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

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

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

			q
		}
	'

	LANG=C LC_ALL=C sed -ne "$pick_id_script"
	# Ensure non-empty id name.
	echo "case \"\$GIT_${uid}_NAME\" in \"\") GIT_${uid}_NAME=\"\${GIT_${uid}_EMAIL%%@*}\" && export GIT_${uid}_NAME;; esac"
}

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
	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 ""

# Remove tempdir on exit
trap 'cd ../..; rm -rf "$tempdir"' 0

# 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"
GIT_WORK_TREE=.
export GIT_DIR GIT_WORK_TREE

# The refs should be updated if their heads were rewritten
git rev-parse --no-flags --revs-only --symbolic-full-name --default HEAD "$@" |
sed -e '/^^/d' >"$tempdir"/heads

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

GIT_INDEX_FILE="$(pwd)/../index"
export GIT_INDEX_FILE
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"

	GIT_COMMIT=$commit
	export GIT_COMMIT
	git cat-file commit "$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 --name-only $commit
			git ls-files --others
		) |
		git update-index --add --replace --remove --stdin
	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"
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" $sha1
done < "$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/$sha1")"
		GIT_COMMIT="$sha1"
		export GIT_COMMIT
		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"

trap - 0

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' \([^<]\) <[^>]> .*$/\1/
	68	s/'\''/'\''\'\'\''/g
3addc94a	69	s/.*/GIT_'$uid'_NAME='\''&'\''; export GIT_'$uid'_NAME/p
6f6826c5 JS	70
	71	g
	72	s/^'$lid' [^<]* <\([^>]\)> .$/\1/
	73	s/'\''/'\''\'\'\''/g
3addc94a	74	s/.*/GIT_'$uid'_EMAIL='\''&'\''; export GIT_'$uid'_EMAIL/p
6f6826c5 JS	75
	76	g
	77	s/^'$lid' [^<]* <[^>]> \(.\)$/\1/
	78	s/'\''/'\''\'\'\''/g
3addc94a	79	s/.*/GIT_'$uid'_DATE='\''&'\''; export GIT_'$uid'_DATE/p
6f6826c5 JS	80
	81	q
	82	}
	83	'
	84
	85	LANG=C LC_ALL=C sed -ne "$pick_id_script"
	86	# Ensure non-empty id name.
3addc94a	87	echo "case \"\$GIT_${uid}_NAME\" in \"\") GIT_${uid}_NAME=\"\${GIT_${uid}_EMAIL%%@*}\" && export GIT_${uid}_NAME;; esac"
6f6826c5 JS	88	}
6f6826c5 JS	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] \
bb8eebb9	95	[<rev-list options>...]"
7e0f1704	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 JS	116	do
	117	case "$1" in
	118	--)
	119	shift
	120	break
	121	;;
dfd05e38 JS	122	--force\|-f)
	123	shift
	124	force=t
	125	continue
	126	;;
6f6826c5 JS	127	-*)
	128	;;
	129	*)
	130	break;
	131	esac
	132
	133	# all switches take one argument
	134	ARG="$1"
	135	case "$#" in 1) usage ;; esac
	136	shift
	137	OPTARG="$1"
	138	shift
	139
	140	case "$ARG" in
	141	-d)
	142	tempdir="$OPTARG"
	143	;;
6f6826c5 JS	144	--env-filter)
	145	filter_env="$OPTARG"
	146	;;
	147	--tree-filter)
	148	filter_tree="$OPTARG"
	149	;;
	150	--index-filter)
	151	filter_index="$OPTARG"
	152	;;
	153	--parent-filter)
	154	filter_parent="$OPTARG"
	155	;;
	156	--msg-filter)
