t/t0600-reffiles-backend.sh - jrn/git - Git at Google

 #!/bin/sh

 test_description='Test reffiles backend'

 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME

 TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh

 if ! test_have_prereq REFFILES
 then
 	skip_all='skipping reffiles specific tests'
 	test_done
 fi

 test_expect_success 'setup' '
 	git commit --allow-empty -m Initial &&
 	C=$(git rev-parse HEAD) &&
 	git commit --allow-empty -m Second &&
 	D=$(git rev-parse HEAD) &&
 	git commit --allow-empty -m Third &&
 	E=$(git rev-parse HEAD)
 '

 test_expect_success 'empty directory should not fool rev-parse' '
 	prefix=refs/e-rev-parse &&
 	git update-ref $prefix/foo $C &&
 	git pack-refs --all &&
 	mkdir -p .git/$prefix/foo/bar/baz &&
 	echo "$C" >expected &&
 	git rev-parse $prefix/foo >actual &&
 	test_cmp expected actual
 '

 test_expect_success 'empty directory should not fool for-each-ref' '
 	prefix=refs/e-for-each-ref &&
 	git update-ref $prefix/foo $C &&
 	git for-each-ref $prefix >expected &&
 	git pack-refs --all &&
 	mkdir -p .git/$prefix/foo/bar/baz &&
 	git for-each-ref $prefix >actual &&
 	test_cmp expected actual
 '

 test_expect_success 'empty directory should not fool create' '
 	prefix=refs/e-create &&
 	mkdir -p .git/$prefix/foo/bar/baz &&
 	printf "create %s $C\n" $prefix/foo |
 	git update-ref --stdin
 '

 test_expect_success 'empty directory should not fool verify' '
 	prefix=refs/e-verify &&
 	git update-ref $prefix/foo $C &&
 	git pack-refs --all &&
 	mkdir -p .git/$prefix/foo/bar/baz &&
 	printf "verify %s $C\n" $prefix/foo |
 	git update-ref --stdin
 '

 test_expect_success 'empty directory should not fool 1-arg update' '
 	prefix=refs/e-update-1 &&
 	git update-ref $prefix/foo $C &&
 	git pack-refs --all &&
 	mkdir -p .git/$prefix/foo/bar/baz &&
 	printf "update %s $D\n" $prefix/foo |
 	git update-ref --stdin
 '

 test_expect_success 'empty directory should not fool 2-arg update' '
 	prefix=refs/e-update-2 &&
 	git update-ref $prefix/foo $C &&
 	git pack-refs --all &&
 	mkdir -p .git/$prefix/foo/bar/baz &&
 	printf "update %s $D $C\n" $prefix/foo |
 	git update-ref --stdin
 '

 test_expect_success 'empty directory should not fool 0-arg delete' '
 	prefix=refs/e-delete-0 &&
 	git update-ref $prefix/foo $C &&
 	git pack-refs --all &&
 	mkdir -p .git/$prefix/foo/bar/baz &&
 	printf "delete %s\n" $prefix/foo |
 	git update-ref --stdin
 '

 test_expect_success 'empty directory should not fool 1-arg delete' '
 	prefix=refs/e-delete-1 &&
 	git update-ref $prefix/foo $C &&
 	git pack-refs --all &&
 	mkdir -p .git/$prefix/foo/bar/baz &&
 	printf "delete %s $C\n" $prefix/foo |
 	git update-ref --stdin
 '

 test_expect_success 'non-empty directory blocks create' '
 	prefix=refs/ne-create &&
 	mkdir -p .git/$prefix/foo/bar &&
 	: >.git/$prefix/foo/bar/baz.lock &&
 	test_when_finished "rm -f .git/$prefix/foo/bar/baz.lock" &&
 	cat >expected <<-EOF &&
 	fatal: cannot lock ref $SQ$prefix/foo$SQ: there is a non-empty directory $SQ.git/$prefix/foo$SQ blocking reference $SQ$prefix/foo$SQ
 	EOF
 	printf "%s\n" "update $prefix/foo $C" |
 	test_must_fail git update-ref --stdin 2>output.err &&
 	test_cmp expected output.err &&
 	cat >expected <<-EOF &&
 	fatal: cannot lock ref $SQ$prefix/foo$SQ: unable to resolve reference $SQ$prefix/foo$SQ
 	EOF
 	printf "%s\n" "update $prefix/foo $D $C" |
 	test_must_fail git update-ref --stdin 2>output.err &&
 	test_cmp expected output.err
 '

