/bq_2 on A, foo/->bar/ on B' '
	test_setup_3b L &&
	(
	cd 3b_L &&

	git checkout A^0 &&

	test_path_is_missing bar/bq &&
	GIT_MERGE_VERBOSITY=3 git -c merge.directoryRenames=true merge -s recursive B^0 >out 2>err &&

	test_must_be_empty err &&

	test_path_is_file bar/bq &&

	git ls-files -s >index_files &&
	test_line_count = 2 index_files &&

	git rev-parse >actual HEAD:bar/bq HEAD:bar/whatever &&
	git rev-parse >expect B:bq A:foo/whatever &&
	test_cmp expect actual &&

	git hash-object bar/bq bar/whatever >actual &&
	git rev-parse B:bq A:foo/whatever >expect &&
	test_cmp expect actual &&

	test_must_fail git rev-parse HEAD:bq HEAD:foo/bq &&
	test_path_is_missing bq &&
	test_path_is_missing foo/bq &&
	test_path_is_missing foo/whatever
	)
	'

	test_expect_success '3b-R: bq_1->foo/bq_2 on A, foo/->bar/ on B' '
	test_setup_3b R &&
	(
	cd 3b_R &&

	git checkout B^0 &&

	test_path_is_missing bar/bq &&
	GIT_MERGE_VERBOSITY=3 git -c merge.directoryRenames=true merge -s recursive A^0 >out 2>err &&

	test_must_be_empty err &&

	test_path_is_file bar/bq &&

	git ls-files -s >index_files &&
	test_line_count = 2 index_files &&

	git rev-parse >actual HEAD:bar/bq HEAD:bar/whatever &&
	git rev-parse >expect B:bq A:foo/whatever &&
	test_cmp expect actual &&

	git hash-object bar/bq bar/whatever >actual &&
	git rev-parse B:bq A:foo/whatever >expect &&
	test_cmp expect actual &&

	test_must_fail git rev-parse HEAD:bq HEAD:foo/bq &&
	test_path_is_missing bq &&
	test_path_is_missing foo/bq &&
	test_path_is_missing foo/whatever
	)
	'

	###########################################################################
	# SECTION 4: Cases involving dirty changes
	###########################################################################

	# Testcase 4a, Changed on A, subset of changes on B, locally modified
	# Commit O: b_1
	# Commit A: b_2
	# Commit B: b_3
	# Working copy: b_4
	# Expected: b_2 for merge, b_4 in working copy

	test_setup_4a () {
	git init 4a &&
	(
	cd 4a &&

	test_write_lines 1 2 3 4 5 6 7 8 9 10 >b &&
	git add b &&
	test_tick &&
	git commit -m "O" &&

	git branch O &&
	git branch A &&
	git branch B &&

	git checkout A &&
	test_write_lines 1 2 3 4 5 5.5 6 7 8 9 10 10.5 >b &&
	git add b &&
	test_tick &&
	git commit -m "A" &&

	git checkout B &&
	test_write_lines 1 2 3 4 5 5.5 6 7 8 9 10 >b &&
	git add b &&
	test_tick &&
	git commit -m "B"
	)
	}

	# NOTE: For as long as we continue using unpack_trees() without index_only
	# set to true, it will error out on a case like this claiming that the locally
	# modified file would be overwritten by the merge. Getting this testcase
	# correct requires doing the merge in-memory first, then realizing that no
	# updates to the file are necessary, and thus that we can just leave the path
	# alone.
	test_expect_merge_algorithm failure success '4a: Change on A, change on B subset of A, dirty mods present' '
	test_setup_4a &&
	(
	cd 4a &&

	git checkout A^0 &&
	echo "File rewritten" >b &&

	test-tool chmtime --get -3600 b >old-mtime &&

	GIT_MERGE_VERBOSITY=3 git merge -s recursive B^0 >out 2>err &&

	test_must_be_empty err &&

	# Make sure b was NOT updated
	test-tool chmtime --get b >new-mtime &&
	test_cmp old-mtime new-mtime &&

	git ls-files -s >index_files &&
	test_line_count = 1 index_files &&

	git rev-parse >actual :0:b &&
	git rev-parse >expect A:b &&
	test_cmp expect actual &&

	git hash-object b >actual &&
	echo "File rewritten" \| git hash-object --stdin >expect &&
	test_cmp expect actual
	)
	'

	# Testcase 4b, Changed+renamed on A, subset of changes on B, locally modified
	# Commit O: b_1
	# Commit A: c_2
	# Commit B: b_3
	# Working copy: c_4
	# Expected: c_2

	test_setup_4b () {
	git init 4b &&
	(
	cd 4b &&

	test_write_lines 1 2 3 4 5 6 7 8 9 10 >b &&
	git add b &&
	test_tick &&
	git commit -m "O" &&

	git branch O &&
	git branch A &&
	git branch B &&

	git checkout A &&
	test_write_lines 1 2 3 4 5 5.5 6 7 8 9 10 10.5 >b &&
	git add b &&
	git mv b c &&
	test_tick &&
	git commit -m "A" &&

	git checkout B &&
	test_write_lines 1 2 3 4 5 5.5 6 7 8 9 10 >b &&
	git add b &&
	test_tick &&
	git commit -m "B"
	)
	}

	test_expect_success '4b: Rename+Mod(A)/Mod(B), change on B subset of A, dirty mods present' '
	test_setup_4b &&
	(
	cd 4b &&

	git checkout A^0 &&
	echo "File rewritten" >c &&

	test-tool chmtime --get -3600 c >old-mtime &&

	GIT_MERGE_VERBOSITY=3 git merge -s recursive B^0 >out 2>err &&

	test_must_be_empty err &&

	# Make sure c was NOT updated
	test-tool chmtime --get c >new-mtime &&
	test_cmp old-mtime new-mtime &&

	git ls-files -s >index_files &&
	test_line_count = 1 index_files &&

	git rev-parse >actual :0:c &&
	git rev-parse >expect A:c &&
	test_cmp expect actual &&

	git hash-object c >actual &&
	echo "File rewritten" \| git hash-object --stdin >expect &&
	test_cmp expect actual &&

	test_must_fail git rev-parse HEAD:b &&
	test_path_is_missing b
	)
	'

	test_done