#!/bin/sh

test_description="recursive merge with directory renames"
# includes checking of many corner cases, with a similar methodology to:
#   t6042: corner cases with renames but not criss-cross merges
#   t6036: corner cases with both renames and criss-cross merges
#
# 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


###########################################################################
# SECTION 1: Basic cases we should be able to handle
###########################################################################

# Testcase 1a, Basic directory rename.
#   Commit O: z/{b,c}
#   Commit A: y/{b,c}
#   Commit B: z/{b,c,d,e/f}
#   Expected: y/{b,c,d,e/f}

test_expect_success '1a-setup: Simple directory rename detection' '
	test_create_repo 1a &&
	(
		cd 1a &&

		mkdir z &&
		echo b >z/b &&
		echo c >z/c &&
		git add z &&
		test_tick &&
		git commit -m "O" &&

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

		git checkout A &&
		git mv z y &&
		test_tick &&
		git commit -m "A" &&

		git checkout B &&
		echo d >z/d &&
		mkdir z/e &&
		echo f >z/e/f &&
		git add z/d z/e/f &&
		test_tick &&
		git commit -m "B"
	)
'

test_expect_failure '1a-check: Simple directory rename detection' '
	(
		cd 1a &&

		git checkout A^0 &&

		git merge -s recursive B^0 &&

		test 4 -eq $(git ls-files -s | wc -l) &&

		git rev-parse >actual \
			HEAD:y/b HEAD:y/c HEAD:y/d HEAD:y/e/f &&
		git rev-parse >expect \
			O:z/b O:z/c B:z/d B:z/e/f &&
		test_cmp expect actual &&
		test "$(git hash-object y/d)" = $(git rev-parse B:z/d) &&
		test_must_fail git rev-parse HEAD:z/d &&
		test_must_fail git rev-parse HEAD:z/e/f &&
		test ! -d z/d &&
		test ! -d z/e/f
	)
'

# Testcase 1b, Merge a directory with another
#   Commit O: z/{b,c},   y/d
#   Commit A: z/{b,c,e}, y/d
#   Commit B: y/{b,c,d}
#   Expected: y/{b,c,d,e}

test_expect_success '1b-setup: Merge a directory with another' '
	test_create_repo 1b &&
	(
		cd 1b &&

		mkdir z &&
		echo b >z/b &&
		echo c >z/c &&
		mkdir y &&
		echo d >y/d &&
		git add z y &&
		test_tick &&
		git commit -m "O" &&

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

		git checkout A &&
		echo e >z/e &&
		git add z/e &&
		test_tick &&
		git commit -m "A" &&

		git checkout B &&
		git mv z/b y &&
		git mv z/c y &&
		rmdir z &&
		test_tick &&
		git commit -m "B"
	)
'

test_expect_failure '1b-check: Merge a directory with another' '
	(
		cd 1b &&

		git checkout A^0 &&

		git merge -s recursive B^0 &&

		test 4 -eq $(git ls-files -s | wc -l) &&

		git rev-parse >actual \
			HEAD:y/b HEAD:y/c HEAD:y/d HEAD:y/e &&
		git rev-parse >expect \
			O:z/b O:z/c O:y/d A:z/e &&
		test_cmp expect actual &&
		test_must_fail git rev-parse HEAD:z/e
	)
'

# Testcase 1c, Transitive renaming
#   (Related to testcases 3a and 6d -- when should a transitive rename apply?)
#   (Related to testcases 9c and 9d -- can transitivity repeat?)
#   Commit O: z/{b,c},   x/d
#   Commit A: y/{b,c},   x/d
#   Commit B: z/{b,c,d}
#   Expected: y/{b,c,d}  (because x/d -> z/d -> y/d)

test_expect_success '1c-setup: Transitive renaming' '
	test_create_repo 1c &&
	(
		cd 1c &&

		mkdir z &&
		echo b >z/b &&
		echo c >z/c &&
		mkdir x &&
		echo d >x/d &&
		git add z x &&
		test_tick &&
		git commit -m "O" &&

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

		git checkout A &&
		git mv z y &&
		test_tick &&
		git commit -m "A" &&

		git checkout B &&
		git mv x/d z/d &&
		test_tick &&
		git commit -m "B"
	)
'

test_expect_failure '1c-check: Transitive renaming' '
	(
		cd 1c &&

		git checkout A^0 &&

		git merge -s recursive B^0 &&

		test 3 -eq $(git ls-files -s | wc -l) &&

		git rev-parse >actual \
			HEAD:y/b HEAD:y/c HEAD:y/d &&
		git rev-parse >expect \
			O:z/b O:z/c O:x/d &&
		test_cmp expect actual &&
		test_must_fail git rev-parse HEAD:x/d &&
		test_must_fail git rev-parse HEAD:z/d &&
		test ! -f z/d
	)
'

# Testcase 1d, Directory renames (merging two directories into one new one)
#              cause a rename/rename(2to1) conflict
#   (Related to testcases 1c and 7b)
#   Commit O. z/{b,c},        y/{d,e}
#   Commit A. x/{b,c},        y/{d,e,m,wham_1}
#   Commit B. z/{b,c,n,wham_2}, x/{d,e}
#   Expected: x/{b,c,d,e,m,n}, CONFLICT:(y/wham_1 & z/wham_2 -> x/wham)
#   Note: y/m & z/n should definitely move into x.  By the same token, both
#         y/wham_1 & z/wham_2 should too...giving us a conflict.

