[thirdparty/git.git] / git-filter-branch.sh

#!/bin/sh
#
# Rewrite revision history
# Copyright (c) Petr Baudis, 2006
# Minimal changes to "port" it to core-git (c) Johannes Schindelin, 2007
#
# Lets you rewrite the revision history of the current branch, creating
# a new branch. You can specify a number of filters to modify the commits,
# files and trees.

# The following functions will also be available in the commit filter:

functions=$(cat << \EOF
warn () {
        echo "$*" >&2
}

map()
{
	# if it was not rewritten, take the original
	if test -r "$workdir/../map/$1"
	then
		cat "$workdir/../map/$1"
	else
		echo "$1"
	fi
}

# if you run 'skip_commit "$@"' in a commit filter, it will print
# the (mapped) parents, effectively skipping the commit.

skip_commit()
{
	shift;
	while [ -n "$1" ];
	do
		shift;
		map "$1";
		shift;
	done;
}

# override die(): this version puts in an extra line break, so that
# the progress is still visible

die()
{
	echo >&2
	echo "$*" >&2
	exit 1
}
EOF
)

eval "$functions"

# When piped a commit, output a script to set the ident of either
# "author" or "committer

set_ident () {
	lid="$(echo "$1" | tr "A-Z" "a-z")"
	uid="$(echo "$1" | tr "a-z" "A-Z")"
	pick_id_script='
		/^'$lid' /{
			s/'\''/'\''\\'\'\''/g
			h
			s/^'$lid' \([^<]*\) <[^>]*> .*$/\1/
			s/'\''/'\''\'\'\''/g
			s/.*/export GIT_'$uid'_NAME='\''&'\''/p

			g
			s/^'$lid' [^<]* <\([^>]*\)> .*$/\1/
			s/'\''/'\''\'\'\''/g
			s/.*/export GIT_'$uid'_EMAIL='\''&'\''/p

			g
			s/^'$lid' [^<]* <[^>]*> \(.*\)$/\1/
			s/'\''/'\''\'\'\''/g
			s/.*/export GIT_'$uid'_DATE='\''&'\''/p

			q
		}
	'

	LANG=C LC_ALL=C sed -ne "$pick_id_script"
	# Ensure non-empty id name.
	echo "[ -n \"\$GIT_${uid}_NAME\" ] || export GIT_${uid}_NAME=\"\${GIT_${uid}_EMAIL%%@*}\""
}

USAGE="[--env-filter <command>] [--tree-filter <command>] \
[--index-filter <command>] [--parent-filter <command>] \
[--msg-filter <command>] [--commit-filter <command>] \
[--tag-name-filter <command>] [--subdirectory-filter <directory>] \
[--original <namespace>] [-d <directory>] [-f | --force] \
[<rev-list options>...]"

OPTIONS_SPEC=
. git-sh-setup

git diff-files --quiet &&
	git diff-index --cached --quiet HEAD -- ||
	die "Cannot rewrite branch(es) with a dirty working directory."

tempdir=.git-rewrite
filter_env=
filter_tree=
filter_index=
filter_parent=
filter_msg=cat
filter_commit='git commit-tree "$@"'
filter_tag_name=
filter_subdir=
orig_namespace=refs/original/
force=
while :
do
	test $# = 0 && usage
	case "$1" in
	--)
		shift
		break
		;;
	--force|-f)
		shift
		force=t
		continue
		;;
	-*)
		;;
	*)
		break;
	esac

