[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.

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
}

# 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%%@*}\""
}

# This script can be sourced by the commit filter to get the functions
test "a$SOURCE_FUNCTIONS" = a1 && return
this_script="$(cd "$(dirname "$0")"; pwd)"/$(basename "$0")
export this_script

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

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="$OPTARG"
		;;
	--commit-filter)
		filter_commit='SOURCE_FUNCTIONS=1 . "$this_script";'" $OPTARG"
		;;
	--tag-name-filter)
		filter_tag_name="$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 $ret
Commit	Line	Data
6f6826c5 JS	1	#!/bin/sh
	2	#
	3	# Rewrite revision history
	4	# Copyright (c) Petr Baudis, 2006
	5	# Minimal changes to "port" it to core-git (c) Johannes Schindelin, 2007
	6	#
c401b33c JS	7	# Lets you rewrite the revision history of the current branch, creating
	8	# a new branch. You can specify a number of filters to modify the commits,
	9	# files and trees.
6f6826c5	10
b5669a05 SP	11	warn () {
	12	echo "$*" >&2
	13	}
	14
6f6826c5 JS	15	map()
6f6826c5 JS	16	{
3520e1e8	17	# if it was not rewritten, take the original
c57a3494 JS	18	if test -r "$workdir/../map/$1"
	19	then
	20	cat "$workdir/../map/$1"
	21	else
	22	echo "$1"
	23	fi
6f6826c5 JS	24	}
6f6826c5 JS	25
f95eef15 JS	26	# if you run 'skip_commit "$@"' in a commit filter, it will print
	27	# the (mapped) parents, effectively skipping the commit.
	28
	29	skip_commit()
	30	{
	31	shift;
	32	while [ -n "$1" ];
	33	do
	34	shift;
	35	map "$1";
	36	shift;
	37	done;
	38	}
	39
8c1ce0f4 JS	40	# override die(): this version puts in an extra line break, so that
	41	# the progress is still visible
	42
	43	die()
	44	{
	45	echo >&2
	46	echo "$*" >&2
	47	exit 1
	48	}
	49
6f6826c5 JS	50	# When piped a commit, output a script to set the ident of either
	51	# "author" or "committer
	52
	53	set_ident () {
	54	lid="$(echo "$1" \| tr "A-Z" "a-z")"
	55	uid="$(echo "$1" \| tr "a-z" "A-Z")"
	56	pick_id_script='
	57	/^'$lid' /{
	58	s/'\''/'\''\\'\'\''/g
	59	h
	60	s/^'$lid' \([^<]\) <[^>]> .*$/\1/
	61	s/'\''/'\''\'\'\''/g
	62	s/.*/export GIT_'$uid'_NAME='\''&'\''/p
	63
	64	g
	65	s/^'$lid' [^<]* <\([^>]\)> .$/\1/
	66	s/'\''/'\''\'\'\''/g
	67	s/.*/export GIT_'$uid'_EMAIL='\''&'\''/p
	68
	69	g
	70	s/^'$lid' [^<]* <[^>]> \(.\)$/\1/
	71	s/'\''/'\''\'\'\''/g
	72	s/.*/export GIT_'$uid'_DATE='\''&'\''/p
	73
	74	q
	75	}
	76	'
	77
	78	LANG=C LC_ALL=C sed -ne "$pick_id_script"
	79	# Ensure non-empty id name.
	80	echo "[ -n \"\$GIT_${uid}_NAME\" ] \|\| export GIT_${uid}_NAME=\"\${GIT_${uid}_EMAIL%%@*}\""
	81	}
	82
7e0f1704 JS	83	# This script can be sourced by the commit filter to get the functions
	84	test "a$SOURCE_FUNCTIONS" = a1 && return
	85	this_script="$(cd "$(dirname "$0")"; pwd)"/$(basename "$0")
	86	export this_script
	87
	88	USAGE="[--env-filter <command>] [--tree-filter <command>] \
	89	[--index-filter <command>] [--parent-filter <command>] \
	90	[--msg-filter <command>] [--commit-filter <command>] \
	91	[--tag-name-filter <command>] [--subdirectory-filter <directory>] \
	92	[--original <namespace>] [-d <directory>] [-f \| --force] \
	93	[<rev-list options>...]"
