git-bisect.sh - jrn/git - Git at Google

 #!/bin/sh

 USAGE='[help|start|bad|good|skip|next|reset|visualize|replay|log|run]'
 LONG_USAGE='git bisect help
 	print this long help message.
 git bisect start [--no-checkout] [<bad> [<good>...]] [--] [<pathspec>...]
 	reset bisect state and start bisection.
 git bisect bad [<rev>]
 	mark <rev> a known-bad revision.
 git bisect good [<rev>...]
 	mark <rev>... known-good revisions.
 git bisect skip [(<rev>|<range>)...]
 	mark <rev>... untestable revisions.
 git bisect next
 	find next bisection to test and check it out.
 git bisect reset [<commit>]
 	finish bisection search and go back to commit.
 git bisect visualize
 	show bisect status in gitk.
 git bisect replay <logfile>
 	replay bisection log.
 git bisect log
 	show bisect log.
 git bisect run <cmd>...
 	use <cmd>... to automatically bisect.

 Please use "git help bisect" to get the full man page.'

 OPTIONS_SPEC=
 . git-sh-setup
 . git-sh-i18n

 _x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
 _x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"

 bisect_head()
 {
 	if test -f "$GIT_DIR/BISECT_HEAD"
 	then
 		echo BISECT_HEAD
 	else
 		echo HEAD
 	fi
 }

 bisect_autostart() {
 	test -s "$GIT_DIR/BISECT_START" || {
 		gettextln "You need to start by \"git bisect start\"" >&2
 		if test -t 0
 		then
 			# TRANSLATORS: Make sure to include [Y] and [n] in your
 			# translation. The program will only accept English input
 			# at this point.
 			gettext "Do you want me to do it for you [Y/n]? " >&2
 			read yesno
 			case "$yesno" in
 			[Nn]*)
 				exit ;;
 			esac
 			bisect_start
 		else
 			exit 1
 		fi
 	}
 }

 bisect_start() {
 	#
 	# Check for one bad and then some good revisions.
 	#
 	has_double_dash=0
 	for arg; do
 		case "$arg" in --) has_double_dash=1; break ;; esac
 	done
 	orig_args=$(git rev-parse --sq-quote "$@")
 	bad_seen=0
 	eval=''
 	if test "z$(git rev-parse --is-bare-repository)" != zfalse
 	then
 		mode=--no-checkout
 	else
 		mode=''
 	fi
 	while [ $# -gt 0 ]; do
 		arg="$1"
 		case "$arg" in
 		--)
 			shift
 			break
 		;;
 		--no-checkout)
 			mode=--no-checkout
 			shift ;;
 		--*)
 			die "$(eval_gettext "unrecognised option: '\$arg'")" ;;
 		*)
 			rev=$(git rev-parse -q --verify "$arg^{commit}") || {
 				test $has_double_dash -eq 1 &&
 				die "$(eval_gettext "'\$arg' does not appear to be a valid revision")"
 				break
 			}
 			case $bad_seen in
 			0) state='bad' ; bad_seen=1 ;;
 			*) state='good' ;;
 			esac
 			eval="$eval bisect_write '$state' '$rev' 'nolog' &&"
 			shift
 			;;
 		esac
 	done

 	#
 	# Verify HEAD.
 	#
 	head=$(GIT_DIR="$GIT_DIR" git symbolic-ref -q HEAD) ||
 	head=$(GIT_DIR="$GIT_DIR" git rev-parse --verify HEAD) ||
 	die "$(gettext "Bad HEAD - I need a HEAD")"

 	#
 	# Check if we are bisecting.
 	#
 	start_head=''
 	if test -s "$GIT_DIR/BISECT_START"
 	then
 		# Reset to the rev from where we started.
 		start_head=$(cat "$GIT_DIR/BISECT_START")
 		if test "z$mode" != "z--no-checkout"
 		then
 			git checkout "$start_head" -- ||
 			die "$(eval_gettext "Checking out '\$start_head' failed. Try 'git bisect reset <valid-branch>'.")"
 		fi
 	else
 		# Get rev from where we start.
 		case "$head" in
 		refs/heads/*|$_x40)
 			# This error message should only be triggered by
 			# cogito usage, and cogito users should understand
 			# it relates to cg-seek.
 			[ -s "$GIT_DIR/head-name" ] &&
 				die "$(gettext "won't bisect on cg-seek'ed tree")"
 			start_head="${head#refs/heads/}"
 			;;
 		*)
 			die "$(gettext "Bad HEAD - strange symbolic ref")"
 			;;
 		esac
 	fi

