git/t/t6416-recursive-corner-case...

1887 lines
46 KiB
Bash
Executable File

#!/bin/sh
test_description='recursive merge corner cases involving criss-cross merges'
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
#
# L1 L2
# o---o
# / \ / \
# o X ?
# \ / \ /
# o---o
# R1 R2
#
test_expect_success 'setup basic criss-cross + rename with no modifications' '
git init basic-rename &&
(
cd basic-rename &&
ten="0 1 2 3 4 5 6 7 8 9" &&
printf "line %d in a sample file\n" $ten >one &&
printf "line %d in another sample file\n" $ten >two &&
git add one two &&
test_tick && git commit -m initial &&
git branch L1 &&
git checkout -b R1 &&
git mv one three &&
test_tick && git commit -m R1 &&
git checkout L1 &&
git mv two three &&
test_tick && git commit -m L1 &&
git checkout L1^0 &&
test_tick && git merge -s ours R1 &&
git tag L2 &&
git checkout R1^0 &&
test_tick && git merge -s ours L1 &&
git tag R2
)
'
test_expect_success 'merge simple rename+criss-cross with no modifications' '
(
cd basic-rename &&
git reset --hard &&
git checkout L2^0 &&
test_must_fail git merge -s recursive R2^0 &&
git ls-files -s >out &&
test_line_count = 5 out &&
git ls-files -u >out &&
test_line_count = 3 out &&
git ls-files -o >out &&
test_line_count = 1 out &&
git rev-parse >expect \
L2:three R2:three &&
git rev-parse >actual \
:2:three :3:three &&
test_cmp expect actual
)
'
#
# Same as before, but modify L1 slightly:
#
# L1m L2
# o---o
# / \ / \
# o X ?
# \ / \ /
# o---o
# R1 R2
#
test_expect_success 'setup criss-cross + rename merges with basic modification' '
git init rename-modify &&
(
cd rename-modify &&
ten="0 1 2 3 4 5 6 7 8 9" &&
printf "line %d in a sample file\n" $ten >one &&
printf "line %d in another sample file\n" $ten >two &&
git add one two &&
test_tick && git commit -m initial &&
git branch L1 &&
git checkout -b R1 &&
git mv one three &&
echo more >>two &&
git add two &&
test_tick && git commit -m R1 &&
git checkout L1 &&
git mv two three &&
test_tick && git commit -m L1 &&
git checkout L1^0 &&
test_tick && git merge -s ours R1 &&
git tag L2 &&
git checkout R1^0 &&
test_tick && git merge -s ours L1 &&
git tag R2
)
'
test_expect_success 'merge criss-cross + rename merges with basic modification' '
(
cd rename-modify &&
git checkout L2^0 &&
test_must_fail git merge -s recursive R2^0 &&
git ls-files -s >out &&
test_line_count = 5 out &&
git ls-files -u >out &&
test_line_count = 3 out &&
git ls-files -o >out &&
test_line_count = 1 out &&
git rev-parse >expect \
L2:three R2:three &&
git rev-parse >actual \
:2:three :3:three &&
test_cmp expect actual
)
'
#
# For the next test, we start with three commits in two lines of development
# which setup a rename/add conflict:
# Commit A: File 'a' exists
# Commit B: Rename 'a' -> 'new_a'
# Commit C: Modify 'a', create different 'new_a'
# Later, two different people merge and resolve differently:
# Commit D: Merge B & C, ignoring separately created 'new_a'
# Commit E: Merge B & C making use of some piece of secondary 'new_a'
# Finally, someone goes to merge D & E. Does git detect the conflict?
#
# B D
# o---o
# / \ / \
# A o X ? F
# \ / \ /
# o---o
# C E
#
test_expect_success 'setup differently handled merges of rename/add conflict' '
git init rename-add &&
(
cd rename-add &&
printf "0\n1\n2\n3\n4\n5\n6\n7\n8\n9\n" >a &&
git add a &&
test_tick && git commit -m A &&
git branch B &&
git checkout -b C &&
echo 10 >>a &&
test_write_lines 0 1 2 3 4 5 6 7 foobar >new_a &&
git add a new_a &&
test_tick && git commit -m C &&
git checkout B &&
git mv a new_a &&
test_tick && git commit -m B &&
git checkout B^0 &&
test_must_fail git merge C &&
git show :2:new_a >new_a &&
git add new_a &&
test_tick && git commit -m D &&
git tag D &&
git checkout C^0 &&
test_must_fail git merge B &&
test_write_lines 0 1 2 3 4 5 6 7 bad_merge >new_a &&
git add -u &&
test_tick && git commit -m E &&
git tag E
)
'
test_expect_success 'git detects differently handled merges conflict' '
(
cd rename-add &&
git checkout D^0 &&
test_must_fail git merge -s recursive E^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 &&
git cat-file -p C:new_a >ours &&
git cat-file -p C:a >theirs &&
>empty &&
test_must_fail git merge-file \
-L "Temporary merge branch 1" \
-L "" \
-L "Temporary merge branch 2" \
ours empty theirs &&
sed -e "s/^\([<=>]\)/\1\1\1/" ours >ours-tweaked &&
git hash-object ours-tweaked >expect &&
git rev-parse >>expect \
D:new_a E:new_a &&
git rev-parse >actual \
:1:new_a :2:new_a :3:new_a &&
test_cmp expect actual &&
# Test that the two-way merge in new_a is as expected
git cat-file -p D:new_a >ours &&
git cat-file -p E:new_a >theirs &&
>empty &&
test_must_fail git merge-file \
-L "HEAD" \
-L "" \
-L "E^0" \
ours empty theirs &&
sed -e "s/^\([<=>]\)/\1\1\1/" ours >expect &&
git hash-object new_a >actual &&
git hash-object ours >expect &&
test_cmp expect actual
)
'