	# all switches take one argument
	ARG="$1"
	case "$#" in 1) usage ;; esac
	shift
	OPTARG="$1"
	shift

	case "$ARG" in
	-d)
		tempdir="$OPTARG"
		;;
	--env-filter)
		filter_env="$OPTARG"
		;;
	--tree-filter)
		filter_tree="$OPTARG"
		;;
	--index-filter)
		filter_index="$OPTARG"
		;;
	--parent-filter)
		filter_parent="$OPTARG"
		;;
	--msg-filter)
		filter_msg="$OPTARG"
		;;
	--commit-filter)
		filter_commit="$functions; $OPTARG"
		;;
	--tag-name-filter)
		filter_tag_name="$OPTARG"
		;;
	--subdirectory-filter)
		filter_subdir="$OPTARG"
		;;
	--original)
		orig_namespace=$(expr "$OPTARG/" : '\(.*[^/]\)/*$')/
		;;
	*)
		usage
		;;
	esac
done

case "$force" in
t)
	rm -rf "$tempdir"
;;
'')
	test -d "$tempdir" &&
		die "$tempdir already exists, please remove it"
esac
mkdir -p "$tempdir/t" &&
tempdir="$(cd "$tempdir"; pwd)" &&
cd "$tempdir/t" &&
workdir="$(pwd)" ||
die ""

# Make sure refs/original is empty
git for-each-ref > "$tempdir"/backup-refs
while read sha1 type name
do
	case "$force,$name" in
	,$orig_namespace*)
		die "Namespace $orig_namespace not empty"
	;;
	t,$orig_namespace*)
		git update-ref -d "$name" $sha1
	;;
	esac
done < "$tempdir"/backup-refs

ORIG_GIT_DIR="$GIT_DIR"
ORIG_GIT_WORK_TREE="$GIT_WORK_TREE"
ORIG_GIT_INDEX_FILE="$GIT_INDEX_FILE"
export GIT_DIR GIT_WORK_TREE=.

# These refs should be updated if their heads were rewritten

git rev-parse --revs-only --symbolic "$@" |
while read ref
do
	# normalize ref
	case "$ref" in
	HEAD)
		ref="$(git symbolic-ref "$ref")"
	;;
	refs/*)
	;;
	*)
		ref="$(git for-each-ref --format='%(refname)' |
			grep /"$ref")"
	esac

	git check-ref-format "$ref" && echo "$ref"
done > "$tempdir"/heads

test -s "$tempdir"/heads ||
	die "Which ref do you want to rewrite?"

export GIT_INDEX_FILE="$(pwd)/../index"
git read-tree || die "Could not seed the index"

ret=0

# map old->new commit ids for rewriting parents
mkdir ../map || die "Could not create map/ directory"

case "$filter_subdir" in
"")
	git rev-list --reverse --topo-order --default HEAD \
		--parents "$@"
	;;
*)
	git rev-list --reverse --topo-order --default HEAD \
		--parents --full-history "$@" -- "$filter_subdir"
esac > ../revs || die "Could not get the commits"
commits=$(wc -l <../revs | tr -d " ")

test $commits -eq 0 && die "Found nothing to rewrite"

# Rewrite the commits

i=0
while read commit parents; do
	i=$(($i+1))
	printf "\rRewrite $commit ($i/$commits)"

	case "$filter_subdir" in
	"")
		git read-tree -i -m $commit
		;;
	*)
		git read-tree -i -m $commit:"$filter_subdir"
	esac || die "Could not initialize the index"

	export GIT_COMMIT=$commit
	git cat-file commit "$commit" >../commit ||
		die "Cannot read commit $commit"

	eval "$(set_ident AUTHOR <../commit)" ||
		die "setting author failed for commit $commit"
	eval "$(set_ident COMMITTER <../commit)" ||
		die "setting committer failed for commit $commit"
	eval "$filter_env" < /dev/null ||
		die "env filter failed: $filter_env"

	if [ "$filter_tree" ]; then
		git checkout-index -f -u -a ||
			die "Could not checkout the index"
		# files that $commit removed are now still in the working tree;
		# remove them, else they would be added again
		git ls-files -z --others | xargs -0 rm -f
		eval "$filter_tree" < /dev/null ||
			die "tree filter failed: $filter_tree"

		git diff-index -r $commit | cut -f 2- | tr '\n' '\0' | \
			xargs -0 git update-index --add --replace --remove
		git ls-files -z --others | \
			xargs -0 git update-index --add --replace --remove
	fi