test_expect_success '1d-setup: Directory renames cause a rename/rename(2to1) conflict' '
	test_create_repo 1d &&
	(
		cd 1d &&

		mkdir z &&
		echo b >z/b &&
		echo c >z/c &&
		mkdir y &&
		echo d >y/d &&
		echo e >y/e &&
		git add z y &&
		test_tick &&
		git commit -m "O" &&

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

		git checkout A &&
		git mv z x &&
		echo m >y/m &&
		echo wham1 >y/wham &&
		git add y &&
		test_tick &&
		git commit -m "A" &&

		git checkout B &&
		git mv y x &&
		echo n >z/n &&
		echo wham2 >z/wham &&
		git add z &&
		test_tick &&
		git commit -m "B"
	)
'

test_expect_failure '1d-check: Directory renames cause a rename/rename(2to1) conflict' '
	(
		cd 1d &&

		git checkout A^0 &&

		test_must_fail git merge -s recursive B^0 >out &&
		test_i18ngrep "CONFLICT (rename/rename)" out &&

		test 8 -eq $(git ls-files -s | wc -l) &&
		test 2 -eq $(git ls-files -u | wc -l) &&
		test 3 -eq $(git ls-files -o | wc -l) &&

		git rev-parse >actual \
			:0:x/b :0:x/c :0:x/d :0:x/e :0:x/m :0:x/n &&
		git rev-parse >expect \
			O:z/b O:z/c O:y/d O:y/e A:y/m B:z/n &&
		test_cmp expect actual &&

		test_must_fail git rev-parse :0:x/wham &&
		git rev-parse >actual \
			:2:x/wham :3:x/wham &&
		git rev-parse >expect \
			A:y/wham B:z/wham &&
		test_cmp expect actual &&

		test ! -f x/wham &&
		test -f x/wham~HEAD &&
		test -f x/wham~B^0 &&

		git hash-object >actual \
			x/wham~HEAD x/wham~B^0 &&
		git rev-parse >expect \
			A:y/wham B:z/wham &&
		test_cmp expect actual
	)
'

# Testcase 1e, Renamed directory, with all filenames being renamed too
#   Commit O: z/{oldb,oldc}
#   Commit A: y/{newb,newc}
#   Commit B: z/{oldb,oldc,d}
#   Expected: y/{newb,newc,d}

test_expect_success '1e-setup: Renamed directory, with all files being renamed too' '
	test_create_repo 1e &&
	(
		cd 1e &&

		mkdir z &&
		echo b >z/oldb &&
		echo c >z/oldc &&
		git add z &&
		test_tick &&
		git commit -m "O" &&

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

		git checkout A &&
		mkdir y &&
		git mv z/oldb y/newb &&
		git mv z/oldc y/newc &&
		test_tick &&
		git commit -m "A" &&

		git checkout B &&
		echo d >z/d &&
		git add z/d &&
		test_tick &&
		git commit -m "B"
	)
'

test_expect_failure '1e-check: Renamed directory, with all files being renamed too' '
	(
		cd 1e &&

		git checkout A^0 &&

		git merge -s recursive B^0 &&

		test 3 -eq $(git ls-files -s | wc -l) &&

		git rev-parse >actual \
			HEAD:y/newb HEAD:y/newc HEAD:y/d &&
		git rev-parse >expect \
			O:z/oldb O:z/oldc B:z/d &&
		test_cmp expect actual &&
		test_must_fail git rev-parse HEAD:z/d
	)
'

# Testcase 1f, Split a directory into two other directories
#   (Related to testcases 3a, all of section 2, and all of section 4)
#   Commit O: z/{b,c,d,e,f}
#   Commit A: z/{b,c,d,e,f,g}
#   Commit B: y/{b,c}, x/{d,e,f}
#   Expected: y/{b,c}, x/{d,e,f,g}

test_expect_success '1f-setup: Split a directory into two other directories' '
	test_create_repo 1f &&
	(
		cd 1f &&

		mkdir z &&
		echo b >z/b &&
		echo c >z/c &&
		echo d >z/d &&
		echo e >z/e &&
		echo f >z/f &&
		git add z &&
		test_tick &&
		git commit -m "O" &&

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

		git checkout A &&
		echo g >z/g &&
		git add z/g &&
		test_tick &&
		git commit -m "A" &&

		git checkout B &&
		mkdir y &&
		mkdir x &&
		git mv z/b y/ &&
		git mv z/c y/ &&
		git mv z/d x/ &&
		git mv z/e x/ &&
		git mv z/f x/ &&
		rmdir z &&
		test_tick &&
		git commit -m "B"
	)
'

test_expect_failure '1f-check: Split a directory into two other directories' '
	(
		cd 1f &&

		git checkout A^0 &&

		git merge -s recursive B^0 &&

		test 6 -eq $(git ls-files -s | wc -l) &&

		git rev-parse >actual \
			HEAD:y/b HEAD:y/c HEAD:x/d HEAD:x/e HEAD:x/f HEAD:x/g &&
		git rev-parse >expect \
			O:z/b O:z/c O:z/d O:z/e O:z/f A:z/g &&
		test_cmp expect actual &&
		test ! -f z/g &&
		test_must_fail git rev-parse HEAD:z/g
	)
'

###########################################################################
# Rules suggested by testcases in section 1:
#
#   We should still detect the directory rename even if it wasn't just
#   the directory renamed, but the files within it. (see 1b)
#
#   If renames split a directory into two or more others, the directory
#   with the most renames, "wins" (see 1c).  However, see the testcases
#   in section 2, plus testcases 3a and 4a.
###########################################################################

test_done