[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.

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>...]"

. git-sh-setup

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
}

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

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

# 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%%@*}\""
}

tempdir=.git-rewrite
filter_env=
filter_tree=
filter_index=
filter_parent=
filter_msg=cat
filter_commit='git commit-tree "$@"'
filter_tag_name=
filter_subdir=
orig_namespace=refs/original/
force=
while case "$#" in 0) usage;; esac
do
	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="$OPTARG"
		;;
	--commit-filter)
		filter_commit="$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

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"

exit $ret
Commit	Line	Data
6f6826c5 JS	1	#!/bin/sh
	2	#
	3	# Rewrite revision history
	4	# Copyright (c) Petr Baudis, 2006
	5	# Minimal changes to "port" it to core-git (c) Johannes Schindelin, 2007
	6	#
c401b33c JS	7	# Lets you rewrite the revision history of the current branch, creating
	8	# a new branch. You can specify a number of filters to modify the commits,
	9	# files and trees.
6f6826c5	10
26a65dea GB	11	USAGE="[--env-filter <command>] [--tree-filter <command>] \
	12	[--index-filter <command>] [--parent-filter <command>] \
	13	[--msg-filter <command>] [--commit-filter <command>] \
	14	[--tag-name-filter <command>] [--subdirectory-filter <directory>] \
	15	[--original <namespace>] [-d <directory>] [-f \| --force] \
	16	[<rev-list options>...]"
	17
6f6826c5 JS	18	. git-sh-setup
6f6826c5 JS	19
b5669a05 SP	20	warn () {
	21	echo "$*" >&2
	22	}
	23
6f6826c5 JS	24	map()
6f6826c5 JS	25	{
3520e1e8	26	# if it was not rewritten, take the original
c57a3494 JS	27	if test -r "$workdir/../map/$1"
	28	then
	29	cat "$workdir/../map/$1"
	30	else
	31	echo "$1"
	32	fi
6f6826c5 JS	33	}
6f6826c5 JS	34
8c1ce0f4 JS	35	# override die(): this version puts in an extra line break, so that
	36	# the progress is still visible
	37
	38	die()
	39	{
	40	echo >&2
	41	echo "$*" >&2
	42	exit 1
	43	}
	44
6f6826c5 JS	45	# When piped a commit, output a script to set the ident of either
	46	# "author" or "committer
	47
	48	set_ident () {
	49	lid="$(echo "$1" \| tr "A-Z" "a-z")"
	50	uid="$(echo "$1" \| tr "a-z" "A-Z")"
	51	pick_id_script='
	52	/^'$lid' /{
	53	s/'\''/'\''\\'\'\''/g
	54	h
	55	s/^'$lid' \([^<]\) <[^>]> .*$/\1/
	56	s/'\''/'\''\'\'\''/g
	57	s/.*/export GIT_'$uid'_NAME='\''&'\''/p
	58
	59	g
	60	s/^'$lid' [^<]* <\([^>]\)> .$/\1/
	61	s/'\''/'\''\'\'\''/g
	62	s/.*/export GIT_'$uid'_EMAIL='\''&'\''/p
	63
	64	g
	65	s/^'$lid' [^<]* <[^>]> \(.\)$/\1/
	66	s/'\''/'\''\'\'\''/g
	67	s/.*/export GIT_'$uid'_DATE='\''&'\''/p
	68
	69	q
	70	}
	71	'
	72
	73	LANG=C LC_ALL=C sed -ne "$pick_id_script"
	74	# Ensure non-empty id name.
	75	echo "[ -n \"\$GIT_${uid}_NAME\" ] \|\| export GIT_${uid}_NAME=\"\${GIT_${uid}_EMAIL%%@*}\""
	76	}
	77
6f6826c5	78	tempdir=.git-rewrite
6f6826c5 JS	79	filter_env=
	80	filter_tree=
	81	filter_index=
	82	filter_parent=
	83	filter_msg=cat
5be60078	84	filter_commit='git commit-tree "$@"'
6f6826c5	85	filter_tag_name=
685ef546	86	filter_subdir=