# Repeat the above testcase with precisely the same setup, other than with
# the two merge bases having different orderings of commit timestamps so
# that they are reversed in the order they are provided to merge-recursive,
# so that we can improve code coverage.
test_expect_success 'git detects differently handled merges conflict, swapped' '
(
cd rename-add &&
# Difference #1: Do cleanup from previous testrun
git reset --hard &&
git clean -fdqx &&
# Difference #2: Change commit timestamps
btime=$(git log --no-walk --date=raw --format=%cd B | awk "{print \$1}") &&
ctime=$(git log --no-walk --date=raw --format=%cd C | awk "{print \$1}") &&
newctime=$(($btime+1)) &&
git fast-export --no-data --all | sed -e s/$ctime/$newctime/ | git fast-import --force --quiet &&
# End of most differences; rest is copy-paste of last test,
# other than swapping C:a and C:new_a due to order switch
git checkout D^0 &&
test_must_fail git merge -s recursive E^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 &&
git cat-file -p C:a >ours &&
git cat-file -p C:new_a >theirs &&
>empty &&
test_must_fail git merge-file \
-L "Temporary merge branch 1" \
-L "" \
-L "Temporary merge branch 2" \
ours empty theirs &&
sed -e "s/^\([<=>]\)/\1\1\1/" ours >ours-tweaked &&
git hash-object ours-tweaked >expect &&
git rev-parse >>expect \
D:new_a E:new_a &&
git rev-parse >actual \
:1:new_a :2:new_a :3:new_a &&
test_cmp expect actual &&
# Test that the two-way merge in new_a is as expected
git cat-file -p D:new_a >ours &&
git cat-file -p E:new_a >theirs &&
>empty &&
test_must_fail git merge-file \
-L "HEAD" \
-L "" \
-L "E^0" \
ours empty theirs &&
sed -e "s/^\([<=>]\)/\1\1\1/" ours >expect &&
git hash-object new_a >actual &&
git hash-object ours >expect &&
test_cmp expect actual
)
'
#
# criss-cross + modify/delete:
#
# B D
# o---o
# / \ / \
# A o X ? F
# \ / \ /
# o---o
# C E
#
# Commit A: file with contents 'A\n'
# Commit B: file with contents 'B\n'
# Commit C: file not present
# Commit D: file with contents 'B\n'
# Commit E: file not present
#
# Merging commits D & E should result in modify/delete conflict.
test_expect_success 'setup criss-cross + modify/delete resolved differently' '
git init modify-delete &&
(
cd modify-delete &&
echo A >file &&
git add file &&
test_tick &&
git commit -m A &&
git branch B &&
git checkout -b C &&
git rm file &&
test_tick &&
git commit -m C &&
git checkout B &&
echo B >file &&
git add file &&
test_tick &&
git commit -m B &&
git checkout B^0 &&
test_must_fail git merge C &&
echo B >file &&
git add file &&
test_tick &&
git commit -m D &&
git tag D &&
git checkout C^0 &&
test_must_fail git merge B &&
git rm file &&
test_tick &&
git commit -m E &&
git tag E
)
'
test_expect_success 'git detects conflict merging criss-cross+modify/delete' '
(
cd modify-delete &&
git checkout D^0 &&
test_must_fail git merge -s recursive E^0 &&
git ls-files -s >out &&
test_line_count = 2 out &&
git ls-files -u >out &&
test_line_count = 2 out &&
git rev-parse >expect \
main:file B:file &&
git rev-parse >actual \
:1:file :2:file &&
test_cmp expect actual
)
'
test_expect_success 'git detects conflict merging criss-cross+modify/delete, reverse direction' '
(
cd modify-delete &&
git reset --hard &&
git checkout E^0 &&
test_must_fail git merge -s recursive D^0 &&
git ls-files -s >out &&
test_line_count = 2 out &&
git ls-files -u >out &&
test_line_count = 2 out &&
git rev-parse >expect \
main:file B:file &&
git rev-parse >actual \
:1:file :3:file &&
test_cmp expect actual
)
'
