t/t6500-gc.sh - jrn/git - Git at Google

 #!/bin/sh

 test_description='basic git gc tests
 '

 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-terminal.sh

 test_expect_success 'setup' '
 	# do not let the amount of physical memory affects gc
 	# behavior, make sure we always pack everything to one pack by
 	# default
 	git config gc.bigPackThreshold 2g &&

 	# These are simply values which, when hashed as a blob with a newline,
 	# produce a hash where the first byte is 0x17 in their respective
 	# algorithms.
 	test_oid_cache <<-EOF
 	obj1 sha1:263
 	obj1 sha256:34

 	obj2 sha1:410
 	obj2 sha256:174

 	obj3 sha1:523
 	obj3 sha256:313

 	obj4 sha1:790
 	obj4 sha256:481
 	EOF
 '

 test_expect_success 'gc empty repository' '
 	git gc
 '

 test_expect_success 'gc does not leave behind pid file' '
 	git gc &&
 	test_path_is_missing .git/gc.pid
 '

 test_expect_success 'gc --gobbledegook' '
 	test_expect_code 129 git gc --nonsense 2>err &&
 	test_grep "[Uu]sage: git gc" err
 '

 test_expect_success 'gc -h with invalid configuration' '
 	mkdir broken &&
 	(
 		cd broken &&
 		git init &&
 		echo "[gc] pruneexpire = CORRUPT" >>.git/config &&
 		test_expect_code 129 git gc -h >usage 2>&1
 	) &&
 	test_grep "[Uu]sage" broken/usage
 '

 test_expect_success 'gc is not aborted due to a stale symref' '
 	git init remote &&
 	(
 		cd remote &&
 		test_commit initial &&
 		git clone . ../client &&
 		git branch -m develop &&
 		cd ../client &&
 		git fetch --prune &&
 		git gc
 	)
 '

 test_expect_success 'gc --keep-largest-pack' '
 	test_create_repo keep-pack &&
 	(
 		cd keep-pack &&
 		test_commit one &&
 		test_commit two &&
 		test_commit three &&
 		git gc &&
 		( cd .git/objects/pack && ls *.pack ) >pack-list &&
 		test_line_count = 1 pack-list &&
 		cp pack-list base-pack-list &&
 		test_commit four &&
 		git repack -d &&
 		test_commit five &&
 		git repack -d &&
 		( cd .git/objects/pack && ls *.pack ) >pack-list &&
 		test_line_count = 3 pack-list &&
 		git gc --keep-largest-pack &&
 		( cd .git/objects/pack && ls *.pack ) >pack-list &&
 		test_line_count = 2 pack-list &&
 		awk "/^P /{print \$2}" <.git/objects/info/packs >pack-info &&
 		test_line_count = 2 pack-info &&
 		test_path_is_file .git/objects/pack/$(cat base-pack-list) &&
 		git fsck
 	)
 '

 test_expect_success 'pre-auto-gc hook can stop auto gc' '
 	cat >err.expect <<-\EOF &&
 	no gc for you
 	EOF

 	git init pre-auto-gc-hook &&
 	test_hook -C pre-auto-gc-hook pre-auto-gc <<-\EOF &&
 	echo >&2 no gc for you &&
 	exit 1
 	EOF
 	(
 		cd pre-auto-gc-hook &&

 		git config gc.auto 3 &&
 		git config gc.autoDetach false &&

 		# We need to create two object whose sha1s start with 17
 		# since this is what git gc counts.  As it happens, these
 		# two blobs will do so.
 		test_commit "$(test_oid obj1)" &&
 		test_commit "$(test_oid obj2)" &&

 		git gc --auto >../out.actual 2>../err.actual
 	) &&
 	test_must_be_empty out.actual &&
 	test_cmp err.expect err.actual &&

 	cat >err.expect <<-\EOF &&
 	will gc for you
 	Auto packing the repository for optimum performance.
 	See "git help gc" for manual housekeeping.
 	EOF

 	test_hook -C pre-auto-gc-hook --clobber pre-auto-gc <<-\EOF &&
 	echo >&2 will gc for you &&
 	exit 0
 	EOF

 	git -C pre-auto-gc-hook gc --auto >out.actual 2>err.actual &&

 	test_must_be_empty out.actual &&
 	test_cmp err.expect err.actual
 '