dfd05e38 JS	87	orig_namespace=refs/original/
dfd05e38 JS	88	force=
6f6826c5 JS	89	while case "$#" in 0) usage;; esac
	90	do
	91	case "$1" in
	92	--)
	93	shift
	94	break
	95	;;
dfd05e38 JS	96	--force\|-f)
	97	shift
	98	force=t
	99	continue
	100	;;
6f6826c5 JS	101	-*)
	102	;;
	103	*)
	104	break;
	105	esac
	106
	107	# all switches take one argument
	108	ARG="$1"
	109	case "$#" in 1) usage ;; esac
	110	shift
	111	OPTARG="$1"
	112	shift
	113
	114	case "$ARG" in
	115	-d)
	116	tempdir="$OPTARG"
	117	;;
6f6826c5 JS	118	--env-filter)
	119	filter_env="$OPTARG"
	120	;;
	121	--tree-filter)
	122	filter_tree="$OPTARG"
	123	;;
	124	--index-filter)
	125	filter_index="$OPTARG"
	126	;;
	127	--parent-filter)
	128	filter_parent="$OPTARG"
	129	;;
	130	--msg-filter)
	131	filter_msg="$OPTARG"
	132	;;
	133	--commit-filter)
	134	filter_commit="$OPTARG"
	135	;;
	136	--tag-name-filter)
	137	filter_tag_name="$OPTARG"
	138	;;
685ef546 JS	139	--subdirectory-filter)
	140	filter_subdir="$OPTARG"
	141	;;
dfd05e38	142	--original)
55ced83d	143	orig_namespace=$(expr "$OPTARG/" : '\(.[^/]\)/$')/
dfd05e38	144	;;
6f6826c5 JS	145	*)
	146	usage
	147	;;
	148	esac
	149	done
	150
dfd05e38 JS	151	case "$force" in
	152	t)
	153	rm -rf "$tempdir"
	154	;;
	155	'')
	156	test -d "$tempdir" &&
	157	die "$tempdir already exists, please remove it"
	158	esac
af580e9c	159	mkdir -p "$tempdir/t" &&
dfd05e38	160	tempdir="$(cd "$tempdir"; pwd)" &&
af580e9c JS	161	cd "$tempdir/t" &&
	162	workdir="$(pwd)" \|\|
	163	die ""
6f6826c5	164
dfd05e38 JS	165	# Make sure refs/original is empty
	166	git for-each-ref > "$tempdir"/backup-refs
	167	while read sha1 type name
	168	do
	169	case "$force,$name" in
	170	,$orig_namespace*)
	171	die "Namespace $orig_namespace not empty"
	172	;;
	173	t,$orig_namespace*)
	174	git update-ref -d "$name" $sha1
	175	;;
	176	esac
	177	done < "$tempdir"/backup-refs
	178
9489d0f1	179	export GIT_DIR GIT_WORK_TREE=.
6f6826c5	180
dfd05e38 JS	181	# These refs should be updated if their heads were rewritten
	182
	183	git rev-parse --revs-only --symbolic "$@" \|
	184	while read ref
	185	do
	186	# normalize ref
	187	case "$ref" in
	188	HEAD)
	189	ref="$(git symbolic-ref "$ref")"
	190	;;
	191	refs/*)
	192	;;
	193	*)
	194	ref="$(git for-each-ref --format='%(refname)' \|
	195	grep /"$ref")"
	196	esac
	197
	198	git check-ref-format "$ref" && echo "$ref"
	199	done > "$tempdir"/heads
	200
	201	test -s "$tempdir"/heads \|\|
	202	die "Which ref do you want to rewrite?"
	203
6f6826c5	204	export GIT_INDEX_FILE="$(pwd)/../index"
af580e9c	205	git read-tree \|\| die "Could not seed the index"
6f6826c5 JS	206
	207	ret=0
	208
af580e9c JS	209	# map old->new commit ids for rewriting parents
af580e9c JS	210	mkdir ../map \|\| die "Could not create map/ directory"
6f6826c5	211
685ef546 JS	212	case "$filter_subdir" in
685ef546 JS	213	"")
5be60078	214	git rev-list --reverse --topo-order --default HEAD \
813b4734	215	--parents "$@"
685ef546 JS	216	;;
685ef546 JS	217	*)
5be60078	218	git rev-list --reverse --topo-order --default HEAD \
cfabd6ee	219	--parents --full-history "$@" -- "$filter_subdir"
af580e9c	220	esac > ../revs \|\| die "Could not get the commits"
9d6f220c	221	commits=$(wc -l <../revs \| tr -d " ")
6f6826c5 JS	222