 	#
 	# Get rid of any old bisect state.
 	#
 	bisect_clean_state || exit

 	#
 	# Change state.
 	# In case of mistaken revs or checkout error, or signals received,
 	# "bisect_auto_next" below may exit or misbehave.
 	# We have to trap this to be able to clean up using
 	# "bisect_clean_state".
 	#
 	trap 'bisect_clean_state' 0
 	trap 'exit 255' 1 2 3 15

 	#
 	# Write new start state.
 	#
 	echo "$start_head" >"$GIT_DIR/BISECT_START" && {
 		test "z$mode" != "z--no-checkout" ||
 		git update-ref --no-deref BISECT_HEAD "$start_head"
 	} &&
 	git rev-parse --sq-quote "$@" >"$GIT_DIR/BISECT_NAMES" &&
 	eval "$eval true" &&
 	echo "git bisect start$orig_args" >>"$GIT_DIR/BISECT_LOG" || exit
 	#
 	# Check if we can proceed to the next bisect state.
 	#
 	bisect_auto_next

 	trap '-' 0
 }

 bisect_write() {
 	state="$1"
 	rev="$2"
 	nolog="$3"
 	case "$state" in
 		bad)		tag="$state" ;;
 		good|skip)	tag="$state"-"$rev" ;;
 		*)		die "$(eval_gettext "Bad bisect_write argument: \$state")" ;;
 	esac
 	git update-ref "refs/bisect/$tag" "$rev" || exit
 	echo "# $state: $(git show-branch $rev)" >>"$GIT_DIR/BISECT_LOG"
 	test -n "$nolog" || echo "git bisect $state $rev" >>"$GIT_DIR/BISECT_LOG"
 }

 is_expected_rev() {
 	test -f "$GIT_DIR/BISECT_EXPECTED_REV" &&
 	test "$1" = $(cat "$GIT_DIR/BISECT_EXPECTED_REV")
 }

 check_expected_revs() {
 	for _rev in "$@"; do
 		if ! is_expected_rev "$_rev"
 		then
 			rm -f "$GIT_DIR/BISECT_ANCESTORS_OK"
 			rm -f "$GIT_DIR/BISECT_EXPECTED_REV"
 			return
 		fi
 	done
 }

 bisect_skip() {
 	all=''
 	for arg in "$@"
 	do
 		case "$arg" in
 		*..*)
 			revs=$(git rev-list "$arg") || die "$(eval_gettext "Bad rev input: \$arg")" ;;
 		*)
 			revs=$(git rev-parse --sq-quote "$arg") ;;
 		esac
 		all="$all $revs"
 	done
 	eval bisect_state 'skip' $all
 }

 bisect_state() {
 	bisect_autostart
 	state=$1
 	case "$#,$state" in
 	0,*)
 		die "$(gettext "Please call 'bisect_state' with at least one argument.")" ;;
 	1,bad|1,good|1,skip)
 		rev=$(git rev-parse --verify $(bisect_head)) ||
 			die "$(gettext "Bad rev input: $(bisect_head)")"
 		bisect_write "$state" "$rev"
 		check_expected_revs "$rev" ;;
 	2,bad|*,good|*,skip)
 		shift
 		hash_list=''
 		for rev in "$@"
 		do
 			sha=$(git rev-parse --verify "$rev^{commit}") ||
 				die "$(eval_gettext "Bad rev input: \$rev")"
 			hash_list="$hash_list $sha"
 		done
 		for rev in $hash_list
 		do
 			bisect_write "$state" "$rev"
 		done
 		check_expected_revs $hash_list ;;
 	*,bad)
 		die "$(gettext "'git bisect bad' can take only one argument.")" ;;
 	*)
 		usage ;;
 	esac
 	bisect_auto_next
 }