	eval "$filter_index" < /dev/null ||
		die "index filter failed: $filter_index"

	parentstr=
	for parent in $parents; do
		for reparent in $(map "$parent"); do
			parentstr="$parentstr -p $reparent"
		done
	done
	if [ "$filter_parent" ]; then
		parentstr="$(echo "$parentstr" | eval "$filter_parent")" ||
				die "parent filter failed: $filter_parent"
	fi

	sed -e '1,/^$/d' <../commit | \
		eval "$filter_msg" > ../message ||
			die "msg filter failed: $filter_msg"
	sh -c "$filter_commit" "git commit-tree" \
		$(git write-tree) $parentstr < ../message > ../map/$commit
done <../revs

# In case of a subdirectory filter, it is possible that a specified head
# is not in the set of rewritten commits, because it was pruned by the
# revision walker.  Fix it by mapping these heads to the next rewritten
# ancestor(s), i.e. the boundaries in the set of rewritten commits.

# NEEDSWORK: we should sort the unmapped refs topologically first
while read ref
do
	sha1=$(git rev-parse "$ref"^0)
	test -f "$workdir"/../map/$sha1 && continue
	# Assign the boundarie(s) in the set of rewritten commits
	# as the replacement commit(s).
	# (This would look a bit nicer if --not --stdin worked.)
	for p in $( (cd "$workdir"/../map; ls | sed "s/^/^/") |
		git rev-list $ref --boundary --stdin |
		sed -n "s/^-//p")
	do
		map $p >> "$workdir"/../map/$sha1
	done
done < "$tempdir"/heads

# Finally update the refs

_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"
count=0
echo
while read ref
do
	# avoid rewriting a ref twice
	test -f "$orig_namespace$ref" && continue

	sha1=$(git rev-parse "$ref"^0)
	rewritten=$(map $sha1)

	test $sha1 = "$rewritten" &&
		warn "WARNING: Ref '$ref' is unchanged" &&
		continue

	case "$rewritten" in
	'')
		echo "Ref '$ref' was deleted"
		git update-ref -m "filter-branch: delete" -d "$ref" $sha1 ||
			die "Could not delete $ref"
	;;
	$_x40)
		echo "Ref '$ref' was rewritten"
		git update-ref -m "filter-branch: rewrite" \
				"$ref" $rewritten $sha1 ||
			die "Could not rewrite $ref"
	;;
	*)
		# NEEDSWORK: possibly add -Werror, making this an error
		warn "WARNING: '$ref' was rewritten into multiple commits:"
		warn "$rewritten"
		warn "WARNING: Ref '$ref' points to the first one now."
		rewritten=$(echo "$rewritten" | head -n 1)
		git update-ref -m "filter-branch: rewrite to first" \
				"$ref" $rewritten $sha1 ||
			die "Could not rewrite $ref"
	;;
	esac
	git update-ref -m "filter-branch: backup" "$orig_namespace$ref" $sha1
	count=$(($count+1))
done < "$tempdir"/heads

# TODO: This should possibly go, with the semantics that all positive given
#       refs are updated, and their original heads stored in refs/original/
# Filter tags

if [ "$filter_tag_name" ]; then
	git for-each-ref --format='%(objectname) %(objecttype) %(refname)' refs/tags |
	while read sha1 type ref; do
		ref="${ref#refs/tags/}"
		# XXX: Rewrite tagged trees as well?
		if [ "$type" != "commit" -a "$type" != "tag" ]; then
			continue;
		fi

		if [ "$type" = "tag" ]; then
			# Dereference to a commit
			sha1t="$sha1"
			sha1="$(git rev-parse "$sha1"^{commit} 2>/dev/null)" || continue
		fi