# SORRY FOR THE SUPER LONG DESCRIPTION, BUT THIS NEXT ONE IS HAIRY
#
# criss-cross + d/f conflict via add/add:
# Commit A: Neither file 'a' nor directory 'a/' exists.
# Commit B: Introduce 'a'
# Commit C: Introduce 'a/file'
# Commit D1: Merge B & C, keeping 'a' and deleting 'a/'
# Commit E1: Merge B & C, deleting 'a' but keeping 'a/file'
#
# B D1 or D2
# o---o
# / \ / \
# A o X ? F
# \ / \ /
# o---o
# C E1 or E2 or E3
#
# I'll describe D2, E2, & E3 (which are alternatives for D1 & E1) more below...
#
# Merging D1 & E1 requires we first create a virtual merge base X from
# merging A & B in memory. There are several possibilities for the merge-base:
# 1: Keep both 'a' and 'a/file' (assuming crazy filesystem allowing a tree
# with a directory and file at same path): results in merge of D1 & E1
# being clean with both files deleted. Bad (no conflict detected).
# 2: Keep 'a' but not 'a/file': Merging D1 & E1 is clean and matches E1. Bad.
# 3: Keep 'a/file' but not 'a': Merging D1 & E1 is clean and matches D1. Bad.
# 4: Keep neither file: Merging D1 & E1 reports the D/F add/add conflict.
#
# So 4 sounds good for this case, but if we were to merge D1 & E3, where E3
# is defined as:
# Commit E3: Merge B & C, keeping modified a, and deleting a/
# then we'd get an add/add conflict for 'a', which seems suboptimal. A little
# creativity leads us to an alternate choice:
# 5: Keep 'a' as 'a~$UNIQUE' and a/file; results:
# Merge D1 & E1: rename/delete conflict for 'a'; a/file silently deleted
# Merge D1 & E3 is clean, as expected.
#
# So choice 5 at least provides some kind of conflict for the original case,
# and can merge cleanly as expected with D1 and E3. It also made things just
# slightly funny for merging D1 and E4, where E4 is defined as:
# Commit E4: Merge B & C, modifying 'a' and renaming to 'a2', and deleting 'a/'
# in this case, we'll get a rename/rename(1to2) conflict because a~$UNIQUE
# gets renamed to 'a' in D1 and to 'a2' in E4. But that's better than having
# two files (both 'a' and 'a2') sitting around without the user being notified
# that we could detect they were related and need to be merged. Also, choice
# 5 makes the handling of 'a/file' seem suboptimal. What if we were to merge
# D2 and E4, where D2 is:
# Commit D2: Merge B & C, renaming 'a'->'a2', keeping 'a/file'
# This would result in a clean merge with 'a2' having three-way merged
# contents (good), and deleting 'a/' (bad) -- it doesn't detect the
# conflict in how the different sides treated a/file differently.
# Continuing down the creative route:
# 6: Keep 'a' as 'a~$UNIQUE1' and keep 'a/' as 'a~$UNIQUE2/'; results:
# Merge D1 & E1: rename/delete conflict for 'a' and each path under 'a/'.
# Merge D1 & E3: clean, as expected.
# Merge D1 & E4: rename/rename(1to2) conflict on 'a' vs 'a2'.
# Merge D2 & E4: clean for 'a2', rename/delete for a/file
#
# Choice 6 could cause rename detection to take longer (providing more targets
# that need to be searched). Also, the conflict message for each path under
# 'a/' might be annoying unless we can detect it at the directory level, print
# it once, and then suppress it for individual filepaths underneath.
#
#
# As of time of writing, git uses choice 5. Directory rename detection and
# rename detection performance improvements might make choice 6 a desirable
# improvement. But we can at least document where we fall short for now...
#
#
# Historically, this testcase also used:
# Commit E2: Merge B & C, deleting 'a' but keeping slightly modified 'a/file'
# The merge of D1 & E2 is very similar to D1 & E1 -- it has similar issues for
# path 'a', but should always result in a modify/delete conflict for path
# 'a/file'. These tests ran the two merges
# D1 & E1
# D1 & E2
# in both directions, to check for directional issues with D/F conflict
# handling. Later we added
# D1 & E3
# D1 & E4
# D2 & E4
# for good measure, though we only ran those one way because we had pretty
# good confidence in merge-recursive's directional handling of D/F issues.
#
# Just to summarize all the intermediate merge commits:
# Commit D1: Merge B & C, keeping a and deleting a/
# Commit D2: Merge B & C, renaming a->a2, keeping a/file
# Commit E1: Merge B & C, deleting a but keeping a/file
# Commit E2: Merge B & C, deleting a but keeping slightly modified a/file
# Commit E3: Merge B & C, keeping modified a, and deleting a/
# Commit E4: Merge B & C, modifying 'a' and renaming to 'a2', and deleting 'a/'
#
test_expect_success 'setup differently handled merges of directory/file conflict' '
git init directory-file &&
(
cd directory-file &&
>ignore-me &&
git add ignore-me &&
test_tick &&
git commit -m A &&
git tag A &&
git branch B &&
git checkout -b C &&
mkdir a &&
test_write_lines a b c d e f g >a/file &&
git add a/file &&
test_tick &&
git commit -m C &&
git checkout B &&
test_write_lines 1 2 3 4 5 6 7 >a &&
git add a &&
test_tick &&
git commit -m B &&
git checkout B^0 &&
git merge -s ours -m D1 C^0 &&
git tag D1 &&
git checkout B^0 &&
test_must_fail git merge C^0 &&
if test "$GIT_TEST_MERGE_ALGORITHM" = ort
then
git rm -rf a/ &&
git rm a~HEAD
else
git clean -fd &&
git rm -rf a/ &&
git rm a
fi &&
git cat-file -p B:a >a2 &&
git add a2 &&
git commit -m D2 &&
git tag D2 &&
git checkout C^0 &&
git merge -s ours -m E1 B^0 &&
git tag E1 &&
git checkout C^0 &&
git merge -s ours -m E2 B^0 &&
test_write_lines a b c d e f g h >a/file &&
git add a/file &&
git commit --amend -C HEAD &&
git tag E2 &&
git checkout C^0 &&
test_must_fail git merge B^0 &&
if test "$GIT_TEST_MERGE_ALGORITHM" = ort
then