 bisect_next_check() {
 	missing_good= missing_bad=
 	git show-ref -q --verify refs/bisect/bad || missing_bad=t
 	test -n "$(git for-each-ref "refs/bisect/good-*")" || missing_good=t

 	case "$missing_good,$missing_bad,$1" in
 	,,*)
 		: have both good and bad - ok
 		;;
 	*,)
 		# do not have both but not asked to fail - just report.
 		false
 		;;
 	t,,good)
 		# have bad but not good.  we could bisect although
 		# this is less optimum.
 		gettextln "Warning: bisecting only with a bad commit." >&2
 		if test -t 0
 		then
 			# TRANSLATORS: Make sure to include [Y] and [n] in your
 			# translation. The program will only accept English input
 			# at this point.
 			gettext "Are you sure [Y/n]? " >&2
 			read yesno
 			case "$yesno" in [Nn]*) exit 1 ;; esac
 		fi
 		: bisect without good...
 		;;
 	*)

 		if test -s "$GIT_DIR/BISECT_START"
 		then
 			gettextln "You need to give me at least one good and one bad revision.
 (You can use \"git bisect bad\" and \"git bisect good\" for that.)" >&2
 		else
 			gettextln "You need to start by \"git bisect start\".
 You then need to give me at least one good and one bad revision.
 (You can use \"git bisect bad\" and \"git bisect good\" for that.)" >&2
 		fi
 		exit 1 ;;
 	esac
 }

 bisect_auto_next() {
 	bisect_next_check && bisect_next || :
 }

 bisect_next() {
 	case "$#" in 0) ;; *) usage ;; esac
 	bisect_autostart
 	bisect_next_check good

 	# Perform all bisection computation, display and checkout
 	git bisect--helper --next-all $(test -f "$GIT_DIR/BISECT_HEAD" && echo --no-checkout)
 	res=$?

 	# Check if we should exit because bisection is finished
 	if test $res -eq 10
 	then
 		bad_rev=$(git show-ref --hash --verify refs/bisect/bad)
 		bad_commit=$(git show-branch $bad_rev)
 		echo "# first bad commit: $bad_commit" >>"$GIT_DIR/BISECT_LOG"
 		exit 0
 	elif test $res -eq 2
 	then
 		echo "# only skipped commits left to test" >>"$GIT_DIR/BISECT_LOG"
 		good_revs=$(git for-each-ref --format="%(objectname)" "refs/bisect/good-*")
 		for skipped in $(git rev-list refs/bisect/bad --not $good_revs)
 		do
 			skipped_commit=$(git show-branch $skipped)
 			echo "# possible first bad commit: $skipped_commit" >>"$GIT_DIR/BISECT_LOG"
 		done
 		exit $res
 	fi

 	# Check for an error in the bisection process
 	test $res -ne 0 && exit $res

 	return 0
 }

 bisect_visualize() {
 	bisect_next_check fail

 	if test $# = 0
 	then
 		if test -n "${DISPLAY+set}${SESSIONNAME+set}${MSYSTEM+set}${SECURITYSESSIONID+set}" &&
 			type gitk >/dev/null 2>&1
 		then
 			set gitk
 		else
 			set git log
 		fi
 	else
 		case "$1" in
 		git*|tig) ;;
 		-*)	set git log "$@" ;;
 		*)	set git "$@" ;;
 		esac
 	fi

 	eval '"$@"' --bisect -- $(cat "$GIT_DIR/BISECT_NAMES")
 }

 bisect_reset() {
 	test -s "$GIT_DIR/BISECT_START" || {
 		gettextln "We are not bisecting."
 		return
 	}
 	case "$#" in
 	0) branch=$(cat "$GIT_DIR/BISECT_START") ;;
 	1) git rev-parse --quiet --verify "$1^{commit}" >/dev/null || {
 			invalid="$1"
 			die "$(eval_gettext "'\$invalid' is not a valid commit")"
 		}
 		branch="$1" ;;
 	*)
 		usage ;;
 	esac