 test_expect_success 'broken reference blocks create' '
 	prefix=refs/broken-create &&
 	mkdir -p .git/$prefix &&
 	echo "gobbledigook" >.git/$prefix/foo &&
 	test_when_finished "rm -f .git/$prefix/foo" &&
 	cat >expected <<-EOF &&
 	fatal: cannot lock ref $SQ$prefix/foo$SQ: unable to resolve reference $SQ$prefix/foo$SQ: reference broken
 	EOF
 	printf "%s\n" "update $prefix/foo $C" |
 	test_must_fail git update-ref --stdin 2>output.err &&
 	test_cmp expected output.err &&
 	cat >expected <<-EOF &&
 	fatal: cannot lock ref $SQ$prefix/foo$SQ: unable to resolve reference $SQ$prefix/foo$SQ: reference broken
 	EOF
 	printf "%s\n" "update $prefix/foo $D $C" |
 	test_must_fail git update-ref --stdin 2>output.err &&
 	test_cmp expected output.err
 '

 test_expect_success 'non-empty directory blocks indirect create' '
 	prefix=refs/ne-indirect-create &&
 	git symbolic-ref $prefix/symref $prefix/foo &&
 	mkdir -p .git/$prefix/foo/bar &&
 	: >.git/$prefix/foo/bar/baz.lock &&
 	test_when_finished "rm -f .git/$prefix/foo/bar/baz.lock" &&
 	cat >expected <<-EOF &&
 	fatal: cannot lock ref $SQ$prefix/symref$SQ: there is a non-empty directory $SQ.git/$prefix/foo$SQ blocking reference $SQ$prefix/foo$SQ
 	EOF
 	printf "%s\n" "update $prefix/symref $C" |
 	test_must_fail git update-ref --stdin 2>output.err &&
 	test_cmp expected output.err &&
 	cat >expected <<-EOF &&
 	fatal: cannot lock ref $SQ$prefix/symref$SQ: unable to resolve reference $SQ$prefix/foo$SQ
 	EOF
 	printf "%s\n" "update $prefix/symref $D $C" |
 	test_must_fail git update-ref --stdin 2>output.err &&
 	test_cmp expected output.err
 '

 test_expect_success 'broken reference blocks indirect create' '
 	prefix=refs/broken-indirect-create &&
 	git symbolic-ref $prefix/symref $prefix/foo &&
 	echo "gobbledigook" >.git/$prefix/foo &&
 	test_when_finished "rm -f .git/$prefix/foo" &&
 	cat >expected <<-EOF &&
 	fatal: cannot lock ref $SQ$prefix/symref$SQ: unable to resolve reference $SQ$prefix/foo$SQ: reference broken
 	EOF
 	printf "%s\n" "update $prefix/symref $C" |
 	test_must_fail git update-ref --stdin 2>output.err &&
 	test_cmp expected output.err &&
 	cat >expected <<-EOF &&
 	fatal: cannot lock ref $SQ$prefix/symref$SQ: unable to resolve reference $SQ$prefix/foo$SQ: reference broken
 	EOF
 	printf "%s\n" "update $prefix/symref $D $C" |
 	test_must_fail git update-ref --stdin 2>output.err &&
 	test_cmp expected output.err
 '