git rm a~B^0
else
git clean -fd
fi &&
git rm -rf a/ &&
test_write_lines 1 2 3 4 5 6 7 8 >a &&
git add a &&
git commit -m E3 &&
git tag E3 &&
git checkout C^0 &&
test_must_fail git merge B^0 &&
if test "$GIT_TEST_MERGE_ALGORITHM" = ort
then
git rm -rf a/ &&
git rm a~B^0
else
git clean -fd &&
git rm -rf a/ &&
git rm a
fi &&
test_write_lines 1 2 3 4 5 6 7 8 >a2 &&
git add a2 &&
git commit -m E4 &&
git tag E4
)
'
test_expect_success 'merge of D1 & E1 fails but has appropriate contents' '
test_when_finished "git -C directory-file reset --hard" &&
test_when_finished "git -C directory-file clean -fdqx" &&
(
cd directory-file &&
git checkout D1^0 &&
test_must_fail git merge -s recursive E1^0 &&
if test "$GIT_TEST_MERGE_ALGORITHM" = ort
then
git ls-files -s >out &&
test_line_count = 3 out &&
git ls-files -u >out &&
test_line_count = 2 out &&
git ls-files -o >out &&
test_line_count = 1 out &&
git rev-parse >expect \
A:ignore-me B:a D1:a &&
git rev-parse >actual \
:0:ignore-me :1:a :2:a &&
test_cmp expect actual
else
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 &&
test_line_count = 1 out &&
git rev-parse >expect \
A:ignore-me B:a &&
git rev-parse >actual \
:0:ignore-me :2:a &&
test_cmp expect actual
fi
)
'
test_expect_success 'merge of E1 & D1 fails but has appropriate contents' '
test_when_finished "git -C directory-file reset --hard" &&
test_when_finished "git -C directory-file clean -fdqx" &&
(
cd directory-file &&
git checkout E1^0 &&
test_must_fail git merge -s recursive D1^0 &&
if test "$GIT_TEST_MERGE_ALGORITHM" = ort
then
git ls-files -s >out &&
test_line_count = 3 out &&
git ls-files -u >out &&
test_line_count = 2 out &&
git ls-files -o >out &&
test_line_count = 1 out &&
git rev-parse >expect \
A:ignore-me B:a D1:a &&
git rev-parse >actual \
:0:ignore-me :1:a :3:a &&
test_cmp expect actual
else
git ls-files -s >out &&
test_line_count = 2 out &&
git ls-files -u >out &&
test_line_count = 1 out &&
git ls-files -o >out &&
test_line_count = 1 out &&
git rev-parse >expect \
A:ignore-me B:a &&
git rev-parse >actual \
:0:ignore-me :3:a &&
test_cmp expect actual
fi
)
'
test_expect_success 'merge of D1 & E2 fails but has appropriate contents' '
test_when_finished "git -C directory-file reset --hard" &&
test_when_finished "git -C directory-file clean -fdqx" &&
(
cd directory-file &&
git checkout D1^0 &&
test_must_fail git merge -s recursive E2^0 &&
if test "$GIT_TEST_MERGE_ALGORITHM" = ort
then
git ls-files -s >out &&
test_line_count = 5 out &&
git ls-files -u >out &&
test_line_count = 4 out &&
git ls-files -o >out &&
test_line_count = 1 out &&
git rev-parse >expect \
B:a D1:a E2:a/file C:a/file A:ignore-me &&
git rev-parse >actual \
:1:a~HEAD :2:a~HEAD :3:a/file :1:a/file :0:ignore-me
else
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 &&
test_line_count = 2 out &&
git rev-parse >expect \
B:a E2:a/file C:a/file A:ignore-me &&
git rev-parse >actual \
:2:a :3:a/file :1:a/file :0:ignore-me
fi &&
test_cmp expect actual &&
test_path_is_file a~HEAD
)
'
test_expect_success 'merge of E2 & D1 fails but has appropriate contents' '
test_when_finished "git -C directory-file reset --hard" &&
test_when_finished "git -C directory-file clean -fdqx" &&
(
cd directory-file &&
git checkout E2^0 &&
test_must_fail git merge -s recursive D1^0 &&
if test "$GIT_TEST_MERGE_ALGORITHM" = ort
then
git ls-files -s >out &&
test_line_count = 5 out &&
git ls-files -u >out &&
test_line_count = 4 out &&
git ls-files -o >out &&
test_line_count = 1 out &&
git rev-parse >expect \
B:a D1:a E2:a/file C:a/file A:ignore-me &&
git rev-parse >actual \
:1:a~D1^0 :3:a~D1^0 :2:a/file :1:a/file :0:ignore-me
else
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 &&
test_line_count = 2 out &&
git rev-parse >expect \
B:a E2:a/file C:a/file A:ignore-me &&
git rev-parse >actual \
:3:a :2:a/file :1:a/file :0:ignore-me
fi &&
test_cmp expect actual &&
test_path_is_file a~D1^0
)
'
test_expect_success 'merge of D1 & E3 succeeds' '
test_when_finished "git -C directory-file reset --hard" &&
test_when_finished "git -C directory-file clean -fdqx" &&
(
cd directory-file &&
git checkout D1^0 &&
git merge -s recursive E3^0 &&
git ls-files -s >out &&
test_line_count = 2 out &&
git ls-files -u >out &&
test_line_count = 0 out &&
git ls-files -o >out &&
test_line_count = 1 out &&
git rev-parse >expect \
A:ignore-me E3:a &&
git rev-parse >actual \
:0:ignore-me :0:a &&
test_cmp expect actual
)
'
test_expect_merge_algorithm failure success 'merge of D1 & E4 puts merge of a and a2 in both a and a2' '
test_when_finished "git -C directory-file reset --hard" &&
test_when_finished "git -C directory-file clean -fdqx" &&
(
cd directory-file &&
git checkout D1^0 &&
test_must_fail git merge -s recursive E4^0 &&
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 &&
test_line_count = 1 out &&
git rev-parse >expect \
A:ignore-me B:a E4:a2 E4:a2 &&
git rev-parse >actual \
:0:ignore-me :1:a~Temporary\ merge\ branch\ 2 :2:a :3:a2 &&
test_cmp expect actual
)
'
test_expect_failure 'merge of D2 & E4 merges a2s & reports conflict for a/file' '
test_when_finished "git -C directory-file reset --hard" &&
test_when_finished "git -C directory-file clean -fdqx" &&
(
cd directory-file &&
git checkout D2^0 &&
test_must_fail git merge -s recursive E4^0 &&
git ls-files -s >out &&
test_line_count = 3 out &&
git ls-files -u >out &&
test_line_count = 1 out &&
git ls-files -o >out &&
test_line_count = 1 out &&
git rev-parse >expect \
A:ignore-me E4:a2 D2:a/file &&
git rev-parse >actual \
:0:ignore-me :0:a2 :2:a/file &&
test_cmp expect actual
)
'