		[ -f "../map/$sha1" ] || continue
		new_sha1="$(cat "../map/$sha1")"
		export GIT_COMMIT="$sha1"
		new_ref="$(echo "$ref" | eval "$filter_tag_name")" ||
			die "tag name filter failed: $filter_tag_name"

		echo "$ref -> $new_ref ($sha1 -> $new_sha1)"

		if [ "$type" = "tag" ]; then
			# Warn that we are not rewriting the tag object itself.
			warn "unreferencing tag object $sha1t"
		fi

		git update-ref "refs/tags/$new_ref" "$new_sha1" ||
			die "Could not write tag $new_ref"
	done
fi

cd ../..
rm -rf "$tempdir"
echo
test $count -gt 0 && echo "These refs were rewritten:"
git show-ref | grep ^"$orig_namespace"

unset GIT_DIR GIT_WORK_TREE GIT_INDEX_FILE
test -z "$ORIG_GIT_DIR" || GIT_DIR="$ORIG_GIT_DIR" && export GIT_DIR
test -z "$ORIG_GIT_WORK_TREE" || GIT_WORK_TREE="$ORIG_GIT_WORK_TREE" &&
	export GIT_WORK_TREE
test -z "$ORIG_GIT_INDEX_FILE" || GIT_INDEX_FILE="$ORIG_GIT_INDEX_FILE" &&
	export GIT_INDEX_FILE
git read-tree -u -m HEAD