	157	filter_msg="$OPTARG"
	158	;;
	159	--commit-filter)
16ed34ad	160	filter_commit="$functions; $OPTARG"
6f6826c5 JS	161	;;
	162	--tag-name-filter)
	163	filter_tag_name="$OPTARG"
	164	;;
685ef546 JS	165	--subdirectory-filter)
	166	filter_subdir="$OPTARG"
	167	;;
dfd05e38	168	--original)
55ced83d	169	orig_namespace=$(expr "$OPTARG/" : '\(.[^/]\)/$')/
dfd05e38	170	;;
6f6826c5 JS	171	*)
	172	usage
	173	;;
	174	esac
	175	done
	176
dfd05e38 JS	177	case "$force" in
	178	t)
	179	rm -rf "$tempdir"
	180	;;
	181	'')
	182	test -d "$tempdir" &&
	183	die "$tempdir already exists, please remove it"
	184	esac
af580e9c	185	mkdir -p "$tempdir/t" &&
dfd05e38	186	tempdir="$(cd "$tempdir"; pwd)" &&
af580e9c JS	187	cd "$tempdir/t" &&
	188	workdir="$(pwd)" \|\|
	189	die ""
6f6826c5	190
def16e71 BC	191	# Remove tempdir on exit
	192	trap 'cd ../..; rm -rf "$tempdir"' 0
	193
dfd05e38 JS	194	# Make sure refs/original is empty
	195	git for-each-ref > "$tempdir"/backup-refs
	196	while read sha1 type name
	197	do
	198	case "$force,$name" in
	199	,$orig_namespace*)
	200	die "Namespace $orig_namespace not empty"
	201	;;
	202	t,$orig_namespace*)
	203	git update-ref -d "$name" $sha1
	204	;;
	205	esac
	206	done < "$tempdir"/backup-refs
	207
46eb449c JS	208	ORIG_GIT_DIR="$GIT_DIR"
	209	ORIG_GIT_WORK_TREE="$GIT_WORK_TREE"
	210	ORIG_GIT_INDEX_FILE="$GIT_INDEX_FILE"
3addc94a JS	211	GIT_WORK_TREE=.
3addc94a JS	212	export GIT_DIR GIT_WORK_TREE
6f6826c5	213
418fa3a5	214	# The refs should be updated if their heads were rewritten
0f047f3b	215	git rev-parse --no-flags --revs-only --symbolic-full-name --default HEAD "$@" \|
418fa3a5	216	sed -e '/^^/d' >"$tempdir"/heads
dfd05e38 JS	217
	218	test -s "$tempdir"/heads \|\|
	219	die "Which ref do you want to rewrite?"
	220
3addc94a JS	221	GIT_INDEX_FILE="$(pwd)/../index"
3addc94a JS	222	export GIT_INDEX_FILE
af580e9c	223	git read-tree \|\| die "Could not seed the index"
6f6826c5 JS	224
	225	ret=0
	226
af580e9c JS	227	# map old->new commit ids for rewriting parents
af580e9c JS	228	mkdir ../map \|\| die "Could not create map/ directory"
6f6826c5	229
685ef546 JS	230	case "$filter_subdir" in
685ef546 JS	231	"")
5be60078	232	git rev-list --reverse --topo-order --default HEAD \
813b4734	233	--parents "$@"
685ef546 JS	234	;;
685ef546 JS	235	*)
5be60078	236	git rev-list --reverse --topo-order --default HEAD \
cfabd6ee	237	--parents --full-history "$@" -- "$filter_subdir"
af580e9c	238	esac > ../revs \|\| die "Could not get the commits"
9d6f220c	239	commits=$(wc -l <../revs \| tr -d " ")
6f6826c5 JS	240
	241	test $commits -eq 0 && die "Found nothing to rewrite"
	242
dfd05e38 JS	243	# Rewrite the commits
dfd05e38 JS	244
6f6826c5	245	i=0
813b4734	246	while read commit parents; do
c12764b8	247	i=$(($i+1))
5efb48b5	248	printf "\rRewrite $commit ($i/$commits)"
6f6826c5	249
685ef546 JS	250	case "$filter_subdir" in
685ef546 JS	251	"")
5be60078	252	git read-tree -i -m $commit
685ef546 JS	253	;;
685ef546 JS	254	*)
5be60078	255	git read-tree -i -m $commit:"$filter_subdir"
af580e9c	256	esac \|\| die "Could not initialize the index"