	94
	95	. git-sh-setup
	96
46eb449c JS	97	git diff-files --quiet &&
	98	git diff-index --cached --quiet HEAD \|\|
	99	die "Cannot rewrite branch(es) with a dirty working directory."
	100
6f6826c5	101	tempdir=.git-rewrite
6f6826c5 JS	102	filter_env=
	103	filter_tree=
	104	filter_index=
	105	filter_parent=
	106	filter_msg=cat
5be60078	107	filter_commit='git commit-tree "$@"'
6f6826c5	108	filter_tag_name=
685ef546	109	filter_subdir=
dfd05e38 JS	110	orig_namespace=refs/original/
dfd05e38 JS	111	force=
822f7c73	112	while :
6f6826c5	113	do
822f7c73	114	test $# = 0 && usage
6f6826c5 JS	115	case "$1" in
	116	--)
	117	shift
	118	break
	119	;;
dfd05e38 JS	120	--force\|-f)
	121	shift
	122	force=t
	123	continue
	124	;;
6f6826c5 JS	125	-*)
	126	;;
	127	*)
	128	break;
	129	esac
	130
	131	# all switches take one argument
	132	ARG="$1"
	133	case "$#" in 1) usage ;; esac
	134	shift
	135	OPTARG="$1"
	136	shift
	137
	138	case "$ARG" in
	139	-d)
	140	tempdir="$OPTARG"
	141	;;
6f6826c5 JS	142	--env-filter)
	143	filter_env="$OPTARG"
	144	;;
	145	--tree-filter)
	146	filter_tree="$OPTARG"
	147	;;
	148	--index-filter)
	149	filter_index="$OPTARG"
	150	;;
	151	--parent-filter)
	152	filter_parent="$OPTARG"
	153	;;
	154	--msg-filter)
	155	filter_msg="$OPTARG"
	156	;;
	157	--commit-filter)
7e0f1704	158	filter_commit='SOURCE_FUNCTIONS=1 . "$this_script";'" $OPTARG"
6f6826c5 JS	159	;;
	160	--tag-name-filter)
	161	filter_tag_name="$OPTARG"
	162	;;
685ef546 JS	163	--subdirectory-filter)
	164	filter_subdir="$OPTARG"
	165	;;
dfd05e38	166	--original)
55ced83d	167	orig_namespace=$(expr "$OPTARG/" : '\(.[^/]\)/$')/
dfd05e38	168	;;
6f6826c5 JS	169	*)
	170	usage
	171	;;
	172	esac
	173	done
	174
dfd05e38 JS	175	case "$force" in
	176	t)
	177	rm -rf "$tempdir"
	178	;;
	179	'')
	180	test -d "$tempdir" &&
	181	die "$tempdir already exists, please remove it"
	182	esac
af580e9c	183	mkdir -p "$tempdir/t" &&
dfd05e38	184	tempdir="$(cd "$tempdir"; pwd)" &&
af580e9c JS	185	cd "$tempdir/t" &&
	186	workdir="$(pwd)" \|\|
	187	die ""
6f6826c5	188
dfd05e38 JS	189	# Make sure refs/original is empty
	190	git for-each-ref > "$tempdir"/backup-refs
	191	while read sha1 type name
	192	do
	193	case "$force,$name" in
	194	,$orig_namespace*)
	195	die "Namespace $orig_namespace not empty"
	196	;;
	197	t,$orig_namespace*)
	198	git update-ref -d "$name" $sha1
	199	;;
	200	esac
	201	done < "$tempdir"/backup-refs
	202
46eb449c JS	203	ORIG_GIT_DIR="$GIT_DIR"
	204	ORIG_GIT_WORK_TREE="$GIT_WORK_TREE"
	205	ORIG_GIT_INDEX_FILE="$GIT_INDEX_FILE"
9489d0f1	206	export GIT_DIR GIT_WORK_TREE=.