 test_expect_success 'auto gc with too many loose objects does not attempt to create bitmaps' '
 	test_config gc.auto 3 &&
 	test_config gc.autodetach false &&
 	test_config pack.writebitmaps true &&
 	# We need to create two object whose sha1s start with 17
 	# since this is what git gc counts.  As it happens, these
 	# two blobs will do so.
 	test_commit "$(test_oid obj1)" &&
 	test_commit "$(test_oid obj2)" &&
 	# Our first gc will create a pack; our second will create a second pack
 	git gc --auto &&
 	ls .git/objects/pack/pack-*.pack | sort >existing_packs &&
 	test_commit "$(test_oid obj3)" &&
 	test_commit "$(test_oid obj4)" &&

 	git gc --auto 2>err &&
 	test_grep ! "^warning:" err &&
 	ls .git/objects/pack/pack-*.pack | sort >post_packs &&
 	comm -1 -3 existing_packs post_packs >new &&
 	comm -2 -3 existing_packs post_packs >del &&
 	test_line_count = 0 del && # No packs are deleted
 	test_line_count = 1 new # There is one new pack
 '

 test_expect_success 'gc --no-quiet' '
 	GIT_PROGRESS_DELAY=0 git -c gc.writeCommitGraph=true gc --no-quiet >stdout 2>stderr &&
 	test_must_be_empty stdout &&
 	test_grep "Computing commit graph generation numbers" stderr
 '

 test_expect_success TTY 'with TTY: gc --no-quiet' '
 	test_terminal env GIT_PROGRESS_DELAY=0 \
 		git -c gc.writeCommitGraph=true gc --no-quiet >stdout 2>stderr &&
 	test_must_be_empty stdout &&
 	test_grep "Enumerating objects" stderr &&
 	test_grep "Computing commit graph generation numbers" stderr
 '

 test_expect_success 'gc --quiet' '
 	git -c gc.writeCommitGraph=true gc --quiet >stdout 2>stderr &&
 	test_must_be_empty stdout &&
 	test_must_be_empty stderr
 '

 test_expect_success 'gc.reflogExpire{Unreachable,}=never skips "expire" via "gc"' '
 	test_config gc.reflogExpire never &&
 	test_config gc.reflogExpireUnreachable never &&

 	GIT_TRACE=$(pwd)/trace.out git gc &&

 	# Check that git-pack-refs is run as a sanity check (done via
 	# gc_before_repack()) but that git-expire is not.
 	grep -E "^trace: (built-in|exec|run_command): git pack-refs --" trace.out &&
 	! grep -E "^trace: (built-in|exec|run_command): git reflog expire --" trace.out
 '

 test_expect_success 'one of gc.reflogExpire{Unreachable,}=never does not skip "expire" via "gc"' '
 	>trace.out &&
 	test_config gc.reflogExpire never &&
 	GIT_TRACE=$(pwd)/trace.out git gc &&
 	grep -E "^trace: (built-in|exec|run_command): git reflog expire --" trace.out
 '

 test_expect_success 'gc.repackFilter launches repack with a filter' '
 	git clone --no-local --bare . bare.git &&

 	git -C bare.git -c gc.cruftPacks=false gc &&
 	test_stdout_line_count = 1 ls bare.git/objects/pack/*.pack &&

 	GIT_TRACE=$(pwd)/trace.out git -C bare.git -c gc.repackFilter=blob:none \
 		-c repack.writeBitmaps=false -c gc.cruftPacks=false gc &&
 	test_stdout_line_count = 2 ls bare.git/objects/pack/*.pack &&
 	grep -E "^trace: (built-in|exec|run_command): git repack .* --filter=blob:none ?.*" trace.out
 '

 test_expect_success 'gc.repackFilterTo store filtered out objects' '
 	test_when_finished "rm -rf bare.git filtered.git" &&

 	git init --bare filtered.git &&
 	git -C bare.git -c gc.repackFilter=blob:none \
 		-c gc.repackFilterTo=../filtered.git/objects/pack/pack \
 		-c repack.writeBitmaps=false -c gc.cruftPacks=false gc &&

 	test_stdout_line_count = 1 ls bare.git/objects/pack/*.pack &&
 	test_stdout_line_count = 1 ls filtered.git/objects/pack/*.pack
 '