6f6826c5	257
3addc94a JS	258	GIT_COMMIT=$commit
3addc94a JS	259	export GIT_COMMIT
af580e9c JS	260	git cat-file commit "$commit" >../commit \|\|
af580e9c JS	261	die "Cannot read commit $commit"
6f6826c5	262
8c1ce0f4 JS	263	eval "$(set_ident AUTHOR <../commit)" \|\|
	264	die "setting author failed for commit $commit"
	265	eval "$(set_ident COMMITTER <../commit)" \|\|
	266	die "setting committer failed for commit $commit"
	267	eval "$filter_env" < /dev/null \|\|
	268	die "env filter failed: $filter_env"
6f6826c5 JS	269
6f6826c5 JS	270	if [ "$filter_tree" ]; then
af580e9c JS	271	git checkout-index -f -u -a \|\|
af580e9c JS	272	die "Could not checkout the index"
6f6826c5 JS	273	# files that $commit removed are now still in the working tree;
6f6826c5 JS	274	# remove them, else they would be added again
5be60078	275	git ls-files -z --others \| xargs -0 rm -f
8c1ce0f4 JS	276	eval "$filter_tree" < /dev/null \|\|
	277	die "tree filter failed: $filter_tree"
	278
1fe32cb9 JH	279	(
	280	git diff-index -r --name-only $commit
	281	git ls-files --others
	282	) \|
	283	git update-index --add --replace --remove --stdin
6f6826c5 JS	284	fi
6f6826c5 JS	285
8c1ce0f4 JS	286	eval "$filter_index" < /dev/null \|\|
8c1ce0f4 JS	287	die "index filter failed: $filter_index"
6f6826c5 JS	288
6f6826c5 JS	289	parentstr=
813b4734	290	for parent in $parents; do
3520e1e8 JS	291	for reparent in $(map "$parent"); do
	292	parentstr="$parentstr -p $reparent"
	293	done
6f6826c5 JS	294	done
6f6826c5 JS	295	if [ "$filter_parent" ]; then
8c1ce0f4 JS	296	parentstr="$(echo "$parentstr" \| eval "$filter_parent")" \|\|
8c1ce0f4 JS	297	die "parent filter failed: $filter_parent"
6f6826c5 JS	298	fi
	299
	300	sed -e '1,/^$/d' <../commit \| \
8c1ce0f4 JS	301	eval "$filter_msg" > ../message \|\|
	302	die "msg filter failed: $filter_msg"
	303	sh -c "$filter_commit" "git commit-tree" \
	304	$(git write-tree) $parentstr < ../message > ../map/$commit
6f6826c5 JS	305	done <../revs
6f6826c5 JS	306
dfd05e38 JS	307	# In case of a subdirectory filter, it is possible that a specified head
	308	# is not in the set of rewritten commits, because it was pruned by the
	309	# revision walker. Fix it by mapping these heads to the next rewritten
	310	# ancestor(s), i.e. the boundaries in the set of rewritten commits.
	311
	312	# NEEDSWORK: we should sort the unmapped refs topologically first
	313	while read ref
	314	do
	315	sha1=$(git rev-parse "$ref"^0)
	316	test -f "$workdir"/../map/$sha1 && continue
	317	# Assign the boundarie(s) in the set of rewritten commits
	318	# as the replacement commit(s).
	319	# (This would look a bit nicer if --not --stdin worked.)
24d00634	320	for p in $( (cd "$workdir"/../map; ls \| sed "s/^/^/") \|
dfd05e38 JS	321	git rev-list $ref --boundary --stdin \|
	322	sed -n "s/^-//p")
	323	do
	324	map $p >> "$workdir"/../map/$sha1
	325	done
	326	done < "$tempdir"/heads
	327
	328	# Finally update the refs
	329
	330	_x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
	331	_x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
dfd05e38 JS	332	echo
	333	while read ref