 	if ! test -f "$GIT_DIR/BISECT_HEAD" && ! git checkout "$branch" --
 	then
 		die "$(eval_gettext "Could not check out original HEAD '\$branch'.
 Try 'git bisect reset <commit>'.")"
 	fi
 	bisect_clean_state
 }

 bisect_clean_state() {
 	# There may be some refs packed during bisection.
 	git for-each-ref --format='%(refname) %(objectname)' refs/bisect/\* |
 	while read ref hash
 	do
 		git update-ref -d $ref $hash || exit
 	done
 	rm -f "$GIT_DIR/BISECT_EXPECTED_REV" &&
 	rm -f "$GIT_DIR/BISECT_ANCESTORS_OK" &&
 	rm -f "$GIT_DIR/BISECT_LOG" &&
 	rm -f "$GIT_DIR/BISECT_NAMES" &&
 	rm -f "$GIT_DIR/BISECT_RUN" &&
 	# Cleanup head-name if it got left by an old version of git-bisect
 	rm -f "$GIT_DIR/head-name" &&
 	git update-ref -d --no-deref BISECT_HEAD &&
 	# clean up BISECT_START last
 	rm -f "$GIT_DIR/BISECT_START"
 }

 bisect_replay () {
 	file="$1"
 	test "$#" -eq 1 || die "$(gettext "No logfile given")"
 	test -r "$file" || die "$(eval_gettext "cannot read \$file for replaying")"
 	bisect_reset
 	while read git bisect command rev
 	do
 		test "$git $bisect" = "git bisect" || test "$git" = "git-bisect" || continue
 		if test "$git" = "git-bisect"
 		then
 			rev="$command"
 			command="$bisect"
 		fi
 		case "$command" in
 		start)
 			cmd="bisect_start $rev"
 			eval "$cmd" ;;
 		good|bad|skip)
 			bisect_write "$command" "$rev" ;;
 		*)
 			die "$(gettext "?? what are you talking about?")" ;;
 		esac
 	done <"$file"
 	bisect_auto_next
 }

 bisect_run () {
 	bisect_next_check fail

 	while true
 	do
 		command="$@"
 		eval_gettextln "running \$command"
 		"$@"
 		res=$?

 		# Check for really bad run error.
 		if [ $res -lt 0 -o $res -ge 128 ]
 		then
 			eval_gettextln "bisect run failed:
 exit code \$res from '\$command' is < 0 or >= 128" >&2
 			exit $res
 		fi

 		# Find current state depending on run success or failure.
 		# A special exit code of 125 means cannot test.
 		if [ $res -eq 125 ]
 		then
 			state='skip'
 		elif [ $res -gt 0 ]
 		then
 			state='bad'
 		else
 			state='good'
 		fi

 		# We have to use a subshell because "bisect_state" can exit.
 		( bisect_state $state >"$GIT_DIR/BISECT_RUN" )
 		res=$?

 		cat "$GIT_DIR/BISECT_RUN"

 		if sane_grep "first bad commit could be any of" "$GIT_DIR/BISECT_RUN" \
 			>/dev/null
 		then
 			gettextln "bisect run cannot continue any more" >&2
 			exit $res
 		fi

 		if [ $res -ne 0 ]
 		then
 			eval_gettextln "bisect run failed:
 'bisect_state \$state' exited with error code \$res" >&2
 			exit $res
 		fi

 		if sane_grep "is the first bad commit" "$GIT_DIR/BISECT_RUN" >/dev/null
 		then
 			gettextln "bisect run success"
 			exit 0;
 		fi

 	done
 }

 bisect_log () {
 	test -s "$GIT_DIR/BISECT_LOG" || die "$(gettext "We are not bisecting.")"
 	cat "$GIT_DIR/BISECT_LOG"
 }

 case "$#" in
 0)
 	usage ;;
 *)
 	cmd="$1"
 	shift
 	case "$cmd" in
 	help)
 		git bisect -h ;;
 	start)
 		bisect_start "$@" ;;
 	bad|good)
 		bisect_state "$cmd" "$@" ;;
 	skip)
 		bisect_skip "$@" ;;
 	next)
 		# Not sure we want "next" at the UI level anymore.
 		bisect_next "$@" ;;
 	visualize|view)
 		bisect_visualize "$@" ;;
 	reset)
 		bisect_reset "$@" ;;
 	replay)
 		bisect_replay "$@" ;;
 	log)
 		bisect_log ;;
 	run)
 		bisect_run "$@" ;;
 	*)
 		usage ;;
 	esac
 esac
	#!/bin/sh