#
# criss-cross with rename/rename(1to2)/modify followed by
# rename/rename(2to1)/modify:
#
# B D
# o---o
# / \ / \
# A o X ? F
# \ / \ /
# o---o
# C E
#
# Commit A: new file: a
# Commit B: rename a->b, modifying by adding a line
# Commit C: rename a->c
# Commit D: merge B&C, resolving conflict by keeping contents in newname
# Commit E: merge B&C, resolving conflict similar to D but adding another line
#
# There is a conflict merging B & C, but one of filename not of file
# content. Whoever created D and E chose specific resolutions for that
# conflict resolution. Now, since: (1) there is no content conflict
# merging B & C, (2) D does not modify that merged content further, and (3)
# both D & E resolve the name conflict in the same way, the modification to
# newname in E should not cause any conflicts when it is merged with D.
# (Note that this can be accomplished by having the virtual merge base have
# the merged contents of b and c stored in a file named a, which seems like
# the most logical choice anyway.)
#
# Comment from Junio: I do not necessarily agree with the choice "a", but
# it feels sound to say "B and C do not agree what the final pathname
# should be, but we know this content was derived from the common A:a so we
# use one path whose name is arbitrary in the virtual merge base X between
# D and E" and then further let the rename detection to notice that that
# arbitrary path gets renamed between X-D to "newname" and X-E also to
# "newname" to resolve it as both sides renaming it to the same new
# name. It is akin to what we do at the content level, i.e. "B and C do not
# agree what the final contents should be, so we leave the conflict marker
# but that may cancel out at the final merge stage".
test_expect_success 'setup rename/rename(1to2)/modify followed by what looks like rename/rename(2to1)/modify' '
git init rename-squared-squared &&
(
cd rename-squared-squared &&
printf "1\n2\n3\n4\n5\n6\n" >a &&
git add a &&
git commit -m A &&
git tag A &&
git checkout -b B A &&
git mv a b &&
echo 7 >>b &&
git add -u &&
git commit -m B &&
git checkout -b C A &&
git mv a c &&
git commit -m C &&
git checkout -q B^0 &&
git merge --no-commit -s ours C^0 &&
git mv b newname &&
git commit -m "Merge commit C^0 into HEAD" &&
git tag D &&
git checkout -q C^0 &&
git merge --no-commit -s ours B^0 &&
git mv c newname &&
printf "7\n8\n" >>newname &&
git add -u &&
git commit -m "Merge commit B^0 into HEAD" &&
git tag E
)
'
test_expect_success 'handle rename/rename(1to2)/modify followed by what looks like rename/rename(2to1)/modify' '
(
cd rename-squared-squared &&
git checkout D^0 &&
git merge -s recursive E^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 &&
test $(git rev-parse HEAD:newname) = $(git rev-parse E:newname)
)
'
#
# criss-cross with rename/rename(1to2)/add-source + resolvable modify/modify:
#
# B D
# o---o
# / \ / \
# A o X ? F
# \ / \ /
# o---o
# C E
#
# Commit A: new file: a
# Commit B: rename a->b
# Commit C: rename a->c, add different a
# Commit D: merge B&C, keeping b&c and (new) a modified at beginning
# Commit E: merge B&C, keeping b&c and (new) a modified at end
#
# Merging commits D & E should result in no conflict; doing so correctly
# requires getting the virtual merge base (from merging B&C) right, handling
# renaming carefully (both in the virtual merge base and later), and getting
# content merge handled.
test_expect_success 'setup criss-cross + rename/rename/add-source + modify/modify' '
git init rename-rename-add-source &&
(
cd rename-rename-add-source &&
printf "lots\nof\nwords\nand\ncontent\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 &&
printf "2\n3\n4\n5\n6\n7\n" >a &&
git add a &&
git commit -m C &&
git checkout B^0 &&
git merge --no-commit -s ours C^0 &&
git checkout C -- a c &&
mv a old_a &&
echo 1 >a &&
cat old_a >>a &&
rm old_a &&
git add -u &&
git commit -m "Merge commit C^0 into HEAD" &&
git tag D &&
git checkout C^0 &&
git merge --no-commit -s ours B^0 &&
git checkout B -- b &&
echo 8 >>a &&
git add -u &&
git commit -m "Merge commit B^0 into HEAD" &&
git tag E
)
'
test_expect_failure 'detect rename/rename/add-source for virtual merge-base' '
(
cd rename-rename-add-source &&
git checkout D^0 &&
git merge -s recursive E^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 &&
printf "1\n2\n3\n4\n5\n6\n7\n8\n" >correct &&
git rev-parse >expect \
A:a A:a \
correct &&
git rev-parse >actual \
:0:b :0:c &&
git hash-object >>actual \
a &&
test_cmp expect actual
)
'
#
# criss-cross with rename/rename(1to2)/add-dest + simple modify:
#
# B D
# o---o
# / \ / \
# A o X ? F
# \ / \ /
# o---o
# C E
#
# Commit A: new file: a
# Commit B: rename a->b, add c
# Commit C: rename a->c
# Commit D: merge B&C, keeping A:a and B:c
# Commit E: merge B&C, keeping A:a and slightly modified c from B
#
# Merging commits D & E should result in no conflict. The virtual merge
# base of B & C needs to not delete B:c for that to work, though...
test_expect_success 'setup criss-cross+rename/rename/add-dest + simple modify' '
git init rename-rename-add-dest &&
(
cd rename-rename-add-dest &&
>a &&
git add a &&
git commit -m A &&
git tag A &&
git checkout -b B A &&
git mv a b &&
printf "1\n2\n3\n4\n5\n6\n7\n" >c &&
git add c &&
git commit -m B &&
git checkout -b C A &&
git mv a c &&
git commit -m C &&
git checkout B^0 &&
git merge --no-commit -s ours C^0 &&
git mv b a &&
git commit -m "D is like B but renames b back to a" &&
git tag D &&
git checkout B^0 &&
git merge --no-commit -s ours C^0 &&
git mv b a &&
echo 8 >>c &&
git add c &&
git commit -m "E like D but has mod in c" &&
git tag E
)
'
test_expect_success 'virtual merge base handles rename/rename(1to2)/add-dest' '
(
cd rename-rename-add-dest &&
git checkout D^0 &&
git merge -s recursive E^0 &&
git ls-files -s >out &&
test_line_count = 2 out &&
git ls-files -u >out &&
test_line_count = 0 out &&
git ls-files -o >out &&
test_line_count = 1 out &&
git rev-parse >expect \
A:a E:c &&
git rev-parse >actual \
:0:a :0:c &&
test_cmp expect actual
)
'
