t/t1001-read-tree-m-2way.sh - git - Git at Google

 #!/bin/sh
 #
 # Copyright (c) 2005 Junio C Hamano
 #

 test_description='Two way merge with read-tree -m $H $M

 This test tries two-way merge (aka fast-forward with carry forward).

 There is the head (called H) and another commit (called M), which is
 simply ahead of H.  The index and the work tree contains a state that
 is derived from H, but may also have local changes.  This test checks
 all the combinations described in the two-tree merge "carry forward"
 rules, found in <Documentation/git read-tree.txt>.

 In the test, these paths are used:
 	bozbar  - in H, stays in M, modified from bozbar to gnusto
 	frotz   - not in H added in M
 	nitfol  - in H, stays in M unmodified
 	rezrov  - in H, deleted in M
 	yomin   - not in H or M
 '
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-read-tree.sh

 read_tree_twoway () {
     git read-tree -m "$1" "$2" && git ls-files --stage
 }

 compare_change () {
 	sed -n >current \
 	    -e '/^--- /d; /^+++ /d; /^@@ /d;' \
 	    -e 's/^\([-+][0-7][0-7][0-7][0-7][0-7][0-7]\) '"$OID_REGEX"' /\1 X /p' \
 	    "$1"
 	test_cmp expected current
 }

 check_cache_at () {
 	clean_if_empty=$(git diff-files -- "$1")
 	case "$clean_if_empty" in
 	'')  echo "$1: clean" ;;
 	?*)  echo "$1: dirty" ;;
 	esac
 	case "$2,$clean_if_empty" in
 	clean,)		:     ;;
 	clean,?*)	false ;;
 	dirty,)		false ;;
 	dirty,?*)	:     ;;
 	esac
 }

 cat >bozbar-old <<\EOF
 This is a sample file used in two-way fast-forward merge
 tests.  Its second line ends with a magic word bozbar
 which will be modified by the merged head to gnusto.
 It has some extra lines so that external tools can
 successfully merge independent changes made to later
 lines (such as this one), avoiding line conflicts.
 EOF

 sed -e 's/bozbar/gnusto (earlier bozbar)/' bozbar-old >bozbar-new

 test_expect_success 'setup' '
 	echo frotz >frotz &&
 	echo nitfol >nitfol &&
 	cat bozbar-old >bozbar &&
 	echo rezrov >rezrov &&
 	echo yomin >yomin &&
 	git update-index --add nitfol bozbar rezrov &&
 	treeH=$(git write-tree) &&
 	echo treeH $treeH &&
 	git ls-tree $treeH &&

 	cat bozbar-new >bozbar &&
 	git update-index --add frotz bozbar --force-remove rezrov &&
 	git ls-files --stage >M.out &&
 	treeM=$(git write-tree) &&
 	echo treeM $treeM &&
 	git ls-tree $treeM &&
 	git diff-tree $treeH $treeM
 '

 test_expect_success '1, 2, 3 - no carry forward' '
 	rm -f .git/index &&
 	read_tree_twoway $treeH $treeM &&
 	git ls-files --stage >1-3.out &&
 	test_cmp M.out 1-3.out &&
 	check_cache_at bozbar dirty &&
 	check_cache_at frotz dirty &&
 	check_cache_at nitfol dirty
 '
 echo '+100644 X 0	yomin' >expected

 test_expect_success '4 - carry forward local addition.' '
 	rm -f .git/index &&
 	read_tree_must_succeed $treeH &&
 	git checkout-index -u -f -q -a &&
 	git update-index --add yomin &&
 	read_tree_twoway $treeH $treeM &&
 	git ls-files --stage >4.out &&
 	test_must_fail git diff --no-index M.out 4.out >4diff.out &&
 	compare_change 4diff.out expected &&
 	check_cache_at yomin clean
 '

 test_expect_success '5 - carry forward local addition.' '
 	rm -f .git/index &&
 	read_tree_must_succeed $treeH &&
 	git checkout-index -u -f -q -a &&
 	echo yomin >yomin &&
 	git update-index --add yomin &&
 	echo yomin yomin >yomin &&
 	read_tree_twoway $treeH $treeM &&
 	git ls-files --stage >5.out &&
 	test_must_fail git diff --no-index M.out 5.out >5diff.out &&
 	compare_change 5diff.out expected &&
 	check_cache_at yomin dirty
 '