	223	test $commits -eq 0 && die "Found nothing to rewrite"
	224
dfd05e38 JS	225	# Rewrite the commits
dfd05e38 JS	226
6f6826c5	227	i=0
813b4734	228	while read commit parents; do
c12764b8	229	i=$(($i+1))
5efb48b5	230	printf "\rRewrite $commit ($i/$commits)"
6f6826c5	231
685ef546 JS	232	case "$filter_subdir" in
685ef546 JS	233	"")
5be60078	234	git read-tree -i -m $commit
685ef546 JS	235	;;
685ef546 JS	236	*)
5be60078	237	git read-tree -i -m $commit:"$filter_subdir"
af580e9c	238	esac \|\| die "Could not initialize the index"
6f6826c5 JS	239
6f6826c5 JS	240	export GIT_COMMIT=$commit
af580e9c JS	241	git cat-file commit "$commit" >../commit \|\|
af580e9c JS	242	die "Cannot read commit $commit"
6f6826c5	243
8c1ce0f4 JS	244	eval "$(set_ident AUTHOR <../commit)" \|\|
	245	die "setting author failed for commit $commit"
	246	eval "$(set_ident COMMITTER <../commit)" \|\|
	247	die "setting committer failed for commit $commit"
	248	eval "$filter_env" < /dev/null \|\|
	249	die "env filter failed: $filter_env"
6f6826c5 JS	250
6f6826c5 JS	251	if [ "$filter_tree" ]; then
af580e9c JS	252	git checkout-index -f -u -a \|\|
af580e9c JS	253	die "Could not checkout the index"
6f6826c5 JS	254	# files that $commit removed are now still in the working tree;
6f6826c5 JS	255	# remove them, else they would be added again
5be60078	256	git ls-files -z --others \| xargs -0 rm -f
8c1ce0f4 JS	257	eval "$filter_tree" < /dev/null \|\|
	258	die "tree filter failed: $filter_tree"
	259
5be60078 JH	260	git diff-index -r $commit \| cut -f 2- \| tr '\n' '\0' \| \
	261	xargs -0 git update-index --add --replace --remove
	262	git ls-files -z --others \| \
	263	xargs -0 git update-index --add --replace --remove
6f6826c5 JS	264	fi
6f6826c5 JS	265
8c1ce0f4 JS	266	eval "$filter_index" < /dev/null \|\|
8c1ce0f4 JS	267	die "index filter failed: $filter_index"
6f6826c5 JS	268
6f6826c5 JS	269	parentstr=
813b4734	270	for parent in $parents; do
3520e1e8 JS	271	for reparent in $(map "$parent"); do
	272	parentstr="$parentstr -p $reparent"
	273	done
6f6826c5 JS	274	done
6f6826c5 JS	275	if [ "$filter_parent" ]; then
8c1ce0f4 JS	276	parentstr="$(echo "$parentstr" \| eval "$filter_parent")" \|\|
8c1ce0f4 JS	277	die "parent filter failed: $filter_parent"
6f6826c5 JS	278	fi
	279
	280	sed -e '1,/^$/d' <../commit \| \
8c1ce0f4 JS	281	eval "$filter_msg" > ../message \|\|
	282	die "msg filter failed: $filter_msg"
	283	sh -c "$filter_commit" "git commit-tree" \
	284	$(git write-tree) $parentstr < ../message > ../map/$commit
6f6826c5 JS	285	done <../revs
6f6826c5 JS	286
dfd05e38 JS	287	# In case of a subdirectory filter, it is possible that a specified head
	288	# is not in the set of rewritten commits, because it was pruned by the
	289	# revision walker. Fix it by mapping these heads to the next rewritten
	290	# ancestor(s), i.e. the boundaries in the set of rewritten commits.
	291
	292	# NEEDSWORK: we should sort the unmapped refs topologically first
	293	while read ref
	294	do
	295	sha1=$(git rev-parse "$ref"^0)
	296	test -f "$workdir"/../map/$sha1 && continue
	297	# Assign the boundarie(s) in the set of rewritten commits
	298	# as the replacement commit(s).
	299	# (This would look a bit nicer if --not --stdin worked.)