	334	do
	335	# avoid rewriting a ref twice
	336	test -f "$orig_namespace$ref" && continue
	337
	338	sha1=$(git rev-parse "$ref"^0)
	339	rewritten=$(map $sha1)
	340
	341	test $sha1 = "$rewritten" &&
	342	warn "WARNING: Ref '$ref' is unchanged" &&
	343	continue
	344
	345	case "$rewritten" in
	346	'')
	347	echo "Ref '$ref' was deleted"
	348	git update-ref -m "filter-branch: delete" -d "$ref" $sha1 \|\|
	349	die "Could not delete $ref"
98409060	350	;;
dfd05e38 JS	351	$_x40)
	352	echo "Ref '$ref' was rewritten"
	353	git update-ref -m "filter-branch: rewrite" \
	354	"$ref" $rewritten $sha1 \|\|
	355	die "Could not rewrite $ref"
98409060	356	;;
dfd05e38 JS	357	*)
	358	# NEEDSWORK: possibly add -Werror, making this an error
	359	warn "WARNING: '$ref' was rewritten into multiple commits:"
	360	warn "$rewritten"
	361	warn "WARNING: Ref '$ref' points to the first one now."
	362	rewritten=$(echo "$rewritten" \| head -n 1)
	363	git update-ref -m "filter-branch: rewrite to first" \
	364	"$ref" $rewritten $sha1 \|\|
	365	die "Could not rewrite $ref"
	366	;;
	367	esac
	368	git update-ref -m "filter-branch: backup" "$orig_namespace$ref" $sha1
dfd05e38 JS	369	done < "$tempdir"/heads
	370
	371	# TODO: This should possibly go, with the semantics that all positive given
	372	# refs are updated, and their original heads stored in refs/original/
	373	# Filter tags
6f6826c5 JS	374
6f6826c5 JS	375	if [ "$filter_tag_name" ]; then
5be60078	376	git for-each-ref --format='%(objectname) %(objecttype) %(refname)' refs/tags \|
6f6826c5 JS	377	while read sha1 type ref; do
	378	ref="${ref#refs/tags/}"
	379	# XXX: Rewrite tagged trees as well?
	380	if [ "$type" != "commit" -a "$type" != "tag" ]; then
	381	continue;
	382	fi
	383
	384	if [ "$type" = "tag" ]; then
	385	# Dereference to a commit
	386	sha1t="$sha1"
5be60078	387	sha1="$(git rev-parse "$sha1"^{commit} 2>/dev/null)" \|\| continue
6f6826c5 JS	388	fi
	389
	390	[ -f "../map/$sha1" ] \|\| continue
	391	new_sha1="$(cat "../map/$sha1")"
3addc94a JS	392	GIT_COMMIT="$sha1"
3addc94a JS	393	export GIT_COMMIT
8c1ce0f4 JS	394	new_ref="$(echo "$ref" \| eval "$filter_tag_name")" \|\|
8c1ce0f4 JS	395	die "tag name filter failed: $filter_tag_name"
6f6826c5 JS	396
	397	echo "$ref -> $new_ref ($sha1 -> $new_sha1)"
	398
	399	if [ "$type" = "tag" ]; then
	400	# Warn that we are not rewriting the tag object itself.
	401	warn "unreferencing tag object $sha1t"
	402	fi
	403
af580e9c JS	404	git update-ref "refs/tags/$new_ref" "$new_sha1" \|\|
af580e9c JS	405	die "Could not write tag $new_ref"
6f6826c5 JS	406	done
	407	fi
	408
	409	cd ../..
	410	rm -rf "$tempdir"
6f6826c5	411
def16e71 BC	412	trap - 0
def16e71 BC	413
46eb449c JS	414	unset GIT_DIR GIT_WORK_TREE GIT_INDEX_FILE
	415	test -z "$ORIG_GIT_DIR" \|\| GIT_DIR="$ORIG_GIT_DIR" && export GIT_DIR
	416	test -z "$ORIG_GIT_WORK_TREE" \|\| GIT_WORK_TREE="$ORIG_GIT_WORK_TREE" &&
	417	export GIT_WORK_TREE
	418	test -z "$ORIG_GIT_INDEX_FILE" \|\| GIT_INDEX_FILE="$ORIG_GIT_INDEX_FILE" &&
	419	export GIT_INDEX_FILE
	420	git read-tree -u -m HEAD
	421
6f6826c5	422	exit $ret