 test_expect_success '6 - local addition already has the same.' '
 	rm -f .git/index &&
 	read_tree_must_succeed $treeH &&
 	git checkout-index -u -f -q -a &&
 	git update-index --add frotz &&
 	read_tree_twoway $treeH $treeM &&
 	git ls-files --stage >6.out &&
 	test_cmp M.out 6.out &&
 	check_cache_at frotz clean
 '

 test_expect_success '7 - local addition already has the same.' '
 	rm -f .git/index &&
 	read_tree_must_succeed $treeH &&
 	git checkout-index -u -f -q -a &&
 	echo frotz >frotz &&
 	git update-index --add frotz &&
 	echo frotz frotz >frotz &&
 	read_tree_twoway $treeH $treeM &&
 	git ls-files --stage >7.out &&
 	test_cmp M.out 7.out &&
 	check_cache_at frotz dirty
 '

 test_expect_success '8 - conflicting addition.' '
 	rm -f .git/index &&
 	read_tree_must_succeed $treeH &&
 	git checkout-index -u -f -q -a &&
 	echo frotz frotz >frotz &&
 	git update-index --add frotz &&
 	if read_tree_twoway $treeH $treeM; then false; else :; fi
 '

 test_expect_success '9 - conflicting addition.' '
 	rm -f .git/index &&
 	read_tree_must_succeed $treeH &&
 	git checkout-index -u -f -q -a &&
 	echo frotz frotz >frotz &&
 	git update-index --add frotz &&
 	echo frotz >frotz &&
 	if read_tree_twoway $treeH $treeM; then false; else :; fi
 '

 test_expect_success '10 - path removed.' '
 	rm -f .git/index &&
 	read_tree_must_succeed $treeH &&
 	git checkout-index -u -f -q -a &&
 	echo rezrov >rezrov &&
 	git update-index --add rezrov &&
 	read_tree_twoway $treeH $treeM &&
 	git ls-files --stage >10.out &&
 	test_cmp M.out 10.out
 '

 test_expect_success '11 - dirty path removed.' '
 	rm -f .git/index &&
 	read_tree_must_succeed $treeH &&
 	git checkout-index -u -f -q -a &&
 	echo rezrov >rezrov &&
 	git update-index --add rezrov &&
 	echo rezrov rezrov >rezrov &&
 	if read_tree_twoway $treeH $treeM; then false; else :; fi
 '

 test_expect_success '12 - unmatching local changes being removed.' '
 	rm -f .git/index &&
 	read_tree_must_succeed $treeH &&
 	git checkout-index -u -f -q -a &&
 	echo rezrov rezrov >rezrov &&
 	git update-index --add rezrov &&
 	if read_tree_twoway $treeH $treeM; then false; else :; fi
 '

 test_expect_success '13 - unmatching local changes being removed.' '
 	rm -f .git/index &&
 	read_tree_must_succeed $treeH &&
 	git checkout-index -u -f -q -a &&
 	echo rezrov rezrov >rezrov &&
 	git update-index --add rezrov &&
 	echo rezrov >rezrov &&
 	if read_tree_twoway $treeH $treeM; then false; else :; fi
 '

 cat >expected <<EOF
 -100644 X 0	nitfol
 +100644 X 0	nitfol
 EOF

 test_expect_success '14 - unchanged in two heads.' '
 	rm -f .git/index &&
 	read_tree_must_succeed $treeH &&
 	git checkout-index -u -f -q -a &&
 	echo nitfol nitfol >nitfol &&
 	git update-index --add nitfol &&
 	read_tree_twoway $treeH $treeM &&
 	git ls-files --stage >14.out &&
 	test_must_fail git diff --no-index M.out 14.out >14diff.out &&
 	compare_change 14diff.out expected &&
 	check_cache_at nitfol clean
 '

 test_expect_success '15 - unchanged in two heads.' '
 	rm -f .git/index &&
 	read_tree_must_succeed $treeH &&
 	git checkout-index -u -f -q -a &&
 	echo nitfol nitfol >nitfol &&
 	git update-index --add nitfol &&
 	echo nitfol nitfol nitfol >nitfol &&
 	read_tree_twoway $treeH $treeM &&
 	git ls-files --stage >15.out &&
 	test_must_fail git diff --no-index M.out 15.out >15diff.out &&
 	compare_change 15diff.out expected &&
 	check_cache_at nitfol dirty
 '