24d00634	300	for p in $( (cd "$workdir"/../map; ls \| sed "s/^/^/") \|
dfd05e38 JS	301	git rev-list $ref --boundary --stdin \|
	302	sed -n "s/^-//p")
	303	do
	304	map $p >> "$workdir"/../map/$sha1
	305	done
	306	done < "$tempdir"/heads
	307
	308	# Finally update the refs
	309
	310	_x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
	311	_x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
	312	count=0
	313	echo
	314	while read ref
	315	do
	316	# avoid rewriting a ref twice
	317	test -f "$orig_namespace$ref" && continue
	318
	319	sha1=$(git rev-parse "$ref"^0)
	320	rewritten=$(map $sha1)
	321
	322	test $sha1 = "$rewritten" &&
	323	warn "WARNING: Ref '$ref' is unchanged" &&
	324	continue
	325
	326	case "$rewritten" in
	327	'')
	328	echo "Ref '$ref' was deleted"
	329	git update-ref -m "filter-branch: delete" -d "$ref" $sha1 \|\|
	330	die "Could not delete $ref"
98409060	331	;;
dfd05e38 JS	332	$_x40)
	333	echo "Ref '$ref' was rewritten"
	334	git update-ref -m "filter-branch: rewrite" \
	335	"$ref" $rewritten $sha1 \|\|
	336	die "Could not rewrite $ref"
98409060	337	;;
dfd05e38 JS	338	*)
	339	# NEEDSWORK: possibly add -Werror, making this an error
	340	warn "WARNING: '$ref' was rewritten into multiple commits:"
	341	warn "$rewritten"
	342	warn "WARNING: Ref '$ref' points to the first one now."
	343	rewritten=$(echo "$rewritten" \| head -n 1)
	344	git update-ref -m "filter-branch: rewrite to first" \
	345	"$ref" $rewritten $sha1 \|\|
	346	die "Could not rewrite $ref"
	347	;;
	348	esac
	349	git update-ref -m "filter-branch: backup" "$orig_namespace$ref" $sha1
	350	count=$(($count+1))
	351	done < "$tempdir"/heads
	352
	353	# TODO: This should possibly go, with the semantics that all positive given
	354	# refs are updated, and their original heads stored in refs/original/
	355	# Filter tags
6f6826c5 JS	356
6f6826c5 JS	357	if [ "$filter_tag_name" ]; then
5be60078	358	git for-each-ref --format='%(objectname) %(objecttype) %(refname)' refs/tags \|
6f6826c5 JS	359	while read sha1 type ref; do
	360	ref="${ref#refs/tags/}"
	361	# XXX: Rewrite tagged trees as well?
	362	if [ "$type" != "commit" -a "$type" != "tag" ]; then
	363	continue;
	364	fi
	365
	366	if [ "$type" = "tag" ]; then
	367	# Dereference to a commit
	368	sha1t="$sha1"
5be60078	369	sha1="$(git rev-parse "$sha1"^{commit} 2>/dev/null)" \|\| continue
6f6826c5 JS	370	fi
	371
	372	[ -f "../map/$sha1" ] \|\| continue
	373	new_sha1="$(cat "../map/$sha1")"
	374	export GIT_COMMIT="$sha1"
8c1ce0f4 JS	375	new_ref="$(echo "$ref" \| eval "$filter_tag_name")" \|\|
8c1ce0f4 JS	376	die "tag name filter failed: $filter_tag_name"
6f6826c5 JS	377
	378	echo "$ref -> $new_ref ($sha1 -> $new_sha1)"
	379
	380	if [ "$type" = "tag" ]; then
	381	# Warn that we are not rewriting the tag object itself.
	382	warn "unreferencing tag object $sha1t"
	383	fi
	384
af580e9c JS	385	git update-ref "refs/tags/$new_ref" "$new_sha1" \|\|
af580e9c JS	386	die "Could not write tag $new_ref"
6f6826c5 JS	387	done
	388	fi
	389
	390	cd ../..
	391	rm -rf "$tempdir"
dfd05e38 JS	392	echo
	393	test $count -gt 0 && echo "These refs were rewritten:"
	394	git show-ref \| grep ^"$orig_namespace"
6f6826c5 JS	395
6f6826c5 JS	396	exit $ret