 prepare_cruft_history () {
 	test_commit base &&

 	test_commit --no-tag foo &&
 	test_commit --no-tag bar &&
 	git reset HEAD^^
 }

 assert_no_cruft_packs () {
 	find .git/objects/pack -name "*.mtimes" >mtimes &&
 	test_must_be_empty mtimes
 }

 for argv in \
 	"gc" \
 	"-c gc.cruftPacks=true gc" \
 	"-c gc.cruftPacks=false gc --cruft"
 do
 	test_expect_success "git $argv generates a cruft pack" '
 		test_when_finished "rm -fr repo" &&
 		git init repo &&
 		(
 			cd repo &&

 			prepare_cruft_history &&
 			git $argv &&

 			find .git/objects/pack -name "*.mtimes" >mtimes &&
 			sed -e 's/\.mtimes$/\.pack/g' mtimes >packs &&

 			test_file_not_empty packs &&
 			while read pack
 			do
 				test_path_is_file "$pack" || return 1
 			done <packs
 		)
 	'
 done

 for argv in \
 	"gc --no-cruft" \
 	"-c gc.cruftPacks=false gc" \
 	"-c gc.cruftPacks=true gc --no-cruft"
 do
 	test_expect_success "git $argv does not generate a cruft pack" '
 		test_when_finished "rm -fr repo" &&
 		git init repo &&
 		(
 			cd repo &&

 			prepare_cruft_history &&
 			git $argv &&

 			assert_no_cruft_packs
 		)
 	'
 done

 test_expect_success '--keep-largest-pack ignores cruft packs' '
 	test_when_finished "rm -fr repo" &&
 	git init repo &&
 	(
 		cd repo &&

 		# Generate a pack for reachable objects (of which there
 		# are 3), and one for unreachable objects (of which
 		# there are 6).
 		prepare_cruft_history &&
 		git gc --cruft &&

 		mtimes="$(find .git/objects/pack -type f -name "pack-*.mtimes")" &&
 		sz="$(test_file_size "${mtimes%.mtimes}.pack")" &&

 		# Ensure that the cruft pack gets removed (due to
 		# `--prune=now`) despite it being the largest pack.
 		git -c gc.bigPackThreshold=$sz gc --cruft --prune=now &&

 		assert_no_cruft_packs
 	)
 '

 test_expect_success 'gc.bigPackThreshold ignores cruft packs' '
 	test_when_finished "rm -fr repo" &&
 	git init repo &&
 	(
 		cd repo &&

 		# Generate a pack for reachable objects (of which there
 		# are 3), and one for unreachable objects (of which
 		# there are 6).
 		prepare_cruft_history &&
 		git gc --cruft &&

 		# Ensure that the cruft pack gets removed (due to
 		# `--prune=now`) despite it being the largest pack.
 		git gc --cruft --prune=now --keep-largest-pack &&

 		assert_no_cruft_packs
 	)
 '

 cruft_max_size_opts="git repack -d -l --cruft --cruft-expiration=2.weeks.ago"

 test_expect_success 'setup for --max-cruft-size tests' '
 	git init cruft--max-size &&
 	(
 		cd cruft--max-size &&
 		prepare_cruft_history
 	)
 '

 test_expect_success '--max-cruft-size sets appropriate repack options' '
 	GIT_TRACE2_EVENT=$(pwd)/trace2.txt git -C cruft--max-size \
 		gc --cruft --max-cruft-size=1M &&
 	test_subcommand $cruft_max_size_opts --max-cruft-size=1048576 <trace2.txt
 '

 test_expect_success 'gc.maxCruftSize sets appropriate repack options' '
 	GIT_TRACE2_EVENT=$(pwd)/trace2.txt \
 		git -C cruft--max-size -c gc.maxCruftSize=2M gc --cruft &&
 	test_subcommand $cruft_max_size_opts --max-cruft-size=2097152 <trace2.txt &&