 test_expect_success '16 - conflicting local change.' '
 	rm -f .git/index &&
 	read_tree_must_succeed $treeH &&
 	git checkout-index -u -f -q -a &&
 	echo bozbar bozbar >bozbar &&
 	git update-index --add bozbar &&
 	if read_tree_twoway $treeH $treeM; then false; else :; fi
 '

 test_expect_success '17 - conflicting local change.' '
 	rm -f .git/index &&
 	read_tree_must_succeed $treeH &&
 	git checkout-index -u -f -q -a &&
 	echo bozbar bozbar >bozbar &&
 	git update-index --add bozbar &&
 	echo bozbar bozbar bozbar >bozbar &&
 	if read_tree_twoway $treeH $treeM; then false; else :; fi
 '

 test_expect_success '18 - local change already having a good result.' '
 	rm -f .git/index &&
 	read_tree_must_succeed $treeH &&
 	git checkout-index -u -f -q -a &&
 	cat bozbar-new >bozbar &&
 	git update-index --add bozbar &&
 	read_tree_twoway $treeH $treeM &&
 	git ls-files --stage >18.out &&
 	test_cmp M.out 18.out &&
 	check_cache_at bozbar clean
 '

 test_expect_success '19 - local change already having a good result, further modified.' '
 	rm -f .git/index &&
 	read_tree_must_succeed $treeH &&
 	git checkout-index -u -f -q -a &&
 	cat bozbar-new >bozbar &&
 	git update-index --add bozbar &&
 	echo gnusto gnusto >bozbar &&
 	read_tree_twoway $treeH $treeM &&
 	git ls-files --stage >19.out &&
 	test_cmp M.out 19.out &&
 	check_cache_at bozbar dirty
 '

 test_expect_success '20 - no local change, use new tree.' '
 	rm -f .git/index &&
 	read_tree_must_succeed $treeH &&
 	git checkout-index -u -f -q -a &&
 	cat bozbar-old >bozbar &&
 	git update-index --add bozbar &&
 	read_tree_twoway $treeH $treeM &&
 	git ls-files --stage >20.out &&
 	test_cmp M.out 20.out &&
 	check_cache_at bozbar dirty
 '

 test_expect_success '21 - no local change, dirty cache.' '
 	rm -f .git/index &&
 	read_tree_must_succeed $treeH &&
 	git checkout-index -u -f -q -a &&
 	cat bozbar-old >bozbar &&
 	git update-index --add bozbar &&
 	echo gnusto gnusto >bozbar &&
 	if read_tree_twoway $treeH $treeM; then false; else :; fi
 '

 # This fails with straight two-way fast-forward.
 test_expect_success '22 - local change cache updated.' '
 	rm -f .git/index &&
 	read_tree_must_succeed $treeH &&
 	git checkout-index -u -f -q -a &&
 	sed -e "s/such as/SUCH AS/" bozbar-old >bozbar &&
 	git update-index --add bozbar &&
 	if read_tree_twoway $treeH $treeM; then false; else :; fi
 '

 # Also make sure we did not break DF vs DF/DF case.
 test_expect_success 'DF vs DF/DF case setup.' '
 	rm -f .git/index &&
 	echo DF >DF &&
 	git update-index --add DF &&
 	treeDF=$(git write-tree) &&
 	echo treeDF $treeDF &&
 	git ls-tree $treeDF &&

 	rm -f DF &&
 	mkdir DF &&
 	echo DF/DF >DF/DF &&
 	git update-index --add --remove DF DF/DF &&
 	treeDFDF=$(git write-tree) &&
 	echo treeDFDF $treeDFDF &&
 	git ls-tree $treeDFDF &&
 	git ls-files --stage >DFDF.out
 '

 test_expect_success 'DF vs DF/DF case test.' '
 	rm -f .git/index &&
 	rm -fr DF &&
 	echo DF >DF &&
 	git update-index --add DF &&
 	read_tree_twoway $treeDF $treeDFDF &&
 	git ls-files --stage >DFDFcheck.out &&
 	test_cmp DFDF.out DFDFcheck.out &&
 	check_cache_at DF/DF dirty &&
 	:
 '