	USAGE='[help\|start\|bad\|good\|skip\|next\|reset\|visualize\|replay\|log\|run]'
	LONG_USAGE='git bisect help
	print this long help message.
	git bisect start [--no-checkout] [<bad> [<good>...]] [--] [<pathspec>...]
	reset bisect state and start bisection.
	git bisect bad [<rev>]
	mark <rev> a known-bad revision.
	git bisect good [<rev>...]
	mark <rev>... known-good revisions.
	git bisect skip [(<rev>\|<range>)...]
	mark <rev>... untestable revisions.
	git bisect next
	find next bisection to test and check it out.
	git bisect reset [<commit>]
	finish bisection search and go back to commit.
	git bisect visualize
	show bisect status in gitk.
	git bisect replay <logfile>
	replay bisection log.
	git bisect log
	show bisect log.
	git bisect run <cmd>...
	use <cmd>... to automatically bisect.

	Please use "git help bisect" to get the full man page.'

	OPTIONS_SPEC=
	. git-sh-setup
	. git-sh-i18n

	_x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
	_x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"

	bisect_head()
	{
	if test -f "$GIT_DIR/BISECT_HEAD"
	then
	echo BISECT_HEAD
	else
	echo HEAD
	fi
	}

	bisect_autostart() {
	test -s "$GIT_DIR/BISECT_START" \|\| {
	gettextln "You need to start by \"git bisect start\"" >&2
	if test -t 0
	then
	# TRANSLATORS: Make sure to include [Y] and [n] in your
	# translation. The program will only accept English input
	# at this point.
	gettext "Do you want me to do it for you [Y/n]? " >&2
	read yesno
	case "$yesno" in
	[Nn]*)
	exit ;;
	esac
	bisect_start
	else
	exit 1
	fi
	}
	}

	bisect_start() {
	#
	# Check for one bad and then some good revisions.
	#
	has_double_dash=0
	for arg; do
	case "$arg" in --) has_double_dash=1; break ;; esac
	done
	orig_args=$(git rev-parse --sq-quote "$@")
	bad_seen=0
	eval=''
	if test "z$(git rev-parse --is-bare-repository)" != zfalse
	then
	mode=--no-checkout
	else
	mode=''
	fi
	while [ $# -gt 0 ]; do
	arg="$1"
	case "$arg" in
	--)
	shift
	break
	;;
	--no-checkout)
	mode=--no-checkout
	shift ;;
	--*)
	die "$(eval_gettext "unrecognised option: '\$arg'")" ;;
	*)
	rev=$(git rev-parse -q --verify "$arg^{commit}") \|\| {
	test $has_double_dash -eq 1 &&
	die "$(eval_gettext "'\$arg' does not appear to be a valid revision")"
	break
	}
	case $bad_seen in
	0) state='bad' ; bad_seen=1 ;;
	*) state='good' ;;
	esac
	eval="$eval bisect_write '$state' '$rev' 'nolog' &&"
	shift
	;;
	esac
	done

	#
	# Verify HEAD.
	#
	head=$(GIT_DIR="$GIT_DIR" git symbolic-ref -q HEAD) \|\|
	head=$(GIT_DIR="$GIT_DIR" git rev-parse --verify HEAD) \|\|
	die "$(gettext "Bad HEAD - I need a HEAD")"