 test_expect_success 'no bogus intermediate values during delete' '
 	prefix=refs/slow-transaction &&
 	# Set up a reference with differing loose and packed versions:
 	git update-ref $prefix/foo $C &&
 	git pack-refs --all &&
 	git update-ref $prefix/foo $D &&
 	# Now try to update the reference, but hold the `packed-refs` lock
 	# for a while to see what happens while the process is blocked:
 	: >.git/packed-refs.lock &&
 	test_when_finished "rm -f .git/packed-refs.lock" &&
 	{
 		# Note: the following command is intentionally run in the
 		# background. We increase the timeout so that `update-ref`
 		# attempts to acquire the `packed-refs` lock for much longer
 		# than it takes for us to do the check then delete it:
 		git -c core.packedrefstimeout=30000 update-ref -d $prefix/foo &
 	} &&
 	pid2=$! &&
 	# Give update-ref plenty of time to get to the point where it tries
 	# to lock packed-refs:
 	sleep 1 &&
 	# Make sure that update-ref did not complete despite the lock:
 	kill -0 $pid2 &&
 	# Verify that the reference still has its old value:
 	sha1=$(git rev-parse --verify --quiet $prefix/foo || echo undefined) &&
 	case "$sha1" in
 	$D)
 		# This is what we hope for; it means that nothing
 		# user-visible has changed yet.
 		: ;;
 	undefined)
 		# This is not correct; it means the deletion has happened
 		# already even though update-ref should not have been
 		# able to acquire the lock yet.
 		echo "$prefix/foo deleted prematurely" &&
 		break
 		;;
 	$C)
 		# This value should never be seen. Probably the loose
 		# reference has been deleted but the packed reference
 		# is still there:
 		echo "$prefix/foo incorrectly observed to be C" &&
 		break
 		;;
 	*)
 		# WTF?
 		echo "unexpected value observed for $prefix/foo: $sha1" &&
 		break
 		;;
 	esac >out &&
 	rm -f .git/packed-refs.lock &&
 	wait $pid2 &&
 	test_must_be_empty out &&
 	test_must_fail git rev-parse --verify --quiet $prefix/foo
 '

 test_expect_success 'delete fails cleanly if packed-refs file is locked' '
 	prefix=refs/locked-packed-refs &&
 	# Set up a reference with differing loose and packed versions:
 	git update-ref $prefix/foo $C &&
 	git pack-refs --all &&
 	git update-ref $prefix/foo $D &&
 	git for-each-ref $prefix >unchanged &&
 	# Now try to delete it while the `packed-refs` lock is held:
 	: >.git/packed-refs.lock &&
 	test_when_finished "rm -f .git/packed-refs.lock" &&
 	test_must_fail git update-ref -d $prefix/foo >out 2>err &&
 	git for-each-ref $prefix >actual &&
 	test_grep "Unable to create $SQ.*packed-refs.lock$SQ: " err &&
 	test_cmp unchanged actual
 '

 test_expect_success 'delete fails cleanly if packed-refs.new write fails' '
 	# Setup and expectations are similar to the test above.
 	prefix=refs/failed-packed-refs &&
 	git update-ref $prefix/foo $C &&
 	git pack-refs --all &&
 	git update-ref $prefix/foo $D &&
 	git for-each-ref $prefix >unchanged &&
 	# This should not happen in practice, but it is an easy way to get a
 	# reliable error (we open with create_tempfile(), which uses O_EXCL).
 	: >.git/packed-refs.new &&
 	test_when_finished "rm -f .git/packed-refs.new" &&
 	test_must_fail git update-ref -d $prefix/foo &&
 	git for-each-ref $prefix >actual &&
 	test_cmp unchanged actual
 '

 RWT="test-tool ref-store worktree:wt"
 RMAIN="test-tool ref-store worktree:main"

 test_expect_success 'setup worktree' '
 	test_commit first &&
 	git worktree add -b wt-main wt &&
 	(
 		cd wt &&
 		test_commit second
 	)
 '