exit $ret
Commit	Line	Data
6f6826c5 JS	1	#!/bin/sh
	2	#
	3	# Rewrite revision history
	4	# Copyright (c) Petr Baudis, 2006
	5	# Minimal changes to "port" it to core-git (c) Johannes Schindelin, 2007
	6	#
c401b33c JS	7	# Lets you rewrite the revision history of the current branch, creating
	8	# a new branch. You can specify a number of filters to modify the commits,
	9	# files and trees.
6f6826c5	10
16ed34ad JS	11	# The following functions will also be available in the commit filter:
	12
	13	functions=$(cat << \EOF
b5669a05 SP	14	warn () {
	15	echo "$*" >&2
	16	}
	17
6f6826c5 JS	18	map()
6f6826c5 JS	19	{
3520e1e8	20	# if it was not rewritten, take the original
c57a3494 JS	21	if test -r "$workdir/../map/$1"
	22	then
	23	cat "$workdir/../map/$1"
	24	else
	25	echo "$1"
	26	fi
6f6826c5 JS	27	}
6f6826c5 JS	28
f95eef15 JS	29	# if you run 'skip_commit "$@"' in a commit filter, it will print
	30	# the (mapped) parents, effectively skipping the commit.
	31
	32	skip_commit()
	33	{
	34	shift;
	35	while [ -n "$1" ];
	36	do
	37	shift;
	38	map "$1";
	39	shift;
	40	done;
	41	}
	42
8c1ce0f4 JS	43	# override die(): this version puts in an extra line break, so that
	44	# the progress is still visible
	45
	46	die()
	47	{
	48	echo >&2
	49	echo "$*" >&2
	50	exit 1
	51	}
16ed34ad JS	52	EOF
	53	)
	54
	55	eval "$functions"
8c1ce0f4	56
6f6826c5 JS	57	# When piped a commit, output a script to set the ident of either
	58	# "author" or "committer
	59
	60	set_ident () {
	61	lid="$(echo "$1" \| tr "A-Z" "a-z")"
	62	uid="$(echo "$1" \| tr "a-z" "A-Z")"
	63	pick_id_script='
	64	/^'$lid' /{
	65	s/'\''/'\''\\'\'\''/g
	66	h
	67	s/^'$lid' \([^<]\) <[^>]> .*$/\1/
	68	s/'\''/'\''\'\'\''/g
	69	s/.*/export GIT_'$uid'_NAME='\''&'\''/p
	70
	71	g
	72	s/^'$lid' [^<]* <\([^>]\)> .$/\1/
	73	s/'\''/'\''\'\'\''/g
	74	s/.*/export GIT_'$uid'_EMAIL='\''&'\''/p
	75
	76	g
	77	s/^'$lid' [^<]* <[^>]> \(.\)$/\1/
	78	s/'\''/'\''\'\'\''/g
	79	s/.*/export GIT_'$uid'_DATE='\''&'\''/p
	80
	81	q
	82	}
	83	'
	84
	85	LANG=C LC_ALL=C sed -ne "$pick_id_script"
	86	# Ensure non-empty id name.
	87	echo "[ -n \"\$GIT_${uid}_NAME\" ] \|\| export GIT_${uid}_NAME=\"\${GIT_${uid}_EMAIL%%@*}\""
	88	}
	89
7e0f1704 JS	90	USAGE="[--env-filter <command>] [--tree-filter <command>] \
	91	[--index-filter <command>] [--parent-filter <command>] \
	92	[--msg-filter <command>] [--commit-filter <command>] \
	93	[--tag-name-filter <command>] [--subdirectory-filter <directory>] \
	94	[--original <namespace>] [-d <directory>] [-f \| --force] \
	95	[<rev-list options>...]"
	96
8f321a39	97	OPTIONS_SPEC=
7e0f1704 JS	98	. git-sh-setup
7e0f1704 JS	99
46eb449c	100	git diff-files --quiet &&
38762c47	101	git diff-index --cached --quiet HEAD -- \|\|
46eb449c JS	102	die "Cannot rewrite branch(es) with a dirty working directory."
46eb449c JS	103
6f6826c5	104	tempdir=.git-rewrite
6f6826c5 JS	105	filter_env=
	106	filter_tree=
	107	filter_index=
	108	filter_parent=
	109	filter_msg=cat
5be60078	110	filter_commit='git commit-tree "$@"'
6f6826c5	111	filter_tag_name=
685ef546	112	filter_subdir=
dfd05e38 JS	113	orig_namespace=refs/original/
dfd05e38 JS	114	force=
822f7c73	115	while :
6f6826c5	116	do
822f7c73	117	test $# = 0 && usage
6f6826c5 JS	118	case "$1" in
	119	--)
	120	shift
	121	break
	122	;;
dfd05e38 JS	123	--force\|-f)
	124	shift
	125	force=t