#
# criss-cross with modify/modify on a symlink:
#
# B D
# o---o
# / \ / \
# A o X ? F
# \ / \ /
# o---o
# C E
#
# Commit A: simple simlink fickle->lagoon
# Commit B: redirect fickle->disneyland
# Commit C: redirect fickle->home
# Commit D: merge B&C, resolving in favor of B
# Commit E: merge B&C, resolving in favor of C
#
# This is an obvious modify/modify conflict for the symlink 'fickle'. Can
# git detect it?
test_expect_success 'setup symlink modify/modify' '
git init symlink-modify-modify &&
(
cd symlink-modify-modify &&
test_ln_s_add lagoon fickle &&
git commit -m A &&
git tag A &&
git checkout -b B A &&
git rm fickle &&
test_ln_s_add disneyland fickle &&
git commit -m B &&
git checkout -b C A &&
git rm fickle &&
test_ln_s_add home fickle &&
git add fickle &&
git commit -m C &&
git checkout -q B^0 &&
git merge -s ours -m D C^0 &&
git tag D &&
git checkout -q C^0 &&
git merge -s ours -m E B^0 &&
git tag E
)
'
test_expect_merge_algorithm failure success 'check symlink modify/modify' '
(
cd symlink-modify-modify &&
git checkout D^0 &&
test_must_fail git merge -s recursive E^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
)
'
#
# criss-cross with add/add of a symlink:
#
# B D
# o---o
# / \ / \
# A o X ? F
# \ / \ /
# o---o
# C E
#
# Commit A: No symlink or path exists yet
# Commit B: set up symlink: fickle->disneyland
# Commit C: set up symlink: fickle->home
# Commit D: merge B&C, resolving in favor of B
# Commit E: merge B&C, resolving in favor of C
#
# This is an obvious add/add conflict for the symlink 'fickle'. Can
# git detect it?
test_expect_success 'setup symlink add/add' '
git init symlink-add-add &&
(
cd symlink-add-add &&
touch ignoreme &&
git add ignoreme &&
git commit -m A &&
git tag A &&
git checkout -b B A &&
test_ln_s_add disneyland fickle &&
git commit -m B &&
git checkout -b C A &&
test_ln_s_add home fickle &&
git add fickle &&
git commit -m C &&
git checkout -q B^0 &&
git merge -s ours -m D C^0 &&
git tag D &&
git checkout -q C^0 &&
git merge -s ours -m E B^0 &&
git tag E
)
'
test_expect_merge_algorithm failure success 'check symlink add/add' '
(
cd symlink-add-add &&
git checkout D^0 &&
test_must_fail git merge -s recursive E^0 &&
git ls-files -s >out &&
test_line_count = 3 out &&
git ls-files -u >out &&
test_line_count = 2 out &&
git ls-files -o >out &&
test_line_count = 1 out
)
'
#
# criss-cross with modify/modify on a submodule:
#
# B D
# o---o
# / \ / \
# A o X ? F
# \ / \ /
# o---o
# C E
#
# Commit A: simple submodule repo
# Commit B: update repo
# Commit C: update repo differently
# Commit D: merge B&C, resolving in favor of B
# Commit E: merge B&C, resolving in favor of C
#
# This is an obvious modify/modify conflict for the submodule 'repo'. Can
# git detect it?
test_expect_success 'setup submodule modify/modify' '
git init submodule-modify-modify &&
(
cd submodule-modify-modify &&
git init submod &&
(
cd submod &&
touch file-A &&
git add file-A &&
git commit -m A &&
git tag A &&
git checkout -b B A &&
touch file-B &&
git add file-B &&
git commit -m B &&
git tag B &&
git checkout -b C A &&
touch file-C &&
git add file-C &&
git commit -m C &&
git tag C
) &&
git -C submod reset --hard A &&
git add submod &&
git commit -m A &&
git tag A &&
git checkout -b B A &&
git -C submod reset --hard B &&
git add submod &&
git commit -m B &&
git checkout -b C A &&
git -C submod reset --hard C &&
git add submod &&
git commit -m C &&
git checkout -q B^0 &&
git merge -s ours -m D C^0 &&
git tag D &&
git checkout -q C^0 &&
git merge -s ours -m E B^0 &&
git tag E
)
'
test_expect_merge_algorithm failure success 'check submodule modify/modify' '
(
cd submodule-modify-modify &&
git checkout D^0 &&
test_must_fail git merge -s recursive E^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
)
'
#
# criss-cross with add/add on a submodule:
#
# B D
# o---o
# / \ / \
# A o X ? F
# \ / \ /
# o---o
# C E
#
# Commit A: nothing of note
# Commit B: introduce submodule repo
# Commit C: introduce submodule repo at different commit
# Commit D: merge B&C, resolving in favor of B
# Commit E: merge B&C, resolving in favor of C
#
# This is an obvious add/add conflict for the submodule 'repo'. Can
# git detect it?
test_expect_success 'setup submodule add/add' '
git init submodule-add-add &&
(
cd submodule-add-add &&
git init submod &&
(
cd submod &&
touch file-A &&
git add file-A &&
git commit -m A &&
git tag A &&
git checkout -b B A &&
touch file-B &&
git add file-B &&
git commit -m B &&
git tag B &&
git checkout -b C A &&
touch file-C &&
git add file-C &&
git commit -m C &&
git tag C
) &&
touch irrelevant-file &&
git add irrelevant-file &&
git commit -m A &&
git tag A &&
git checkout -b B A &&
git -C submod reset --hard B &&
git add submod &&
git commit -m B &&
git checkout -b C A &&
git -C submod reset --hard C &&
git add submod &&
git commit -m C &&
git checkout -q B^0 &&
git merge -s ours -m D C^0 &&
git tag D &&
git checkout -q C^0 &&
git merge -s ours -m E B^0 &&
git tag E
)
'
test_expect_merge_algorithm failure success 'check submodule add/add' '
(
cd submodule-add-add &&
git checkout D^0 &&
test_must_fail git merge -s recursive E^0 &&
git ls-files -s >out &&
test_line_count = 3 out &&
git ls-files -u >out &&
test_line_count = 2 out &&
git ls-files -o >out &&
test_line_count = 1 out
)
'