6f6826c5	207
dfd05e38 JS	208	# These refs should be updated if their heads were rewritten
	209
	210	git rev-parse --revs-only --symbolic "$@" \|
	211	while read ref
	212	do
	213	# normalize ref
	214	case "$ref" in
	215	HEAD)
	216	ref="$(git symbolic-ref "$ref")"
	217	;;
	218	refs/*)
	219	;;
	220	*)
	221	ref="$(git for-each-ref --format='%(refname)' \|
	222	grep /"$ref")"
	223	esac
	224
	225	git check-ref-format "$ref" && echo "$ref"
	226	done > "$tempdir"/heads
	227
	228	test -s "$tempdir"/heads \|\|
	229	die "Which ref do you want to rewrite?"
	230
6f6826c5	231	export GIT_INDEX_FILE="$(pwd)/../index"
af580e9c	232	git read-tree \|\| die "Could not seed the index"
6f6826c5 JS	233
	234	ret=0
	235
af580e9c JS	236	# map old->new commit ids for rewriting parents
af580e9c JS	237	mkdir ../map \|\| die "Could not create map/ directory"
6f6826c5	238
685ef546 JS	239	case "$filter_subdir" in
685ef546 JS	240	"")
5be60078	241	git rev-list --reverse --topo-order --default HEAD \
813b4734	242	--parents "$@"
685ef546 JS	243	;;
685ef546 JS	244	*)
5be60078	245	git rev-list --reverse --topo-order --default HEAD \
cfabd6ee	246	--parents --full-history "$@" -- "$filter_subdir"
af580e9c	247	esac > ../revs \|\| die "Could not get the commits"
9d6f220c	248	commits=$(wc -l <../revs \| tr -d " ")
6f6826c5 JS	249
	250	test $commits -eq 0 && die "Found nothing to rewrite"
	251
dfd05e38 JS	252	# Rewrite the commits
dfd05e38 JS	253
6f6826c5	254	i=0
813b4734	255	while read commit parents; do
c12764b8	256	i=$(($i+1))
5efb48b5	257	printf "\rRewrite $commit ($i/$commits)"
6f6826c5	258
685ef546 JS	259	case "$filter_subdir" in
685ef546 JS	260	"")
5be60078	261	git read-tree -i -m $commit
685ef546 JS	262	;;
685ef546 JS	263	*)
5be60078	264	git read-tree -i -m $commit:"$filter_subdir"
af580e9c	265	esac \|\| die "Could not initialize the index"
6f6826c5 JS	266
6f6826c5 JS	267	export GIT_COMMIT=$commit
af580e9c JS	268	git cat-file commit "$commit" >../commit \|\|
af580e9c JS	269	die "Cannot read commit $commit"
6f6826c5	270
8c1ce0f4 JS	271	eval "$(set_ident AUTHOR <../commit)" \|\|
	272	die "setting author failed for commit $commit"
	273	eval "$(set_ident COMMITTER <../commit)" \|\|
	274	die "setting committer failed for commit $commit"
	275	eval "$filter_env" < /dev/null \|\|
	276	die "env filter failed: $filter_env"
6f6826c5 JS	277
6f6826c5 JS	278	if [ "$filter_tree" ]; then
af580e9c JS	279	git checkout-index -f -u -a \|\|
af580e9c JS	280	die "Could not checkout the index"
6f6826c5 JS	281	# files that $commit removed are now still in the working tree;
6f6826c5 JS	282	# remove them, else they would be added again
5be60078	283	git ls-files -z --others \| xargs -0 rm -f
8c1ce0f4 JS	284	eval "$filter_tree" < /dev/null \|\|
	285	die "tree filter failed: $filter_tree"
	286
5be60078 JH	287	git diff-index -r $commit \| cut -f 2- \| tr '\n' '\0' \| \
	288	xargs -0 git update-index --add --replace --remove
	289	git ls-files -z --others \| \
	290	xargs -0 git update-index --add --replace --remove
6f6826c5 JS	291	fi
6f6826c5 JS	292