 test_expect_success 'a/b (untracked) vs a case setup.' '
 	rm -f .git/index &&
 	: >a &&
 	git update-index --add a &&
 	treeM=$(git write-tree) &&
 	echo treeM $treeM &&
 	git ls-tree $treeM &&
 	git ls-files --stage >treeM.out &&

 	rm -f a &&
 	git update-index --remove a &&
 	mkdir a &&
 	: >a/b &&
 	treeH=$(git write-tree) &&
 	echo treeH $treeH &&
 	git ls-tree $treeH
 '

 test_expect_success 'a/b (untracked) vs a, plus c/d case test.' '
 	read_tree_u_must_fail -u -m "$treeH" "$treeM" &&
 	git ls-files --stage &&
 	test -f a/b
 '

 test_expect_success 'read-tree supports the super-prefix' '
 	cat <<-EOF >expect &&
 		error: Updating '\''fictional/a'\'' would lose untracked files in it
 	EOF
 	test_must_fail git --super-prefix fictional/ read-tree -u -m "$treeH" "$treeM" 2>actual &&
 	test_cmp expect actual
 '

 test_expect_success 'a/b vs a, plus c/d case setup.' '
 	rm -f .git/index &&
 	rm -fr a &&
 	: >a &&
 	mkdir c &&
 	: >c/d &&
 	git update-index --add a c/d &&
 	treeM=$(git write-tree) &&
 	echo treeM $treeM &&
 	git ls-tree $treeM &&
 	git ls-files --stage >treeM.out &&

 	rm -f a &&
 	mkdir a &&
 	: >a/b &&
 	git update-index --add --remove a a/b &&
 	treeH=$(git write-tree) &&
 	echo treeH $treeH &&
 	git ls-tree $treeH
 '

 test_expect_success 'a/b vs a, plus c/d case test.' '
 	read_tree_u_must_succeed -u -m "$treeH" "$treeM" &&
 	git ls-files --stage | tee >treeMcheck.out &&
 	test_cmp treeM.out treeMcheck.out
 '

 test_expect_success '-m references the correct modified tree' '
 	echo >file-a &&
 	echo >file-b &&
 	git add file-a file-b &&
 	git commit -a -m "test for correct modified tree" &&
 	git branch initial-mod &&
 	echo b >file-b &&
 	git commit -a -m "B" &&
 	echo a >file-a &&
 	git add file-a &&
 	git ls-tree $(git write-tree) file-a >expect &&
 	read_tree_must_succeed -m HEAD initial-mod &&
 	git ls-tree $(git write-tree) file-a >actual &&
 	test_cmp expect actual
 '

 test_done
	#!/bin/sh
	#
	# Copyright (c) 2005 Junio C Hamano
	#

	test_description='Two way merge with read-tree -m $H $M

	This test tries two-way merge (aka fast-forward with carry forward).

	There is the head (called H) and another commit (called M), which is
	simply ahead of H. The index and the work tree contains a state that
	is derived from H, but may also have local changes. This test checks
	all the combinations described in the two-tree merge "carry forward"
	rules, found in <Documentation/git read-tree.txt>.

	In the test, these paths are used:
	bozbar - in H, stays in M, modified from bozbar to gnusto
	frotz - not in H added in M
	nitfol - in H, stays in M unmodified
	rezrov - in H, deleted in M
	yomin - not in H or M
	'
	. ./test-lib.sh
	. "$TEST_DIRECTORY"/lib-read-tree.sh

	read_tree_twoway () {
	git read-tree -m "$1" "$2" && git ls-files --stage
	}

	compare_change () {
	sed -n >current \
	-e '/^--- /d; /^+++ /d; /^@@ /d;' \
	-e 's/^\([-+][0-7][0-7][0-7][0-7][0-7][0-7]\) '"$OID_REGEX"' /\1 X /p' \
	"$1"
	test_cmp expected current
	}

	check_cache_at () {
	clean_if_empty=$(git diff-files -- "$1")
	case "$clean_if_empty" in
	'') echo "$1: clean" ;;
	?*) echo "$1: dirty" ;;
	esac
	case "$2,$clean_if_empty" in
	clean,) : ;;
	clean,?*) false ;;
	dirty,) false ;;
	dirty,?*) : ;;
	esac
	}