	126	continue
	127	;;
6f6826c5 JS	128	-*)
	129	;;
	130	*)
	131	break;
	132	esac
	133
	134	# all switches take one argument
	135	ARG="$1"
	136	case "$#" in 1) usage ;; esac
	137	shift
	138	OPTARG="$1"
	139	shift
	140
	141	case "$ARG" in
	142	-d)
	143	tempdir="$OPTARG"
	144	;;
6f6826c5 JS	145	--env-filter)
	146	filter_env="$OPTARG"
	147	;;
	148	--tree-filter)
	149	filter_tree="$OPTARG"
	150	;;
	151	--index-filter)
	152	filter_index="$OPTARG"
	153	;;
	154	--parent-filter)
	155	filter_parent="$OPTARG"
	156	;;
	157	--msg-filter)
	158	filter_msg="$OPTARG"
	159	;;
	160	--commit-filter)
16ed34ad	161	filter_commit="$functions; $OPTARG"
6f6826c5 JS	162	;;
	163	--tag-name-filter)
	164	filter_tag_name="$OPTARG"
	165	;;
685ef546 JS	166	--subdirectory-filter)
	167	filter_subdir="$OPTARG"
	168	;;
dfd05e38	169	--original)
55ced83d	170	orig_namespace=$(expr "$OPTARG/" : '\(.[^/]\)/$')/
dfd05e38	171	;;
6f6826c5 JS	172	*)
	173	usage
	174	;;
	175	esac
	176	done
	177
dfd05e38 JS	178	case "$force" in
	179	t)
	180	rm -rf "$tempdir"
	181	;;
	182	'')
	183	test -d "$tempdir" &&
	184	die "$tempdir already exists, please remove it"
	185	esac
af580e9c	186	mkdir -p "$tempdir/t" &&
dfd05e38	187	tempdir="$(cd "$tempdir"; pwd)" &&
af580e9c JS	188	cd "$tempdir/t" &&
	189	workdir="$(pwd)" \|\|
	190	die ""
6f6826c5	191
dfd05e38 JS	192	# Make sure refs/original is empty
	193	git for-each-ref > "$tempdir"/backup-refs
	194	while read sha1 type name
	195	do
	196	case "$force,$name" in
	197	,$orig_namespace*)
	198	die "Namespace $orig_namespace not empty"
	199	;;
	200	t,$orig_namespace*)
	201	git update-ref -d "$name" $sha1
	202	;;
	203	esac
	204	done < "$tempdir"/backup-refs
	205
46eb449c JS	206	ORIG_GIT_DIR="$GIT_DIR"
	207	ORIG_GIT_WORK_TREE="$GIT_WORK_TREE"
	208	ORIG_GIT_INDEX_FILE="$GIT_INDEX_FILE"
9489d0f1	209	export GIT_DIR GIT_WORK_TREE=.
6f6826c5	210
dfd05e38 JS	211	# These refs should be updated if their heads were rewritten
	212
	213	git rev-parse --revs-only --symbolic "$@" \|
	214	while read ref
	215	do
	216	# normalize ref
	217	case "$ref" in
	218	HEAD)
	219	ref="$(git symbolic-ref "$ref")"
	220	;;
	221	refs/*)
	222	;;
	223	*)
	224	ref="$(git for-each-ref --format='%(refname)' \|
	225	grep /"$ref")"
	226	esac
	227
	228	git check-ref-format "$ref" && echo "$ref"
	229	done > "$tempdir"/heads
	230
	231	test -s "$tempdir"/heads \|\|
	232	die "Which ref do you want to rewrite?"
	233
6f6826c5	234	export GIT_INDEX_FILE="$(pwd)/../index"
af580e9c	235	git read-tree \|\| die "Could not seed the index"
6f6826c5 JS	236
	237	ret=0
	238
af580e9c JS	239	# map old->new commit ids for rewriting parents
af580e9c JS	240	mkdir ../map \|\| die "Could not create map/ directory"
6f6826c5	241
685ef546 JS	242	case "$filter_subdir" in
685ef546 JS	243	"")
5be60078	244	git rev-list --reverse --topo-order --default HEAD \
813b4734	245	--parents "$@"
685ef546 JS	246	;;
685ef546 JS	247	*)
5be60078	248	git rev-list --reverse --topo-order --default HEAD \
cfabd6ee	249	--parents --full-history "$@" -- "$filter_subdir"
af580e9c	250	esac > ../revs \|\| die "Could not get the commits"
9d6f220c	251	commits=$(wc -l <../revs \| tr -d " ")
6f6826c5 JS	252
	253	test $commits -eq 0 && die "Found nothing to rewrite"
	254
dfd05e38 JS	255	# Rewrite the commits
dfd05e38 JS	256
6f6826c5	257	i=0
813b4734	258	while read commit parents; do