 	GIT_TRACE2_EVENT=$(pwd)/trace2.txt \
 		git -C cruft--max-size -c gc.maxCruftSize=2M gc --cruft \
 		--max-cruft-size=3M &&
 	test_subcommand $cruft_max_size_opts --max-cruft-size=3145728 <trace2.txt
 '

 run_and_wait_for_auto_gc () {
 	# We read stdout from gc for the side effect of waiting until the
 	# background gc process exits, closing its fd 9.  Furthermore, the
 	# variable assignment from a command substitution preserves the
 	# exit status of the main gc process.
 	# Note: this fd trickery doesn't work on Windows, but there is no
 	# need to, because on Win the auto gc always runs in the foreground.
 	doesnt_matter=$(git gc --auto 9>&1)
 }

 test_expect_success 'background auto gc does not run if gc.log is present and recent but does if it is old' '
 	test_commit foo &&
 	test_commit bar &&
 	git repack &&
 	test_config gc.autopacklimit 1 &&
 	test_config gc.autodetach true &&
 	echo fleem >.git/gc.log &&
 	git gc --auto 2>err &&
 	test_grep "^warning:" err &&
 	test_config gc.logexpiry 5.days &&
 	test-tool chmtime =-345600 .git/gc.log &&
 	git gc --auto &&
 	test_config gc.logexpiry 2.days &&
 	run_and_wait_for_auto_gc &&
 	ls .git/objects/pack/pack-*.pack >packs &&
 	test_line_count = 1 packs
 '

 test_expect_success 'background auto gc respects lock for all operations' '
 	# make sure we run a background auto-gc
 	test_commit make-pack &&
 	git repack &&
 	test_config gc.autopacklimit 1 &&
 	test_config gc.autodetach true &&

 	# create a ref whose loose presence we can use to detect a pack-refs run
 	git update-ref refs/heads/should-be-loose HEAD &&
 	(ls -1 .git/refs/heads .git/reftable >expect || true) &&

 	# now fake a concurrent gc that holds the lock; we can use our
 	# shell pid so that it looks valid.
 	hostname=$(hostname || echo unknown) &&
 	shell_pid=$$ &&
 	if test_have_prereq MINGW && test -f /proc/$shell_pid/winpid
 	then
 		# In Git for Windows, Bash (actually, the MSYS2 runtime) has a
 		# different idea of PIDs than git.exe (actually Windows). Use
 		# the Windows PID in this case.
 		shell_pid=$(cat /proc/$shell_pid/winpid)
 	fi &&
 	printf "%d %s" "$shell_pid" "$hostname" >.git/gc.pid &&

 	# our gc should exit zero without doing anything
 	run_and_wait_for_auto_gc &&
 	(ls -1 .git/refs/heads .git/reftable >actual || true) &&
 	test_cmp expect actual
 '

 # DO NOT leave a detached auto gc process running near the end of the
 # test script: it can run long enough in the background to racily
 # interfere with the cleanup in 'test_done'.

 test_done
	#!/bin/sh

	test_description='basic git gc tests
	'

	. ./test-lib.sh
	. "$TEST_DIRECTORY"/lib-terminal.sh

	test_expect_success 'setup' '
	# do not let the amount of physical memory affects gc
	# behavior, make sure we always pack everything to one pack by
	# default
	git config gc.bigPackThreshold 2g &&

	# These are simply values which, when hashed as a blob with a newline,
	# produce a hash where the first byte is 0x17 in their respective
	# algorithms.
	test_oid_cache <<-EOF
	obj1 sha1:263
	obj1 sha256:34

	obj2 sha1:410
	obj2 sha256:174

	obj3 sha1:523
	obj3 sha256:313

	obj4 sha1:790
	obj4 sha256:481
	EOF
	'

	test_expect_success 'gc empty repository' '
	git gc
	'

	test_expect_success 'gc does not leave behind pid file' '
	git gc &&
	test_path_is_missing .git/gc.pid
	'

	test_expect_success 'gc --gobbledegook' '
	test_expect_code 129 git gc --nonsense 2>err &&
	test_grep "[Uu]sage: git gc" err
	'

	test_expect_success 'gc -h with invalid configuration' '
	mkdir broken &&
	(
	cd broken &&
	git init &&
	echo "[gc] pruneexpire = CORRUPT" >>.git/config &&
	test_expect_code 129 git gc -h >usage 2>&1
	) &&
	test_grep "[Uu]sage" broken/usage
	'

	test_expect_success 'gc is not aborted due to a stale symref' '
	git init remote &&
	(
	cd remote &&
	test_commit initial &&
	git clone . ../client &&
	git branch -m develop &&
	cd ../client &&
	git fetch --prune &&
	git gc
	)
	'