 # Some refs (refs/bisect/*, pseudorefs) are kept per worktree, so they should
 # only appear in the for-each-reflog output if it is called from the correct
 # worktree, which is exercised in this test. This test is poorly written for
 # mulitple reasons: 1) it creates invalidly formatted log entres. 2) it uses
 # direct FS access for creating the reflogs. 3) PSEUDO-WT and refs/bisect/random
 # do not create reflogs by default, so it is not testing a realistic scenario.
 test_expect_success 'for_each_reflog()' '
 	echo $ZERO_OID > .git/logs/PSEUDO-MAIN &&
 	mkdir -p     .git/logs/refs/bisect &&
 	echo $ZERO_OID > .git/logs/refs/bisect/random &&

 	echo $ZERO_OID > .git/worktrees/wt/logs/PSEUDO-WT &&
 	mkdir -p     .git/worktrees/wt/logs/refs/bisect &&
 	echo $ZERO_OID > .git/worktrees/wt/logs/refs/bisect/wt-random &&

 	$RWT for-each-reflog | cut -d" " -f 2- | sort >actual &&
 	cat >expected <<-\EOF &&
 	HEAD 0x1
 	PSEUDO-WT 0x0
 	refs/bisect/wt-random 0x0
 	refs/heads/main 0x0
 	refs/heads/wt-main 0x0
 	EOF
 	test_cmp expected actual &&

 	$RMAIN for-each-reflog | cut -d" " -f 2- | sort >actual &&
 	cat >expected <<-\EOF &&
 	HEAD 0x1
 	PSEUDO-MAIN 0x0
 	refs/bisect/random 0x0
 	refs/heads/main 0x0
 	refs/heads/wt-main 0x0
 	EOF
 	test_cmp expected actual
 '

 # Triggering the bug detected by this test requires a newline to fall
 # exactly BUFSIZ-1 bytes from the end of the file. We don't know
 # what that value is, since it's platform dependent. However, if
 # we choose some value N, we also catch any D which divides N evenly
 # (since we will read backwards in chunks of D). So we choose 8K,
 # which catches glibc (with an 8K BUFSIZ) and *BSD (1K).
 #
 # Each line is 114 characters, so we need 75 to still have a few before the
 # last 8K. The 89-character padding on the final entry lines up our
 # newline exactly.
 test_expect_success SHA1 'parsing reverse reflogs at BUFSIZ boundaries' '
 	git checkout -b reflogskip &&
 	zf=$(test_oid zero_2) &&
 	ident="abc <xyz> 0000000001 +0000" &&
 	for i in $(test_seq 1 75); do
 		printf "$zf%02d $zf%02d %s\t" $i $(($i+1)) "$ident" &&
 		if test $i = 75; then
 			for j in $(test_seq 1 89); do
 				printf X || return 1
 			done
 		else
 			printf X
 		fi &&
 		printf "\n" || return 1
 	done >.git/logs/refs/heads/reflogskip &&
 	git rev-parse reflogskip@{73} >actual &&
 	echo ${zf}03 >expect &&
 	test_cmp expect actual
 '

 # This test takes a lock on an individual ref; this is not supported in
 # reftable.
 test_expect_success 'reflog expire operates on symref not referrent' '
 	git branch --create-reflog the_symref &&
 	git branch --create-reflog referrent &&
 	git update-ref referrent HEAD &&
 	git symbolic-ref refs/heads/the_symref refs/heads/referrent &&
 	test_when_finished "rm -f .git/refs/heads/referrent.lock" &&
 	touch .git/refs/heads/referrent.lock &&
 	git reflog expire --expire=all the_symref
 '

 test_expect_success 'empty reflog' '
 	test_when_finished "rm -rf empty" &&
 	git init empty &&
 	test_commit -C empty A &&
 	>empty/.git/logs/refs/heads/foo &&
 	git -C empty reflog expire --all 2>err &&
 	test_must_be_empty err
 '

 test_expect_success SYMLINKS 'ref resolution not confused by broken symlinks' '
        ln -s does-not-exist .git/refs/heads/broken &&
        test_must_fail git rev-parse --verify broken
 '

 test_expect_success 'log diagnoses bogus HEAD hash' '
 	git init empty &&
 	test_when_finished "rm -rf empty" &&
 	echo 1234abcd >empty/.git/refs/heads/main &&
 	test_must_fail git -C empty log 2>stderr &&
 	test_grep broken stderr
 '

 test_expect_success 'log diagnoses bogus HEAD symref' '
 	git init empty &&
 	test-tool -C empty ref-store main create-symref HEAD refs/heads/invalid.lock &&
 	test_must_fail git -C empty log 2>stderr &&
 	test_grep broken stderr &&
 	test_must_fail git -C empty log --default totally-bogus 2>stderr &&
 	test_grep broken stderr
 '

 test_done
	#!/bin/sh

	test_description='Test reffiles backend'

	GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
	export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME

	TEST_PASSES_SANITIZE_LEAK=true
	. ./test-lib.sh

	if ! test_have_prereq REFFILES
	then
	skip_all='skipping reffiles specific tests'
	test_done
	fi

	test_expect_success 'setup' '
	git commit --allow-empty -m Initial &&
	C=$(git rev-parse HEAD) &&
	git commit --allow-empty -m Second &&
	D=$(git rev-parse HEAD) &&
	git commit --allow-empty -m Third &&
	E=$(git rev-parse HEAD)
	'

	test_expect_success 'empty directory should not fool rev-parse' '
	prefix=refs/e-rev-parse &&
	git update-ref $prefix/foo $C &&
	git pack-refs --all &&
	mkdir -p .git/$prefix/foo/bar/baz &&
	echo "$C" >expected &&
	git rev-parse $prefix/foo >actual &&
	test_cmp expected actual
	'

	test_expect_success 'empty directory should not fool for-each-ref' '
	prefix=refs/e-for-each-ref &&
	git update-ref $prefix/foo $C &&
	git for-each-ref $prefix >expected &&
	git pack-refs --all &&
	mkdir -p .git/$prefix/foo/bar/baz &&
	git for-each-ref $prefix >actual &&
	test_cmp expected actual
	'

	test_expect_success 'empty directory should not fool create' '
	prefix=refs/e-create &&
	mkdir -p .git/$prefix/foo/bar/baz &&
	printf "create %s $C\n" $prefix/foo \|
	git update-ref --stdin
	'

	test_expect_success 'empty directory should not fool verify' '
	prefix=refs/e-verify &&
	git update-ref $prefix/foo $C &&
	git pack-refs --all &&
	mkdir -p .git/$prefix/foo/bar/baz &&
	printf "verify %s $C\n" $prefix/foo \|
	git update-ref --stdin
	'

	test_expect_success 'empty directory should not fool 1-arg update' '
	prefix=refs/e-update-1 &&
	git update-ref $prefix/foo $C &&
	git pack-refs --all &&
	mkdir -p .git/$prefix/foo/bar/baz &&
	printf "update %s $D\n" $prefix/foo \|
	git update-ref --stdin
	'

	test_expect_success 'empty directory should not fool 2-arg update' '
	prefix=refs/e-update-2 &&
	git update-ref $prefix/foo $C &&
	git pack-refs --all &&
	mkdir -p .git/$prefix/foo/bar/baz &&
	printf "update %s $D $C\n" $prefix/foo \|
	git update-ref --stdin
	'

	test_expect_success 'empty directory should not fool 0-arg delete' '
	prefix=refs/e-delete-0 &&
	git update-ref $prefix/foo $C &&
	git pack-refs --all &&
	mkdir -p .git/$prefix/foo/bar/baz &&
	printf "delete %s\n" $prefix/foo \|
	git update-ref --stdin
	'

	test_expect_success 'empty directory should not fool 1-arg delete' '
	prefix=refs/e-delete-1 &&
	git update-ref $prefix/foo $C &&
	git pack-refs --all &&
	mkdir -p .git/$prefix/foo/bar/baz &&
	printf "delete %s $C\n" $prefix/foo \|
	git update-ref --stdin
	'