c12764b8	259	i=$(($i+1))
5efb48b5	260	printf "\rRewrite $commit ($i/$commits)"
6f6826c5	261
685ef546 JS	262	case "$filter_subdir" in
685ef546 JS	263	"")
5be60078	264	git read-tree -i -m $commit
685ef546 JS	265	;;
685ef546 JS	266	*)
5be60078	267	git read-tree -i -m $commit:"$filter_subdir"
af580e9c	268	esac \|\| die "Could not initialize the index"
6f6826c5 JS	269
6f6826c5 JS	270	export GIT_COMMIT=$commit
af580e9c JS	271	git cat-file commit "$commit" >../commit \|\|
af580e9c JS	272	die "Cannot read commit $commit"
6f6826c5	273
8c1ce0f4 JS	274	eval "$(set_ident AUTHOR <../commit)" \|\|
	275	die "setting author failed for commit $commit"
	276	eval "$(set_ident COMMITTER <../commit)" \|\|
	277	die "setting committer failed for commit $commit"
	278	eval "$filter_env" < /dev/null \|\|
	279	die "env filter failed: $filter_env"
6f6826c5 JS	280
6f6826c5 JS	281	if [ "$filter_tree" ]; then
af580e9c JS	282	git checkout-index -f -u -a \|\|
af580e9c JS	283	die "Could not checkout the index"
6f6826c5 JS	284	# files that $commit removed are now still in the working tree;
6f6826c5 JS	285	# remove them, else they would be added again
5be60078	286	git ls-files -z --others \| xargs -0 rm -f
8c1ce0f4 JS	287	eval "$filter_tree" < /dev/null \|\|
	288	die "tree filter failed: $filter_tree"
	289
5be60078 JH	290	git diff-index -r $commit \| cut -f 2- \| tr '\n' '\0' \| \
	291	xargs -0 git update-index --add --replace --remove
	292	git ls-files -z --others \| \
	293	xargs -0 git update-index --add --replace --remove
6f6826c5 JS	294	fi
6f6826c5 JS	295
8c1ce0f4 JS	296	eval "$filter_index" < /dev/null \|\|
8c1ce0f4 JS	297	die "index filter failed: $filter_index"
6f6826c5 JS	298
6f6826c5 JS	299	parentstr=
813b4734	300	for parent in $parents; do
3520e1e8 JS	301	for reparent in $(map "$parent"); do
	302	parentstr="$parentstr -p $reparent"
	303	done
6f6826c5 JS	304	done
6f6826c5 JS	305	if [ "$filter_parent" ]; then
8c1ce0f4 JS	306	parentstr="$(echo "$parentstr" \| eval "$filter_parent")" \|\|
8c1ce0f4 JS	307	die "parent filter failed: $filter_parent"
6f6826c5 JS	308	fi
	309
	310	sed -e '1,/^$/d' <../commit \| \
8c1ce0f4 JS	311	eval "$filter_msg" > ../message \|\|
	312	die "msg filter failed: $filter_msg"
	313	sh -c "$filter_commit" "git commit-tree" \
	314	$(git write-tree) $parentstr < ../message > ../map/$commit
6f6826c5 JS	315	done <../revs
6f6826c5 JS	316
dfd05e38 JS	317	# In case of a subdirectory filter, it is possible that a specified head
	318	# is not in the set of rewritten commits, because it was pruned by the
	319	# revision walker. Fix it by mapping these heads to the next rewritten
	320	# ancestor(s), i.e. the boundaries in the set of rewritten commits.
	321
	322	# NEEDSWORK: we should sort the unmapped refs topologically first
	323	while read ref
	324	do
	325	sha1=$(git rev-parse "$ref"^0)
	326	test -f "$workdir"/../map/$sha1 && continue
	327	# Assign the boundarie(s) in the set of rewritten commits
	328	# as the replacement commit(s).
	329	# (This would look a bit nicer if --not --stdin worked.)
24d00634	330	for p in $( (cd "$workdir"/../map; ls \| sed "s/^/^/") \|
dfd05e38 JS	331	git rev-list $ref --boundary --stdin \|
	332	sed -n "s/^-//p")
	333	do
	334	map $p >> "$workdir"/../map/$sha1
	335	done
	336	done < "$tempdir"/heads
	337
	338	# Finally update the refs