	test_expect_success 'gc --keep-largest-pack' '
	test_create_repo keep-pack &&
	(
	cd keep-pack &&
	test_commit one &&
	test_commit two &&
	test_commit three &&
	git gc &&
	( cd .git/objects/pack && ls *.pack ) >pack-list &&
	test_line_count = 1 pack-list &&
	cp pack-list base-pack-list &&
	test_commit four &&
	git repack -d &&
	test_commit five &&
	git repack -d &&
	( cd .git/objects/pack && ls *.pack ) >pack-list &&
	test_line_count = 3 pack-list &&
	git gc --keep-largest-pack &&
	( cd .git/objects/pack && ls *.pack ) >pack-list &&
	test_line_count = 2 pack-list &&
	awk "/^P /{print \$2}" <.git/objects/info/packs >pack-info &&
	test_line_count = 2 pack-info &&
	test_path_is_file .git/objects/pack/$(cat base-pack-list) &&
	git fsck
	)
	'

	test_expect_success 'pre-auto-gc hook can stop auto gc' '
	cat >err.expect <<-\EOF &&
	no gc for you
	EOF

	git init pre-auto-gc-hook &&
	test_hook -C pre-auto-gc-hook pre-auto-gc <<-\EOF &&
	echo >&2 no gc for you &&
	exit 1
	EOF
	(
	cd pre-auto-gc-hook &&

	git config gc.auto 3 &&
	git config gc.autoDetach false &&

	# We need to create two object whose sha1s start with 17
	# since this is what git gc counts. As it happens, these
	# two blobs will do so.
	test_commit "$(test_oid obj1)" &&
	test_commit "$(test_oid obj2)" &&

	git gc --auto >../out.actual 2>../err.actual
	) &&
	test_must_be_empty out.actual &&
	test_cmp err.expect err.actual &&

	cat >err.expect <<-\EOF &&
	will gc for you
	Auto packing the repository for optimum performance.
	See "git help gc" for manual housekeeping.
	EOF

	test_hook -C pre-auto-gc-hook --clobber pre-auto-gc <<-\EOF &&
	echo >&2 will gc for you &&
	exit 0
	EOF

	git -C pre-auto-gc-hook gc --auto >out.actual 2>err.actual &&

	test_must_be_empty out.actual &&
	test_cmp err.expect err.actual
	'

	test_expect_success 'auto gc with too many loose objects does not attempt to create bitmaps' '
	test_config gc.auto 3 &&
	test_config gc.autodetach false &&
	test_config pack.writebitmaps true &&
	# We need to create two object whose sha1s start with 17
	# since this is what git gc counts. As it happens, these
	# two blobs will do so.
	test_commit "$(test_oid obj1)" &&
	test_commit "$(test_oid obj2)" &&
	# Our first gc will create a pack; our second will create a second pack
	git gc --auto &&
	ls .git/objects/pack/pack-*.pack \| sort >existing_packs &&
	test_commit "$(test_oid obj3)" &&
	test_commit "$(test_oid obj4)" &&

	git gc --auto 2>err &&
	test_grep ! "^warning:" err &&
	ls .git/objects/pack/pack-*.pack \| sort >post_packs &&
	comm -1 -3 existing_packs post_packs >new &&
	comm -2 -3 existing_packs post_packs >del &&
	test_line_count = 0 del && # No packs are deleted
	test_line_count = 1 new # There is one new pack
	'

	test_expect_success 'gc --no-quiet' '
	GIT_PROGRESS_DELAY=0 git -c gc.writeCommitGraph=true gc --no-quiet >stdout 2>stderr &&
	test_must_be_empty stdout &&
	test_grep "Computing commit graph generation numbers" stderr
	'

	test_expect_success TTY 'with TTY: gc --no-quiet' '
	test_terminal env GIT_PROGRESS_DELAY=0 \
	git -c gc.writeCommitGraph=true gc --no-quiet >stdout 2>stderr &&
	test_must_be_empty stdout &&
	test_grep "Enumerating objects" stderr &&
	test_grep "Computing commit graph generation numbers" stderr
	'

	test_expect_success 'gc --quiet' '
	git -c gc.writeCommitGraph=true gc --quiet >stdout 2>stderr &&
	test_must_be_empty stdout &&
	test_must_be_empty stderr
	'

	test_expect_success 'gc.reflogExpire{Unreachable,}=never skips "expire" via "gc"' '
	test_config gc.reflogExpire never &&
	test_config gc.reflogExpireUnreachable never &&