	test_expect_success 'non-empty directory blocks create' '
	prefix=refs/ne-create &&
	mkdir -p .git/$prefix/foo/bar &&
	: >.git/$prefix/foo/bar/baz.lock &&
	test_when_finished "rm -f .git/$prefix/foo/bar/baz.lock" &&
	cat >expected <<-EOF &&
	fatal: cannot lock ref $SQ$prefix/foo$SQ: there is a non-empty directory $SQ.git/$prefix/foo$SQ blocking reference $SQ$prefix/foo$SQ
	EOF
	printf "%s\n" "update $prefix/foo $C" \|
	test_must_fail git update-ref --stdin 2>output.err &&
	test_cmp expected output.err &&
	cat >expected <<-EOF &&
	fatal: cannot lock ref $SQ$prefix/foo$SQ: unable to resolve reference $SQ$prefix/foo$SQ
	EOF
	printf "%s\n" "update $prefix/foo $D $C" \|
	test_must_fail git update-ref --stdin 2>output.err &&
	test_cmp expected output.err
	'

	test_expect_success 'broken reference blocks create' '
	prefix=refs/broken-create &&
	mkdir -p .git/$prefix &&
	echo "gobbledigook" >.git/$prefix/foo &&
	test_when_finished "rm -f .git/$prefix/foo" &&
	cat >expected <<-EOF &&
	fatal: cannot lock ref $SQ$prefix/foo$SQ: unable to resolve reference $SQ$prefix/foo$SQ: reference broken
	EOF
	printf "%s\n" "update $prefix/foo $C" \|
	test_must_fail git update-ref --stdin 2>output.err &&
	test_cmp expected output.err &&
	cat >expected <<-EOF &&
	fatal: cannot lock ref $SQ$prefix/foo$SQ: unable to resolve reference $SQ$prefix/foo$SQ: reference broken
	EOF
	printf "%s\n" "update $prefix/foo $D $C" \|
	test_must_fail git update-ref --stdin 2>output.err &&
	test_cmp expected output.err
	'

	test_expect_success 'non-empty directory blocks indirect create' '
	prefix=refs/ne-indirect-create &&
	git symbolic-ref $prefix/symref $prefix/foo &&
	mkdir -p .git/$prefix/foo/bar &&
	: >.git/$prefix/foo/bar/baz.lock &&
	test_when_finished "rm -f .git/$prefix/foo/bar/baz.lock" &&
	cat >expected <<-EOF &&
	fatal: cannot lock ref $SQ$prefix/symref$SQ: there is a non-empty directory $SQ.git/$prefix/foo$SQ blocking reference $SQ$prefix/foo$SQ
	EOF
	printf "%s\n" "update $prefix/symref $C" \|
	test_must_fail git update-ref --stdin 2>output.err &&
	test_cmp expected output.err &&
	cat >expected <<-EOF &&
	fatal: cannot lock ref $SQ$prefix/symref$SQ: unable to resolve reference $SQ$prefix/foo$SQ
	EOF
	printf "%s\n" "update $prefix/symref $D $C" \|
	test_must_fail git update-ref --stdin 2>output.err &&
	test_cmp expected output.err
	'

	test_expect_success 'broken reference blocks indirect create' '
	prefix=refs/broken-indirect-create &&
	git symbolic-ref $prefix/symref $prefix/foo &&
	echo "gobbledigook" >.git/$prefix/foo &&
	test_when_finished "rm -f .git/$prefix/foo" &&
	cat >expected <<-EOF &&
	fatal: cannot lock ref $SQ$prefix/symref$SQ: unable to resolve reference $SQ$prefix/foo$SQ: reference broken
	EOF
	printf "%s\n" "update $prefix/symref $C" \|
	test_must_fail git update-ref --stdin 2>output.err &&
	test_cmp expected output.err &&
	cat >expected <<-EOF &&
	fatal: cannot lock ref $SQ$prefix/symref$SQ: unable to resolve reference $SQ$prefix/foo$SQ: reference broken
	EOF
	printf "%s\n" "update $prefix/symref $D $C" \|
	test_must_fail git update-ref --stdin 2>output.err &&
	test_cmp expected output.err
	'