#
# criss-cross with conflicting entry types:
#
# B D
# o---o
# / \ / \
# A o X ? F
# \ / \ /
# o---o
# C E
#
# Commit A: nothing of note
# Commit B: introduce submodule 'path'
# Commit C: introduce symlink 'path'
# Commit D: merge B&C, resolving in favor of B
# Commit E: merge B&C, resolving in favor of C
#
# This is an obvious add/add conflict for 'path'. Can git detect it?
test_expect_success 'setup conflicting entry types (submodule vs symlink)' '
git init submodule-symlink-add-add &&
(
cd submodule-symlink-add-add &&
git init path &&
(
cd path &&
touch file-B &&
git add file-B &&
git commit -m B &&
git tag B
) &&
touch irrelevant-file &&
git add irrelevant-file &&
git commit -m A &&
git tag A &&
git checkout -b B A &&
git -C path reset --hard B &&
git add path &&
git commit -m B &&
git checkout -b C A &&
rm -rf path/ &&
test_ln_s_add irrelevant-file path &&
git commit -m C &&
git checkout -q B^0 &&
git merge -s ours -m D C^0 &&
git tag D &&
git checkout -q C^0 &&
git merge -s ours -m E B^0 &&
git tag E
)
'
test_expect_merge_algorithm failure success 'check conflicting entry types (submodule vs symlink)' '
(
cd submodule-symlink-add-add &&
git checkout D^0 &&
test_must_fail git merge -s recursive E^0 &&
git ls-files -s >out &&
test_line_count = 3 out &&
git ls-files -u >out &&
test_line_count = 2 out &&
git ls-files -o >out &&
test_line_count = 1 out
)
'
#
# criss-cross with regular files that have conflicting modes:
#
# B D
# o---o
# / \ / \
# A o X ? F
# \ / \ /
# o---o
# C E
#
# Commit A: nothing of note
# Commit B: introduce file source_me.bash, not executable
# Commit C: introduce file source_me.bash, executable
# Commit D: merge B&C, resolving in favor of B
# Commit E: merge B&C, resolving in favor of C
#
# This is an obvious add/add mode conflict. Can git detect it?
test_expect_success 'setup conflicting modes for regular file' '
git init regular-file-mode-conflict &&
(
cd regular-file-mode-conflict &&
touch irrelevant-file &&
git add irrelevant-file &&
git commit -m A &&
git tag A &&
git checkout -b B A &&
echo "command_to_run" >source_me.bash &&
git add source_me.bash &&
git commit -m B &&
git checkout -b C A &&
echo "command_to_run" >source_me.bash &&
git add source_me.bash &&
test_chmod +x source_me.bash &&
git commit -m C &&
git checkout -q B^0 &&
git merge -s ours -m D C^0 &&
git tag D &&
git checkout -q C^0 &&
git merge -s ours -m E B^0 &&
git tag E
)
'
test_expect_failure 'check conflicting modes for regular file' '
(
cd regular-file-mode-conflict &&
git checkout D^0 &&
test_must_fail git merge -s recursive E^0 &&
git ls-files -s >out &&
test_line_count = 3 out &&
git ls-files -u >out &&
test_line_count = 2 out &&
git ls-files -o >out &&
test_line_count = 1 out
)
'
# Setup:
# L1---L2
# / \ / \
# main X ?
# \ / \ /
# R1---R2
#
# Where:
# main has two files, named 'b' and 'a'
# branches L1 and R1 both modify each of the two files in conflicting ways
#
# L2 is a merge of R1 into L1; more on it later.
# R2 is a merge of L1 into R1; more on it later.
#
# X is an auto-generated merge-base used when merging L2 and R2.
# since X is a merge of L1 and R1, it has conflicting versions of each file
#
# More about L2 and R2:
# - both resolve the conflicts in 'b' and 'a' differently
# - L2 renames 'b' to 'm'
# - R2 renames 'a' to 'm'
#
# In the end, in file 'm' we have four different conflicting files (from
# two versions of 'b' and two of 'a'). In addition, if
# merge.conflictstyle is diff3, then the base version also has
# conflict markers of its own, leading to a total of three levels of
# conflict markers. This is a pretty weird corner case, but we just want
# to ensure that we handle it as well as practical.
test_expect_success 'setup nested conflicts' '
git init nested_conflicts &&
(
cd nested_conflicts &&
# Create some related files now
printf "Random base content line %d\n" $(test_seq 1 10) >initial &&
cp initial b_L1 &&
cp initial b_R1 &&
cp initial b_L2 &&
cp initial b_R2 &&
cp initial a_L1 &&
cp initial a_R1 &&
cp initial a_L2 &&
cp initial a_R2 &&
test_write_lines b b_L1 >>b_L1 &&
test_write_lines b b_R1 >>b_R1 &&
test_write_lines b b_L2 >>b_L2 &&
test_write_lines b b_R2 >>b_R2 &&
test_write_lines a a_L1 >>a_L1 &&
test_write_lines a a_R1 >>a_R1 &&
test_write_lines a a_L2 >>a_L2 &&
test_write_lines a a_R2 >>a_R2 &&
# Setup original commit (or merge-base), consisting of
# files named "b" and "a"
cp initial b &&
cp initial a &&
echo b >>b &&
echo a >>a &&
git add b a &&
test_tick && git commit -m initial &&
git branch L &&
git branch R &&
# Handle the left side
git checkout L &&
mv -f b_L1 b &&
mv -f a_L1 a &&
git add b a &&
test_tick && git commit -m "version L1 of files" &&
git tag L1 &&
# Handle the right side
git checkout R &&
mv -f b_R1 b &&
mv -f a_R1 a &&
git add b a &&
test_tick && git commit -m "version R1 of files" &&
git tag R1 &&
# Create first merge on left side
git checkout L &&
test_must_fail git merge R1 &&
mv -f b_L2 b &&
mv -f a_L2 a &&
git add b a &&
git mv b m &&
test_tick && git commit -m "left merge, rename b->m" &&
git tag L2 &&
# Create first merge on right side
git checkout R &&
test_must_fail git merge L1 &&
mv -f b_R2 b &&
mv -f a_R2 a &&
git add b a &&
git mv a m &&
test_tick && git commit -m "right merge, rename a->m" &&
git tag R2
)
'
test_expect_success 'check nested conflicts' '
(
cd nested_conflicts &&
git clean -f &&
MAIN=$(git rev-parse --short main) &&
git checkout L2^0 &&
# Merge must fail; there is a conflict
test_must_fail git -c merge.conflictstyle=diff3 merge -s recursive R2^0 &&
# 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 &&
# Create a and b from virtual merge base X
git cat-file -p main:a >base &&
git cat-file -p L1:a >ours &&
git cat-file -p R1:a >theirs &&
test_must_fail git merge-file --diff3 \
-L "Temporary merge branch 1" \
-L "$MAIN" \
-L "Temporary merge branch 2" \
ours \
base \
theirs &&
sed -e "s/^\([<|=>]\)/\1\1/" ours >vmb_a &&
git cat-file -p main:b >base &&
git cat-file -p L1:b >ours &&
git cat-file -p R1:b >theirs &&
test_must_fail git merge-file --diff3 \
-L "Temporary merge branch 1" \
-L "$MAIN" \
-L "Temporary merge branch 2" \
ours \
base \
theirs &&
sed -e "s/^\([<|=>]\)/\1\1/" ours >vmb_b &&
# Compare :2:m to expected values
git cat-file -p L2:m >ours &&
git cat-file -p R2:b >theirs &&
test_must_fail git merge-file --diff3 \
-L "HEAD:m" \
-L "merged common ancestors:b" \
-L "R2^0:b" \
ours \
vmb_b \
theirs &&
sed -e "s/^\([<|=>]\)/\1\1/" ours >m_stage_2 &&
git cat-file -p :2:m >actual &&
test_cmp m_stage_2 actual &&
# Compare :3:m to expected values
git cat-file -p L2:a >ours &&
git cat-file -p R2:m >theirs &&
test_must_fail git merge-file --diff3 \
-L "HEAD:a" \
-L "merged common ancestors:a" \
-L "R2^0:m" \
ours \
vmb_a \
theirs &&
sed -e "s/^\([<|=>]\)/\1\1/" ours >m_stage_3 &&
git cat-file -p :3:m >actual &&
test_cmp m_stage_3 actual &&
# Compare m to expected contents
>empty &&
cp m_stage_2 expected_final_m &&
test_must_fail git merge-file --diff3 \
-L "HEAD" \
-L "merged common ancestors" \
-L "R2^0" \
expected_final_m \
empty \
m_stage_3 &&
test_cmp expected_final_m m
)
'