	GIT_TRACE=$(pwd)/trace.out git gc &&

	# Check that git-pack-refs is run as a sanity check (done via
	# gc_before_repack()) but that git-expire is not.
	grep -E "^trace: (built-in\|exec\|run_command): git pack-refs --" trace.out &&
	! grep -E "^trace: (built-in\|exec\|run_command): git reflog expire --" trace.out
	'

	test_expect_success 'one of gc.reflogExpire{Unreachable,}=never does not skip "expire" via "gc"' '
	>trace.out &&
	test_config gc.reflogExpire never &&
	GIT_TRACE=$(pwd)/trace.out git gc &&
	grep -E "^trace: (built-in\|exec\|run_command): git reflog expire --" trace.out
	'

	test_expect_success 'gc.repackFilter launches repack with a filter' '
	git clone --no-local --bare . bare.git &&

	git -C bare.git -c gc.cruftPacks=false gc &&
	test_stdout_line_count = 1 ls bare.git/objects/pack/*.pack &&

	GIT_TRACE=$(pwd)/trace.out git -C bare.git -c gc.repackFilter=blob:none \
	-c repack.writeBitmaps=false -c gc.cruftPacks=false gc &&
	test_stdout_line_count = 2 ls bare.git/objects/pack/*.pack &&
	grep -E "^trace: (built-in\|exec\|run_command): git repack .* --filter=blob:none ?.*" trace.out
	'

	test_expect_success 'gc.repackFilterTo store filtered out objects' '
	test_when_finished "rm -rf bare.git filtered.git" &&

	git init --bare filtered.git &&
	git -C bare.git -c gc.repackFilter=blob:none \
	-c gc.repackFilterTo=../filtered.git/objects/pack/pack \
	-c repack.writeBitmaps=false -c gc.cruftPacks=false gc &&

	test_stdout_line_count = 1 ls bare.git/objects/pack/*.pack &&
	test_stdout_line_count = 1 ls filtered.git/objects/pack/*.pack
	'

	prepare_cruft_history () {
	test_commit base &&

	test_commit --no-tag foo &&
	test_commit --no-tag bar &&
	git reset HEAD^^
	}

	assert_no_cruft_packs () {
	find .git/objects/pack -name "*.mtimes" >mtimes &&
	test_must_be_empty mtimes
	}

	for argv in \
	"gc" \
	"-c gc.cruftPacks=true gc" \
	"-c gc.cruftPacks=false gc --cruft"
	do
	test_expect_success "git $argv generates a cruft pack" '
	test_when_finished "rm -fr repo" &&
	git init repo &&
	(
	cd repo &&

	prepare_cruft_history &&
	git $argv &&

	find .git/objects/pack -name "*.mtimes" >mtimes &&
	sed -e 's/\.mtimes$/\.pack/g' mtimes >packs &&

	test_file_not_empty packs &&
	while read pack
	do
	test_path_is_file "$pack" \|\| return 1
	done <packs
	)
	'
	done

	for argv in \
	"gc --no-cruft" \
	"-c gc.cruftPacks=false gc" \
	"-c gc.cruftPacks=true gc --no-cruft"
	do
	test_expect_success "git $argv does not generate a cruft pack" '
	test_when_finished "rm -fr repo" &&
	git init repo &&
	(
	cd repo &&

	prepare_cruft_history &&
	git $argv &&

	assert_no_cruft_packs
	)
	'
	done

	test_expect_success '--keep-largest-pack ignores cruft packs' '
	test_when_finished "rm -fr repo" &&
	git init repo &&
	(
	cd repo &&

	# Generate a pack for reachable objects (of which there
	# are 3), and one for unreachable objects (of which
	# there are 6).
	prepare_cruft_history &&
	git gc --cruft &&

	mtimes="$(find .git/objects/pack -type f -name "pack-*.mtimes")" &&
	sz="$(test_file_size "${mtimes%.mtimes}.pack")" &&

	# Ensure that the cruft pack gets removed (due to
	# `--prune=now`) despite it being the largest pack.
	git -c gc.bigPackThreshold=$sz gc --cruft --prune=now &&

	assert_no_cruft_packs
	)
	'

	test_expect_success 'gc.bigPackThreshold ignores cruft packs' '
	test_when_finished "rm -fr repo" &&
	git init repo &&
	(
	cd repo &&