	cat >bozbar-old <<\EOF
	This is a sample file used in two-way fast-forward merge
	tests. Its second line ends with a magic word bozbar
	which will be modified by the merged head to gnusto.
	It has some extra lines so that external tools can
	successfully merge independent changes made to later
	lines (such as this one), avoiding line conflicts.
	EOF

	sed -e 's/bozbar/gnusto (earlier bozbar)/' bozbar-old >bozbar-new

	test_expect_success 'setup' '
	echo frotz >frotz &&
	echo nitfol >nitfol &&
	cat bozbar-old >bozbar &&
	echo rezrov >rezrov &&
	echo yomin >yomin &&
	git update-index --add nitfol bozbar rezrov &&
	treeH=$(git write-tree) &&
	echo treeH $treeH &&
	git ls-tree $treeH &&

	cat bozbar-new >bozbar &&
	git update-index --add frotz bozbar --force-remove rezrov &&
	git ls-files --stage >M.out &&
	treeM=$(git write-tree) &&
	echo treeM $treeM &&
	git ls-tree $treeM &&
	git diff-tree $treeH $treeM
	'

	test_expect_success '1, 2, 3 - no carry forward' '
	rm -f .git/index &&
	read_tree_twoway $treeH $treeM &&
	git ls-files --stage >1-3.out &&
	test_cmp M.out 1-3.out &&
	check_cache_at bozbar dirty &&
	check_cache_at frotz dirty &&
	check_cache_at nitfol dirty
	'
	echo '+100644 X 0 yomin' >expected

	test_expect_success '4 - carry forward local addition.' '
	rm -f .git/index &&
	read_tree_must_succeed $treeH &&
	git checkout-index -u -f -q -a &&
	git update-index --add yomin &&
	read_tree_twoway $treeH $treeM &&
	git ls-files --stage >4.out &&
	test_must_fail git diff --no-index M.out 4.out >4diff.out &&
	compare_change 4diff.out expected &&
	check_cache_at yomin clean
	'

	test_expect_success '5 - carry forward local addition.' '
	rm -f .git/index &&
	read_tree_must_succeed $treeH &&
	git checkout-index -u -f -q -a &&
	echo yomin >yomin &&
	git update-index --add yomin &&
	echo yomin yomin >yomin &&
	read_tree_twoway $treeH $treeM &&
	git ls-files --stage >5.out &&
	test_must_fail git diff --no-index M.out 5.out >5diff.out &&
	compare_change 5diff.out expected &&
	check_cache_at yomin dirty
	'

	test_expect_success '6 - local addition already has the same.' '
	rm -f .git/index &&
	read_tree_must_succeed $treeH &&
	git checkout-index -u -f -q -a &&
	git update-index --add frotz &&
	read_tree_twoway $treeH $treeM &&
	git ls-files --stage >6.out &&
	test_cmp M.out 6.out &&
	check_cache_at frotz clean
	'

	test_expect_success '7 - local addition already has the same.' '
	rm -f .git/index &&
	read_tree_must_succeed $treeH &&
	git checkout-index -u -f -q -a &&
	echo frotz >frotz &&
	git update-index --add frotz &&
	echo frotz frotz >frotz &&
	read_tree_twoway $treeH $treeM &&
	git ls-files --stage >7.out &&
	test_cmp M.out 7.out &&
	check_cache_at frotz dirty
	'

	test_expect_success '8 - conflicting addition.' '
	rm -f .git/index &&
	read_tree_must_succeed $treeH &&
	git checkout-index -u -f -q -a &&
	echo frotz frotz >frotz &&
	git update-index --add frotz &&
	if read_tree_twoway $treeH $treeM; then false; else :; fi
	'

	test_expect_success '9 - conflicting addition.' '
	rm -f .git/index &&
	read_tree_must_succeed $treeH &&
	git checkout-index -u -f -q -a &&
	echo frotz frotz >frotz &&
	git update-index --add frotz &&
	echo frotz >frotz &&
	if read_tree_twoway $treeH $treeM; then false; else :; fi
	'

	test_expect_success '10 - path removed.' '
	rm -f .git/index &&
	read_tree_must_succeed $treeH &&
	git checkout-index -u -f -q -a &&
	echo rezrov >rezrov &&
	git update-index --add rezrov &&
	read_tree_twoway $treeH $treeM &&
	git ls-files --stage >10.out &&
	test_cmp M.out 10.out
	'

