: Included from t1000-read-tree-m-3way.sh and others
# Original tree.
mkdir Z
for a in N D M
do
    for b in N D M
    do
        p=$a$b
	echo This is $p from the original tree. >$p
	echo This is Z/$p from the original tree. >Z/$p
	test_expect_success \
	    "adding test file $p and Z/$p" \
	    'git update-index --add $p &&
	    git update-index --add Z/$p'
    done
done
echo This is SS from the original tree. >SS
test_expect_success \
    'adding test file SS' \
    'git update-index --add SS'
cat >TT <<\EOF
This is a trivial merge sample text.
Branch A is expected to upcase this word, here.
There are some filler lines to avoid diff context
conflicts here,
like this one,
and this one,
and this one is yet another one of them.
At the very end, here comes another line, that is
the word, expected to be upcased by Branch B.
This concludes the trivial merge sample file.
EOF
test_expect_success \
    'adding test file TT' \
    'git update-index --add TT'
test_expect_success \
    'prepare initial tree' \
    'tree_O=$(git write-tree)'

################################################################
# Branch A and B makes the changes according to the above matrix.

################################################################
# Branch A

to_remove=$(echo D? Z/D?)
rm -f $to_remove
test_expect_success \
    'change in branch A (removal)' \
    'git update-index --remove $to_remove'

for p in M? Z/M?
do
    echo This is modified $p in the branch A. >$p
    test_expect_success \
	'change in branch A (modification)' \
        "git update-index $p"
done

for p in AN AA Z/AN Z/AA
do
    echo This is added $p in the branch A. >$p
    test_expect_success \
	'change in branch A (addition)' \
	"git update-index --add $p"
done

echo This is SS from the modified tree. >SS
echo This is LL from the modified tree. >LL
test_expect_success \
    'change in branch A (addition)' \
    'git update-index --add LL &&
     git update-index SS'
mv TT TT-
sed -e '/Branch A/s/word/WORD/g' <TT- >TT
rm -f TT-
test_expect_success \
    'change in branch A (edit)' \
    'git update-index TT'

mkdir DF
echo Branch A makes a file at DF/DF, creating a directory DF. >DF/DF
test_expect_success \
    'change in branch A (change file to directory)' \
    'git update-index --add DF/DF'

test_expect_success \
    'recording branch A tree' \
    'tree_A=$(git write-tree)'

################################################################
# Branch B
# Start from O

rm -rf [NDMASLT][NDMASLT] Z DF
mkdir Z
test_expect_success \
    'reading original tree and checking out' \
    'git read-tree $tree_O &&
     git checkout-index -a'

to_remove=$(echo ?D Z/?D)
rm -f $to_remove
test_expect_success \
    'change in branch B (removal)' \
    "git update-index --remove $to_remove"

for p in ?M Z/?M
do
    echo This is modified $p in the branch B. >$p
    test_expect_success \
	'change in branch B (modification)' \
	"git update-index $p"
done

for p in NA AA Z/NA Z/AA
do
    echo This is added $p in the branch B. >$p
    test_expect_success \
	'change in branch B (addition)' \
	"git update-index --add $p"
done
echo This is SS from the modified tree. >SS
echo This is LL from the modified tree. >LL
test_expect_success \
    'change in branch B (addition and modification)' \
    'git update-index --add LL &&
     git update-index SS'
mv TT TT-
sed -e '/Branch B/s/word/WORD/g' <TT- >TT
rm -f TT-
test_expect_success \
    'change in branch B (modification)' \
    'git update-index TT'

echo Branch B makes a file at DF. >DF
test_expect_success \
    'change in branch B (addition of a file to conflict with directory)' \
    'git update-index --add DF'

test_expect_success \
    'recording branch B tree' \
    'tree_B=$(git write-tree)'

test_expect_success \
    'keep contents of 3 trees for easy access' \
    'rm -f .git/index &&
     git read-tree $tree_O &&
     mkdir .orig-O &&
     git checkout-index --prefix=.orig-O/ -f -q -a &&
     rm -f .git/index &&
     git read-tree $tree_A &&
     mkdir .orig-A &&
     git checkout-index --prefix=.orig-A/ -f -q -a &&
     rm -f .git/index &&
     git read-tree $tree_B &&
     mkdir .orig-B &&
     git checkout-index --prefix=.orig-B/ -f -q -a'