# Setup:
# L1---L2---L3
# / \ / \ / \
# main X1 X2 ?
# \ / \ / \ /
# R1---R2---R3
#
# Where:
# main has one file named 'content'
# branches L1 and R1 both modify each of the two files in conflicting ways
#
# L<n> (n>1) is a merge of R<n-1> into L<n-1>
# R<n> (n>1) is a merge of L<n-1> into R<n-1>
# L<n> and R<n> resolve the conflicts differently.
#
# X<n> is an auto-generated merge-base used when merging L<n+1> and R<n+1>.
# By construction, X1 has conflict markers due to conflicting versions.
# X2, due to using merge.conflictstyle=3, has nested conflict markers.
#
# So, merging R3 into L3 using merge.conflictstyle=3 should show the
# nested conflict markers from X2 in the base version -- that means we
# have three levels of conflict markers. Can we distinguish all three?
test_expect_success 'setup virtual merge base with nested conflicts' '
git init virtual_merge_base_has_nested_conflicts &&
(
cd virtual_merge_base_has_nested_conflicts &&
# Create some related files now
printf "Random base content line %d\n" $(test_seq 1 10) >content &&
# Setup original commit
git add content &&
test_tick && git commit -m initial &&
git branch L &&
git branch R &&
# Create L1
git checkout L &&
echo left >>content &&
git add content &&
test_tick && git commit -m "version L1 of content" &&
git tag L1 &&
# Create R1
git checkout R &&
echo right >>content &&
git add content &&
test_tick && git commit -m "version R1 of content" &&
git tag R1 &&
# Create L2
git checkout L &&
test_must_fail git -c merge.conflictstyle=diff3 merge R1 &&
git checkout L1 content &&
test_tick && git commit -m "version L2 of content" &&
git tag L2 &&
# Create R2
git checkout R &&
test_must_fail git -c merge.conflictstyle=diff3 merge L1 &&
git checkout R1 content &&
test_tick && git commit -m "version R2 of content" &&
git tag R2 &&
# Create L3
git checkout L &&
test_must_fail git -c merge.conflictstyle=diff3 merge R2 &&
git checkout L1 content &&
test_tick && git commit -m "version L3 of content" &&
git tag L3 &&
# Create R3
git checkout R &&
test_must_fail git -c merge.conflictstyle=diff3 merge L2 &&
git checkout R1 content &&
test_tick && git commit -m "version R3 of content" &&
git tag R3
)
'
test_expect_success 'check virtual merge base with nested conflicts' '
(
cd virtual_merge_base_has_nested_conflicts &&
MAIN=$(git rev-parse --short main) &&
git checkout L3^0 &&
# Merge must fail; there is a conflict
test_must_fail git -c merge.conflictstyle=diff3 merge -s recursive R3^0 &&
# 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 = 3 out &&
# Ensure we have the correct number of untracked files
git ls-files -o >out &&
test_line_count = 1 out &&
# Compare :[23]:content to expected values
git rev-parse L1:content R1:content >expect &&
git rev-parse :2:content :3:content >actual &&
test_cmp expect actual &&
# Imitate X1 merge base, except without long enough conflict
# markers because a subsequent sed will modify them. Put
# result into vmb.
git cat-file -p main:content >base &&
git cat-file -p L:content >left &&
git cat-file -p R:content >right &&
cp left merged-once &&
test_must_fail git merge-file --diff3 \
-L "Temporary merge branch 1" \
-L "$MAIN" \
-L "Temporary merge branch 2" \
merged-once \
base \
right &&
sed -e "s/^\([<|=>]\)/\1\1\1/" merged-once >vmb &&
# Imitate X2 merge base, overwriting vmb. Note that we
# extend both sets of conflict markers to make them longer
# with the sed command.
cp left merged-twice &&
test_must_fail git merge-file --diff3 \
-L "Temporary merge branch 1" \
-L "merged common ancestors" \
-L "Temporary merge branch 2" \
merged-twice \
vmb \
right &&
sed -e "s/^\([<|=>]\)/\1\1\1/" merged-twice >vmb &&
# Compare :1:content to expected value
git cat-file -p :1:content >actual &&
test_cmp vmb actual &&
# Determine expected content in final outer merge, compare to
# what the merge generated.
cp -f left expect &&
test_must_fail git merge-file --diff3 \
-L "HEAD" -L "merged common ancestors" -L "R3^0" \
expect vmb right &&
test_cmp expect content
)
'
test_done