	test_expect_success 'no bogus intermediate values during delete' '
	prefix=refs/slow-transaction &&
	# Set up a reference with differing loose and packed versions:
	git update-ref $prefix/foo $C &&
	git pack-refs --all &&
	git update-ref $prefix/foo $D &&
	# Now try to update the reference, but hold the `packed-refs` lock
	# for a while to see what happens while the process is blocked:
	: >.git/packed-refs.lock &&
	test_when_finished "rm -f .git/packed-refs.lock" &&
	{
	# Note: the following command is intentionally run in the
	# background. We increase the timeout so that `update-ref`
	# attempts to acquire the `packed-refs` lock for much longer
	# than it takes for us to do the check then delete it:
	git -c core.packedrefstimeout=30000 update-ref -d $prefix/foo &
	} &&
	pid2=$! &&
	# Give update-ref plenty of time to get to the point where it tries
	# to lock packed-refs:
	sleep 1 &&
	# Make sure that update-ref did not complete despite the lock:
	kill -0 $pid2 &&
	# Verify that the reference still has its old value:
	sha1=$(git rev-parse --verify --quiet $prefix/foo \|\| echo undefined) &&
	case "$sha1" in
	$D)
	# This is what we hope for; it means that nothing
	# user-visible has changed yet.
	: ;;
	undefined)
	# This is not correct; it means the deletion has happened
	# already even though update-ref should not have been
	# able to acquire the lock yet.
	echo "$prefix/foo deleted prematurely" &&
	break
	;;
	$C)
	# This value should never be seen. Probably the loose
	# reference has been deleted but the packed reference
	# is still there:
	echo "$prefix/foo incorrectly observed to be C" &&
	break
	;;
	*)
	# WTF?
	echo "unexpected value observed for $prefix/foo: $sha1" &&
	break
	;;
	esac >out &&
	rm -f .git/packed-refs.lock &&
	wait $pid2 &&
	test_must_be_empty out &&
	test_must_fail git rev-parse --verify --quiet $prefix/foo
	'

	test_expect_success 'delete fails cleanly if packed-refs file is locked' '
	prefix=refs/locked-packed-refs &&
	# Set up a reference with differing loose and packed versions:
	git update-ref $prefix/foo $C &&
	git pack-refs --all &&
	git update-ref $prefix/foo $D &&
	git for-each-ref $prefix >unchanged &&
	# Now try to delete it while the `packed-refs` lock is held:
	: >.git/packed-refs.lock &&
	test_when_finished "rm -f .git/packed-refs.lock" &&
	test_must_fail git update-ref -d $prefix/foo >out 2>err &&
	git for-each-ref $prefix >actual &&
	test_grep "Unable to create $SQ.*packed-refs.lock$SQ: " err &&
	test_cmp unchanged actual
	'

	test_expect_success 'delete fails cleanly if packed-refs.new write fails' '
	# Setup and expectations are similar to the test above.
	prefix=refs/failed-packed-refs &&
	git update-ref $prefix/foo $C &&
	git pack-refs --all &&
	git update-ref $prefix/foo $D &&
	git for-each-ref $prefix >unchanged &&
	# This should not happen in practice, but it is an easy way to get a
	# reliable error (we open with create_tempfile(), which uses O_EXCL).
	: >.git/packed-refs.new &&
	test_when_finished "rm -f .git/packed-refs.new" &&
	test_must_fail git update-ref -d $prefix/foo &&
	git for-each-ref $prefix >actual &&
	test_cmp unchanged actual
	'

	RWT="test-tool ref-store worktree:wt"
	RMAIN="test-tool ref-store worktree:main"

	test_expect_success 'setup worktree' '
	test_commit first &&
	git worktree add -b wt-main wt &&
	(
	cd wt &&
	test_commit second
	)
	'

	# Some refs (refs/bisect/*, pseudorefs) are kept per worktree, so they should
	# only appear in the for-each-reflog output if it is called from the correct
	# worktree, which is exercised in this test. This test is poorly written for
	# mulitple reasons: 1) it creates invalidly formatted log entres. 2) it uses
	# direct FS access for creating the reflogs. 3) PSEUDO-WT and refs/bisect/random
	# do not create reflogs by default, so it is not testing a realistic scenario.
	test_expect_success 'for_each_reflog()' '
	echo $ZERO_OID > .git/logs/PSEUDO-MAIN &&
	mkdir -p .git/logs/refs/bisect &&
	echo $ZERO_OID > .git/logs/refs/bisect/random &&

	echo $ZERO_OID > .git/worktrees/wt/logs/PSEUDO-WT &&
	mkdir -p .git/worktrees/wt/logs/refs/bisect &&
	echo $ZERO_OID > .git/worktrees/wt/logs/refs/bisect/wt-random &&