	test_expect_success '11 - dirty path removed.' '
	rm -f .git/index &&
	read_tree_must_succeed $treeH &&
	git checkout-index -u -f -q -a &&
	echo rezrov >rezrov &&
	git update-index --add rezrov &&
	echo rezrov rezrov >rezrov &&
	if read_tree_twoway $treeH $treeM; then false; else :; fi
	'

	test_expect_success '12 - unmatching local changes being removed.' '
	rm -f .git/index &&
	read_tree_must_succeed $treeH &&
	git checkout-index -u -f -q -a &&
	echo rezrov rezrov >rezrov &&
	git update-index --add rezrov &&
	if read_tree_twoway $treeH $treeM; then false; else :; fi
	'

	test_expect_success '13 - unmatching local changes being removed.' '
	rm -f .git/index &&
	read_tree_must_succeed $treeH &&
	git checkout-index -u -f -q -a &&
	echo rezrov rezrov >rezrov &&
	git update-index --add rezrov &&
	echo rezrov >rezrov &&
	if read_tree_twoway $treeH $treeM; then false; else :; fi
	'

	cat >expected <<EOF
	-100644 X 0 nitfol
	+100644 X 0 nitfol
	EOF

	test_expect_success '14 - unchanged in two heads.' '
	rm -f .git/index &&
	read_tree_must_succeed $treeH &&
	git checkout-index -u -f -q -a &&
	echo nitfol nitfol >nitfol &&
	git update-index --add nitfol &&
	read_tree_twoway $treeH $treeM &&
	git ls-files --stage >14.out &&
	test_must_fail git diff --no-index M.out 14.out >14diff.out &&
	compare_change 14diff.out expected &&
	check_cache_at nitfol clean
	'

	test_expect_success '15 - unchanged in two heads.' '
	rm -f .git/index &&
	read_tree_must_succeed $treeH &&
	git checkout-index -u -f -q -a &&
	echo nitfol nitfol >nitfol &&
	git update-index --add nitfol &&
	echo nitfol nitfol nitfol >nitfol &&
	read_tree_twoway $treeH $treeM &&
	git ls-files --stage >15.out &&
	test_must_fail git diff --no-index M.out 15.out >15diff.out &&
	compare_change 15diff.out expected &&
	check_cache_at nitfol dirty
	'

	test_expect_success '16 - conflicting local change.' '
	rm -f .git/index &&
	read_tree_must_succeed $treeH &&
	git checkout-index -u -f -q -a &&
	echo bozbar bozbar >bozbar &&
	git update-index --add bozbar &&
	if read_tree_twoway $treeH $treeM; then false; else :; fi
	'

	test_expect_success '17 - conflicting local change.' '
	rm -f .git/index &&
	read_tree_must_succeed $treeH &&
	git checkout-index -u -f -q -a &&
	echo bozbar bozbar >bozbar &&
	git update-index --add bozbar &&
	echo bozbar bozbar bozbar >bozbar &&
	if read_tree_twoway $treeH $treeM; then false; else :; fi
	'

	test_expect_success '18 - local change already having a good result.' '
	rm -f .git/index &&
	read_tree_must_succeed $treeH &&
	git checkout-index -u -f -q -a &&
	cat bozbar-new >bozbar &&
	git update-index --add bozbar &&
	read_tree_twoway $treeH $treeM &&
	git ls-files --stage >18.out &&
	test_cmp M.out 18.out &&
	check_cache_at bozbar clean
	'

	test_expect_success '19 - local change already having a good result, further modified.' '
	rm -f .git/index &&
	read_tree_must_succeed $treeH &&
	git checkout-index -u -f -q -a &&
	cat bozbar-new >bozbar &&
	git update-index --add bozbar &&
	echo gnusto gnusto >bozbar &&
	read_tree_twoway $treeH $treeM &&
	git ls-files --stage >19.out &&
	test_cmp M.out 19.out &&
	check_cache_at bozbar dirty
	'

	test_expect_success '20 - no local change, use new tree.' '
	rm -f .git/index &&
	read_tree_must_succeed $treeH &&
	git checkout-index -u -f -q -a &&
	cat bozbar-old >bozbar &&
	git update-index --add bozbar &&
	read_tree_twoway $treeH $treeM &&
	git ls-files --stage >20.out &&
	test_cmp M.out 20.out &&
	check_cache_at bozbar dirty
	'

	test_expect_success '21 - no local change, dirty cache.' '
	rm -f .git/index &&
	read_tree_must_succeed $treeH &&
	git checkout-index -u -f -q -a &&
	cat bozbar-old >bozbar &&
	git update-index --add bozbar &&
	echo gnusto gnusto >bozbar &&
	if read_tree_twoway $treeH $treeM; then false; else :; fi
	'