	339
	340	_x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
	341	_x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
	342	count=0
	343	echo
	344	while read ref
	345	do
	346	# avoid rewriting a ref twice
	347	test -f "$orig_namespace$ref" && continue
	348
	349	sha1=$(git rev-parse "$ref"^0)
	350	rewritten=$(map $sha1)
	351
	352	test $sha1 = "$rewritten" &&
	353	warn "WARNING: Ref '$ref' is unchanged" &&
	354	continue
	355
	356	case "$rewritten" in
	357	'')
	358	echo "Ref '$ref' was deleted"
	359	git update-ref -m "filter-branch: delete" -d "$ref" $sha1 \|\|
	360	die "Could not delete $ref"
98409060	361	;;
dfd05e38 JS	362	$_x40)
	363	echo "Ref '$ref' was rewritten"
	364	git update-ref -m "filter-branch: rewrite" \
	365	"$ref" $rewritten $sha1 \|\|
	366	die "Could not rewrite $ref"
98409060	367	;;
dfd05e38 JS	368	*)
	369	# NEEDSWORK: possibly add -Werror, making this an error
	370	warn "WARNING: '$ref' was rewritten into multiple commits:"
	371	warn "$rewritten"
	372	warn "WARNING: Ref '$ref' points to the first one now."
	373	rewritten=$(echo "$rewritten" \| head -n 1)
	374	git update-ref -m "filter-branch: rewrite to first" \
	375	"$ref" $rewritten $sha1 \|\|
	376	die "Could not rewrite $ref"
	377	;;
	378	esac
	379	git update-ref -m "filter-branch: backup" "$orig_namespace$ref" $sha1
	380	count=$(($count+1))
	381	done < "$tempdir"/heads
	382
	383	# TODO: This should possibly go, with the semantics that all positive given
	384	# refs are updated, and their original heads stored in refs/original/
	385	# Filter tags
6f6826c5 JS	386
6f6826c5 JS	387	if [ "$filter_tag_name" ]; then
5be60078	388	git for-each-ref --format='%(objectname) %(objecttype) %(refname)' refs/tags \|
6f6826c5 JS	389	while read sha1 type ref; do
	390	ref="${ref#refs/tags/}"
	391	# XXX: Rewrite tagged trees as well?
	392	if [ "$type" != "commit" -a "$type" != "tag" ]; then
	393	continue;
	394	fi
	395
	396	if [ "$type" = "tag" ]; then
	397	# Dereference to a commit
	398	sha1t="$sha1"
5be60078	399	sha1="$(git rev-parse "$sha1"^{commit} 2>/dev/null)" \|\| continue
6f6826c5 JS	400	fi
	401
	402	[ -f "../map/$sha1" ] \|\| continue
	403	new_sha1="$(cat "../map/$sha1")"
	404	export GIT_COMMIT="$sha1"
8c1ce0f4 JS	405	new_ref="$(echo "$ref" \| eval "$filter_tag_name")" \|\|
8c1ce0f4 JS	406	die "tag name filter failed: $filter_tag_name"
6f6826c5 JS	407
	408	echo "$ref -> $new_ref ($sha1 -> $new_sha1)"
	409
	410	if [ "$type" = "tag" ]; then
	411	# Warn that we are not rewriting the tag object itself.
	412	warn "unreferencing tag object $sha1t"
	413	fi
	414
af580e9c JS	415	git update-ref "refs/tags/$new_ref" "$new_sha1" \|\|
af580e9c JS	416	die "Could not write tag $new_ref"
6f6826c5 JS	417	done
	418	fi
	419
	420	cd ../..
	421	rm -rf "$tempdir"
dfd05e38 JS	422	echo
	423	test $count -gt 0 && echo "These refs were rewritten:"
	424	git show-ref \| grep ^"$orig_namespace"
6f6826c5	425
46eb449c JS	426	unset GIT_DIR GIT_WORK_TREE GIT_INDEX_FILE
	427	test -z "$ORIG_GIT_DIR" \|\| GIT_DIR="$ORIG_GIT_DIR" && export GIT_DIR
	428	test -z "$ORIG_GIT_WORK_TREE" \|\| GIT_WORK_TREE="$ORIG_GIT_WORK_TREE" &&
	429	export GIT_WORK_TREE
	430	test -z "$ORIG_GIT_INDEX_FILE" \|\| GIT_INDEX_FILE="$ORIG_GIT_INDEX_FILE" &&
	431	export GIT_INDEX_FILE
	432	git read-tree -u -m HEAD
	433
6f6826c5	434	exit $ret