	#
	# Check if we are bisecting.
	#
	start_head=''
	if test -s "$GIT_DIR/BISECT_START"
	then
	# Reset to the rev from where we started.
	start_head=$(cat "$GIT_DIR/BISECT_START")
	if test "z$mode" != "z--no-checkout"
	then
	git checkout "$start_head" -- \|\|
	die "$(eval_gettext "Checking out '\$start_head' failed. Try 'git bisect reset <valid-branch>'.")"
	fi
	else
	# Get rev from where we start.
	case "$head" in
	refs/heads/*\|$_x40)
	# This error message should only be triggered by
	# cogito usage, and cogito users should understand
	# it relates to cg-seek.
	[ -s "$GIT_DIR/head-name" ] &&
	die "$(gettext "won't bisect on cg-seek'ed tree")"
	start_head="${head#refs/heads/}"
	;;
	*)
	die "$(gettext "Bad HEAD - strange symbolic ref")"
	;;
	esac
	fi

	#
	# Get rid of any old bisect state.
	#
	bisect_clean_state \|\| exit

	#
	# Change state.
	# In case of mistaken revs or checkout error, or signals received,
	# "bisect_auto_next" below may exit or misbehave.
	# We have to trap this to be able to clean up using
	# "bisect_clean_state".
	#
	trap 'bisect_clean_state' 0
	trap 'exit 255' 1 2 3 15

	#
	# Write new start state.
	#
	echo "$start_head" >"$GIT_DIR/BISECT_START" && {
	test "z$mode" != "z--no-checkout" \|\|
	git update-ref --no-deref BISECT_HEAD "$start_head"
	} &&
	git rev-parse --sq-quote "$@" >"$GIT_DIR/BISECT_NAMES" &&
	eval "$eval true" &&
	echo "git bisect start$orig_args" >>"$GIT_DIR/BISECT_LOG" \|\| exit
	#
	# Check if we can proceed to the next bisect state.
	#
	bisect_auto_next

	trap '-' 0
	}

	bisect_write() {
	state="$1"
	rev="$2"
	nolog="$3"
	case "$state" in
	bad) tag="$state" ;;
	good\|skip) tag="$state"-"$rev" ;;
	*) die "$(eval_gettext "Bad bisect_write argument: \$state")" ;;
	esac
	git update-ref "refs/bisect/$tag" "$rev" \|\| exit
	echo "# $state: $(git show-branch $rev)" >>"$GIT_DIR/BISECT_LOG"
	test -n "$nolog" \|\| echo "git bisect $state $rev" >>"$GIT_DIR/BISECT_LOG"
	}

	is_expected_rev() {
	test -f "$GIT_DIR/BISECT_EXPECTED_REV" &&
	test "$1" = $(cat "$GIT_DIR/BISECT_EXPECTED_REV")
	}

	check_expected_revs() {
	for _rev in "$@"; do
	if ! is_expected_rev "$_rev"
	then
	rm -f "$GIT_DIR/BISECT_ANCESTORS_OK"
	rm -f "$GIT_DIR/BISECT_EXPECTED_REV"
	return
	fi
	done
	}

	bisect_skip() {
	all=''
	for arg in "$@"
	do
	case "$arg" in
	..)
	revs=$(git rev-list "$arg") \|\| die "$(eval_gettext "Bad rev input: \$arg")" ;;
	*)
	revs=$(git rev-parse --sq-quote "$arg") ;;
	esac
	all="$all $revs"
	done
	eval bisect_state 'skip' $all
	}

	bisect_state() {
	bisect_autostart
	state=$1
	case "$#,$state" in
	0,*)
	die "$(gettext "Please call 'bisect_state' with at least one argument.")" ;;
	1,bad\|1,good\|1,skip)
	rev=$(git rev-parse --verify $(bisect_head)) \|\|
	die "$(gettext "Bad rev input: $(bisect_head)")"
	bisect_write "$state" "$rev"
	check_expected_revs "$rev" ;;
	2,bad\|,good\|,skip)
	shift
	hash_list=''
	for rev in "$@"
	do
	sha=$(git rev-parse --verify "$rev^{commit}") \|\|
	die "$(eval_gettext "Bad rev input: \$rev")"
	hash_list="$hash_list $sha"
	done
	for rev in $hash_list
	do
	bisect_write "$state" "$rev"
	done
	check_expected_revs $hash_list ;;
	*,bad)
	die "$(gettext "'git bisect bad' can take only one argument.")" ;;
	*)
	usage ;;
	esac
	bisect_auto_next
	}