	# This fails with straight two-way fast-forward.
	test_expect_success '22 - local change cache updated.' '
	rm -f .git/index &&
	read_tree_must_succeed $treeH &&
	git checkout-index -u -f -q -a &&
	sed -e "s/such as/SUCH AS/" bozbar-old >bozbar &&
	git update-index --add bozbar &&
	if read_tree_twoway $treeH $treeM; then false; else :; fi
	'

	# Also make sure we did not break DF vs DF/DF case.
	test_expect_success 'DF vs DF/DF case setup.' '
	rm -f .git/index &&
	echo DF >DF &&
	git update-index --add DF &&
	treeDF=$(git write-tree) &&
	echo treeDF $treeDF &&
	git ls-tree $treeDF &&

	rm -f DF &&
	mkdir DF &&
	echo DF/DF >DF/DF &&
	git update-index --add --remove DF DF/DF &&
	treeDFDF=$(git write-tree) &&
	echo treeDFDF $treeDFDF &&
	git ls-tree $treeDFDF &&
	git ls-files --stage >DFDF.out
	'

	test_expect_success 'DF vs DF/DF case test.' '
	rm -f .git/index &&
	rm -fr DF &&
	echo DF >DF &&
	git update-index --add DF &&
	read_tree_twoway $treeDF $treeDFDF &&
	git ls-files --stage >DFDFcheck.out &&
	test_cmp DFDF.out DFDFcheck.out &&
	check_cache_at DF/DF dirty &&
	:
	'

	test_expect_success 'a/b (untracked) vs a case setup.' '
	rm -f .git/index &&
	: >a &&
	git update-index --add a &&
	treeM=$(git write-tree) &&
	echo treeM $treeM &&
	git ls-tree $treeM &&
	git ls-files --stage >treeM.out &&

	rm -f a &&
	git update-index --remove a &&
	mkdir a &&
	: >a/b &&
	treeH=$(git write-tree) &&
	echo treeH $treeH &&
	git ls-tree $treeH
	'

	test_expect_success 'a/b (untracked) vs a, plus c/d case test.' '
	read_tree_u_must_fail -u -m "$treeH" "$treeM" &&
	git ls-files --stage &&
	test -f a/b
	'

	test_expect_success 'read-tree supports the super-prefix' '
	cat <<-EOF >expect &&
	error: Updating '\''fictional/a'\'' would lose untracked files in it
	EOF
	test_must_fail git --super-prefix fictional/ read-tree -u -m "$treeH" "$treeM" 2>actual &&
	test_cmp expect actual
	'

	test_expect_success 'a/b vs a, plus c/d case setup.' '
	rm -f .git/index &&
	rm -fr a &&
	: >a &&
	mkdir c &&
	: >c/d &&
	git update-index --add a c/d &&
	treeM=$(git write-tree) &&
	echo treeM $treeM &&
	git ls-tree $treeM &&
	git ls-files --stage >treeM.out &&

	rm -f a &&
	mkdir a &&
	: >a/b &&
	git update-index --add --remove a a/b &&
	treeH=$(git write-tree) &&
	echo treeH $treeH &&
	git ls-tree $treeH
	'

	test_expect_success 'a/b vs a, plus c/d case test.' '
	read_tree_u_must_succeed -u -m "$treeH" "$treeM" &&
	git ls-files --stage \| tee >treeMcheck.out &&
	test_cmp treeM.out treeMcheck.out
	'

	test_expect_success '-m references the correct modified tree' '
	echo >file-a &&
	echo >file-b &&
	git add file-a file-b &&
	git commit -a -m "test for correct modified tree" &&
	git branch initial-mod &&
	echo b >file-b &&
	git commit -a -m "B" &&
	echo a >file-a &&
	git add file-a &&
	git ls-tree $(git write-tree) file-a >expect &&
	read_tree_must_succeed -m HEAD initial-mod &&
	git ls-tree $(git write-tree) file-a >actual &&
	test_cmp expect actual
	'

	test_done