	# Generate a pack for reachable objects (of which there
	# are 3), and one for unreachable objects (of which
	# there are 6).
	prepare_cruft_history &&
	git gc --cruft &&

	# Ensure that the cruft pack gets removed (due to
	# `--prune=now`) despite it being the largest pack.
	git gc --cruft --prune=now --keep-largest-pack &&

	assert_no_cruft_packs
	)
	'

	cruft_max_size_opts="git repack -d -l --cruft --cruft-expiration=2.weeks.ago"

	test_expect_success 'setup for --max-cruft-size tests' '
	git init cruft--max-size &&
	(
	cd cruft--max-size &&
	prepare_cruft_history
	)
	'

	test_expect_success '--max-cruft-size sets appropriate repack options' '
	GIT_TRACE2_EVENT=$(pwd)/trace2.txt git -C cruft--max-size \
	gc --cruft --max-cruft-size=1M &&
	test_subcommand $cruft_max_size_opts --max-cruft-size=1048576 <trace2.txt
	'

	test_expect_success 'gc.maxCruftSize sets appropriate repack options' '
	GIT_TRACE2_EVENT=$(pwd)/trace2.txt \
	git -C cruft--max-size -c gc.maxCruftSize=2M gc --cruft &&
	test_subcommand $cruft_max_size_opts --max-cruft-size=2097152 <trace2.txt &&

	GIT_TRACE2_EVENT=$(pwd)/trace2.txt \
	git -C cruft--max-size -c gc.maxCruftSize=2M gc --cruft \
	--max-cruft-size=3M &&
	test_subcommand $cruft_max_size_opts --max-cruft-size=3145728 <trace2.txt
	'

	run_and_wait_for_auto_gc () {
	# We read stdout from gc for the side effect of waiting until the
	# background gc process exits, closing its fd 9. Furthermore, the
	# variable assignment from a command substitution preserves the
	# exit status of the main gc process.
	# Note: this fd trickery doesn't work on Windows, but there is no
	# need to, because on Win the auto gc always runs in the foreground.
	doesnt_matter=$(git gc --auto 9>&1)
	}

	test_expect_success 'background auto gc does not run if gc.log is present and recent but does if it is old' '
	test_commit foo &&
	test_commit bar &&
	git repack &&
	test_config gc.autopacklimit 1 &&
	test_config gc.autodetach true &&
	echo fleem >.git/gc.log &&
	git gc --auto 2>err &&
	test_grep "^warning:" err &&
	test_config gc.logexpiry 5.days &&
	test-tool chmtime =-345600 .git/gc.log &&
	git gc --auto &&
	test_config gc.logexpiry 2.days &&
	run_and_wait_for_auto_gc &&
	ls .git/objects/pack/pack-*.pack >packs &&
	test_line_count = 1 packs
	'

	test_expect_success 'background auto gc respects lock for all operations' '
	# make sure we run a background auto-gc
	test_commit make-pack &&
	git repack &&
	test_config gc.autopacklimit 1 &&
	test_config gc.autodetach true &&

	# create a ref whose loose presence we can use to detect a pack-refs run
	git update-ref refs/heads/should-be-loose HEAD &&
	(ls -1 .git/refs/heads .git/reftable >expect \|\| true) &&

	# now fake a concurrent gc that holds the lock; we can use our
	# shell pid so that it looks valid.
	hostname=$(hostname \|\| echo unknown) &&
	shell_pid=$$ &&
	if test_have_prereq MINGW && test -f /proc/$shell_pid/winpid
	then
	# In Git for Windows, Bash (actually, the MSYS2 runtime) has a
	# different idea of PIDs than git.exe (actually Windows). Use
	# the Windows PID in this case.
	shell_pid=$(cat /proc/$shell_pid/winpid)
	fi &&
	printf "%d %s" "$shell_pid" "$hostname" >.git/gc.pid &&

	# our gc should exit zero without doing anything
	run_and_wait_for_auto_gc &&
	(ls -1 .git/refs/heads .git/reftable >actual \|\| true) &&
	test_cmp expect actual
	'

	# DO NOT leave a detached auto gc process running near the end of the
	# test script: it can run long enough in the background to racily
	# interfere with the cleanup in 'test_done'.

	test_done