	bisect_next_check() {
	missing_good= missing_bad=
	git show-ref -q --verify refs/bisect/bad \|\| missing_bad=t
	test -n "$(git for-each-ref "refs/bisect/good-*")" \|\| missing_good=t

	case "$missing_good,$missing_bad,$1" in
	,,*)
	: have both good and bad - ok
	;;
	*,)
	# do not have both but not asked to fail - just report.
	false
	;;
	t,,good)
	# have bad but not good. we could bisect although
	# this is less optimum.
	gettextln "Warning: bisecting only with a bad commit." >&2
	if test -t 0
	then
	# TRANSLATORS: Make sure to include [Y] and [n] in your
	# translation. The program will only accept English input
	# at this point.
	gettext "Are you sure [Y/n]? " >&2
	read yesno
	case "$yesno" in [Nn]*) exit 1 ;; esac
	fi
	: bisect without good...
	;;
	*)

	if test -s "$GIT_DIR/BISECT_START"
	then
	gettextln "You need to give me at least one good and one bad revision.
	(You can use \"git bisect bad\" and \"git bisect good\" for that.)" >&2
	else
	gettextln "You need to start by \"git bisect start\".
	You then need to give me at least one good and one bad revision.
	(You can use \"git bisect bad\" and \"git bisect good\" for that.)" >&2
	fi
	exit 1 ;;
	esac
	}

	bisect_auto_next() {
	bisect_next_check && bisect_next \|\| :
	}

	bisect_next() {
	case "$#" in 0) ;; *) usage ;; esac
	bisect_autostart
	bisect_next_check good

	# Perform all bisection computation, display and checkout
	git bisect--helper --next-all $(test -f "$GIT_DIR/BISECT_HEAD" && echo --no-checkout)
	res=$?

	# Check if we should exit because bisection is finished
	if test $res -eq 10
	then
	bad_rev=$(git show-ref --hash --verify refs/bisect/bad)
	bad_commit=$(git show-branch $bad_rev)
	echo "# first bad commit: $bad_commit" >>"$GIT_DIR/BISECT_LOG"
	exit 0
	elif test $res -eq 2
	then
	echo "# only skipped commits left to test" >>"$GIT_DIR/BISECT_LOG"
	good_revs=$(git for-each-ref --format="%(objectname)" "refs/bisect/good-*")
	for skipped in $(git rev-list refs/bisect/bad --not $good_revs)
	do
	skipped_commit=$(git show-branch $skipped)
	echo "# possible first bad commit: $skipped_commit" >>"$GIT_DIR/BISECT_LOG"
	done
	exit $res
	fi

	# Check for an error in the bisection process
	test $res -ne 0 && exit $res

	return 0
	}

	bisect_visualize() {
	bisect_next_check fail

	if test $# = 0
	then
	if test -n "${DISPLAY+set}${SESSIONNAME+set}${MSYSTEM+set}${SECURITYSESSIONID+set}" &&
	type gitk >/dev/null 2>&1
	then
	set gitk
	else
	set git log
	fi
	else
	case "$1" in
	git*\|tig) ;;
	-*) set git log "$@" ;;
	*) set git "$@" ;;
	esac
	fi

	eval '"$@"' --bisect -- $(cat "$GIT_DIR/BISECT_NAMES")
	}

	bisect_reset() {
	test -s "$GIT_DIR/BISECT_START" \|\| {
	gettextln "We are not bisecting."
	return
	}
	case "$#" in
	0) branch=$(cat "$GIT_DIR/BISECT_START") ;;
	1) git rev-parse --quiet --verify "$1^{commit}" >/dev/null \|\| {
	invalid="$1"
	die "$(eval_gettext "'\$invalid' is not a valid commit")"
	}
	branch="$1" ;;
	*)
	usage ;;
	esac

	if ! test -f "$GIT_DIR/BISECT_HEAD" && ! git checkout "$branch" --
	then
	die "$(eval_gettext "Could not check out original HEAD '\$branch'.
	Try 'git bisect reset <commit>'.")"
	fi
	bisect_clean_state
	}