	$RWT for-each-reflog \| cut -d" " -f 2- \| sort >actual &&
	cat >expected <<-\EOF &&
	HEAD 0x1
	PSEUDO-WT 0x0
	refs/bisect/wt-random 0x0
	refs/heads/main 0x0
	refs/heads/wt-main 0x0
	EOF
	test_cmp expected actual &&

	$RMAIN for-each-reflog \| cut -d" " -f 2- \| sort >actual &&
	cat >expected <<-\EOF &&
	HEAD 0x1
	PSEUDO-MAIN 0x0
	refs/bisect/random 0x0
	refs/heads/main 0x0
	refs/heads/wt-main 0x0
	EOF
	test_cmp expected actual
	'

	# Triggering the bug detected by this test requires a newline to fall
	# exactly BUFSIZ-1 bytes from the end of the file. We don't know
	# what that value is, since it's platform dependent. However, if
	# we choose some value N, we also catch any D which divides N evenly
	# (since we will read backwards in chunks of D). So we choose 8K,
	# which catches glibc (with an 8K BUFSIZ) and *BSD (1K).
	#
	# Each line is 114 characters, so we need 75 to still have a few before the
	# last 8K. The 89-character padding on the final entry lines up our
	# newline exactly.
	test_expect_success SHA1 'parsing reverse reflogs at BUFSIZ boundaries' '
	git checkout -b reflogskip &&
	zf=$(test_oid zero_2) &&
	ident="abc <xyz> 0000000001 +0000" &&
	for i in $(test_seq 1 75); do
	printf "$zf%02d $zf%02d %s\t" $i $(($i+1)) "$ident" &&
	if test $i = 75; then
	for j in $(test_seq 1 89); do
	printf X \|\| return 1
	done
	else
	printf X
	fi &&
	printf "\n" \|\| return 1
	done >.git/logs/refs/heads/reflogskip &&
	git rev-parse reflogskip@{73} >actual &&
	echo ${zf}03 >expect &&
	test_cmp expect actual
	'

	# This test takes a lock on an individual ref; this is not supported in
	# reftable.
	test_expect_success 'reflog expire operates on symref not referrent' '
	git branch --create-reflog the_symref &&
	git branch --create-reflog referrent &&
	git update-ref referrent HEAD &&
	git symbolic-ref refs/heads/the_symref refs/heads/referrent &&
	test_when_finished "rm -f .git/refs/heads/referrent.lock" &&
	touch .git/refs/heads/referrent.lock &&
	git reflog expire --expire=all the_symref
	'

	test_expect_success 'empty reflog' '
	test_when_finished "rm -rf empty" &&
	git init empty &&
	test_commit -C empty A &&
	>empty/.git/logs/refs/heads/foo &&
	git -C empty reflog expire --all 2>err &&
	test_must_be_empty err
	'

	test_expect_success SYMLINKS 'ref resolution not confused by broken symlinks' '
	ln -s does-not-exist .git/refs/heads/broken &&
	test_must_fail git rev-parse --verify broken
	'

	test_expect_success 'log diagnoses bogus HEAD hash' '
	git init empty &&
	test_when_finished "rm -rf empty" &&
	echo 1234abcd >empty/.git/refs/heads/main &&
	test_must_fail git -C empty log 2>stderr &&
	test_grep broken stderr
	'

	test_expect_success 'log diagnoses bogus HEAD symref' '
	git init empty &&
	test-tool -C empty ref-store main create-symref HEAD refs/heads/invalid.lock &&
	test_must_fail git -C empty log 2>stderr &&
	test_grep broken stderr &&
	test_must_fail git -C empty log --default totally-bogus 2>stderr &&
	test_grep broken stderr
	'

	test_done