	bisect_clean_state() {
	# There may be some refs packed during bisection.
	git for-each-ref --format='%(refname) %(objectname)' refs/bisect/\* \|
	while read ref hash
	do
	git update-ref -d $ref $hash \|\| exit
	done
	rm -f "$GIT_DIR/BISECT_EXPECTED_REV" &&
	rm -f "$GIT_DIR/BISECT_ANCESTORS_OK" &&
	rm -f "$GIT_DIR/BISECT_LOG" &&
	rm -f "$GIT_DIR/BISECT_NAMES" &&
	rm -f "$GIT_DIR/BISECT_RUN" &&
	# Cleanup head-name if it got left by an old version of git-bisect
	rm -f "$GIT_DIR/head-name" &&
	git update-ref -d --no-deref BISECT_HEAD &&
	# clean up BISECT_START last
	rm -f "$GIT_DIR/BISECT_START"
	}

	bisect_replay () {
	file="$1"
	test "$#" -eq 1 \|\| die "$(gettext "No logfile given")"
	test -r "$file" \|\| die "$(eval_gettext "cannot read \$file for replaying")"
	bisect_reset
	while read git bisect command rev
	do
	test "$git $bisect" = "git bisect" \|\| test "$git" = "git-bisect" \|\| continue
	if test "$git" = "git-bisect"
	then
	rev="$command"
	command="$bisect"
	fi
	case "$command" in
	start)
	cmd="bisect_start $rev"
	eval "$cmd" ;;
	good\|bad\|skip)
	bisect_write "$command" "$rev" ;;
	*)
	die "$(gettext "?? what are you talking about?")" ;;
	esac
	done <"$file"
	bisect_auto_next
	}

	bisect_run () {
	bisect_next_check fail

	while true
	do
	command="$@"
	eval_gettextln "running \$command"
	"$@"
	res=$?

	# Check for really bad run error.
	if [ $res -lt 0 -o $res -ge 128 ]
	then
	eval_gettextln "bisect run failed:
	exit code \$res from '\$command' is < 0 or >= 128" >&2
	exit $res
	fi

	# Find current state depending on run success or failure.
	# A special exit code of 125 means cannot test.
	if [ $res -eq 125 ]
	then
	state='skip'
	elif [ $res -gt 0 ]
	then
	state='bad'
	else
	state='good'
	fi

	# We have to use a subshell because "bisect_state" can exit.
	( bisect_state $state >"$GIT_DIR/BISECT_RUN" )
	res=$?

	cat "$GIT_DIR/BISECT_RUN"

	if sane_grep "first bad commit could be any of" "$GIT_DIR/BISECT_RUN" \
	>/dev/null
	then
	gettextln "bisect run cannot continue any more" >&2
	exit $res
	fi

	if [ $res -ne 0 ]
	then
	eval_gettextln "bisect run failed:
	'bisect_state \$state' exited with error code \$res" >&2
	exit $res
	fi

	if sane_grep "is the first bad commit" "$GIT_DIR/BISECT_RUN" >/dev/null
	then
	gettextln "bisect run success"
	exit 0;
	fi

	done
	}

	bisect_log () {
	test -s "$GIT_DIR/BISECT_LOG" \|\| die "$(gettext "We are not bisecting.")"
	cat "$GIT_DIR/BISECT_LOG"
	}

	case "$#" in
	0)
	usage ;;
	*)
	cmd="$1"
	shift
	case "$cmd" in
	help)
	git bisect -h ;;
	start)
	bisect_start "$@" ;;
	bad\|good)
	bisect_state "$cmd" "$@" ;;
	skip)
	bisect_skip "$@" ;;
	next)
	# Not sure we want "next" at the UI level anymore.
	bisect_next "$@" ;;
	visualize\|view)
	bisect_visualize "$@" ;;
	reset)
	bisect_reset "$@" ;;
	replay)
	bisect_replay "$@" ;;
	log)
	bisect_log ;;
	run)
	bisect_run "$@" ;;
	*)
	usage ;;
	esac
	esac