8c1ce0f4 JS	293	eval "$filter_index" < /dev/null \|\|
8c1ce0f4 JS	294	die "index filter failed: $filter_index"
6f6826c5 JS	295
6f6826c5 JS	296	parentstr=
813b4734	297	for parent in $parents; do
3520e1e8 JS	298	for reparent in $(map "$parent"); do
	299	parentstr="$parentstr -p $reparent"
	300	done
6f6826c5 JS	301	done
6f6826c5 JS	302	if [ "$filter_parent" ]; then
8c1ce0f4 JS	303	parentstr="$(echo "$parentstr" \| eval "$filter_parent")" \|\|
8c1ce0f4 JS	304	die "parent filter failed: $filter_parent"
6f6826c5 JS	305	fi
	306
	307	sed -e '1,/^$/d' <../commit \| \
8c1ce0f4 JS	308	eval "$filter_msg" > ../message \|\|
	309	die "msg filter failed: $filter_msg"
	310	sh -c "$filter_commit" "git commit-tree" \
	311	$(git write-tree) $parentstr < ../message > ../map/$commit
6f6826c5 JS	312	done <../revs
6f6826c5 JS	313
dfd05e38 JS	314	# In case of a subdirectory filter, it is possible that a specified head
	315	# is not in the set of rewritten commits, because it was pruned by the
	316	# revision walker. Fix it by mapping these heads to the next rewritten
	317	# ancestor(s), i.e. the boundaries in the set of rewritten commits.
	318
	319	# NEEDSWORK: we should sort the unmapped refs topologically first
	320	while read ref
	321	do
	322	sha1=$(git rev-parse "$ref"^0)
	323	test -f "$workdir"/../map/$sha1 && continue
	324	# Assign the boundarie(s) in the set of rewritten commits
	325	# as the replacement commit(s).
	326	# (This would look a bit nicer if --not --stdin worked.)
24d00634	327	for p in $( (cd "$workdir"/../map; ls \| sed "s/^/^/") \|
dfd05e38 JS	328	git rev-list $ref --boundary --stdin \|
	329	sed -n "s/^-//p")
	330	do
	331	map $p >> "$workdir"/../map/$sha1
	332	done
	333	done < "$tempdir"/heads
	334
	335	# Finally update the refs
	336
	337	_x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
	338	_x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
	339	count=0
	340	echo
	341	while read ref
	342	do
	343	# avoid rewriting a ref twice
	344	test -f "$orig_namespace$ref" && continue
	345
	346	sha1=$(git rev-parse "$ref"^0)
	347	rewritten=$(map $sha1)
	348
	349	test $sha1 = "$rewritten" &&
	350	warn "WARNING: Ref '$ref' is unchanged" &&
	351	continue
	352
	353	case "$rewritten" in
	354	'')
	355	echo "Ref '$ref' was deleted"
	356	git update-ref -m "filter-branch: delete" -d "$ref" $sha1 \|\|
	357	die "Could not delete $ref"
98409060	358	;;
dfd05e38 JS	359	$_x40)
	360	echo "Ref '$ref' was rewritten"
	361	git update-ref -m "filter-branch: rewrite" \
	362	"$ref" $rewritten $sha1 \|\|
	363	die "Could not rewrite $ref"
98409060	364	;;
dfd05e38 JS	365	*)
	366	# NEEDSWORK: possibly add -Werror, making this an error
	367	warn "WARNING: '$ref' was rewritten into multiple commits:"
	368	warn "$rewritten"
	369	warn "WARNING: Ref '$ref' points to the first one now."
	370	rewritten=$(echo "$rewritten" \| head -n 1)
	371	git update-ref -m "filter-branch: rewrite to first" \
	372	"$ref" $rewritten $sha1 \|\|
	373	die "Could not rewrite $ref"
	374	;;
	375	esac
	376	git update-ref -m "filter-branch: backup" "$orig_namespace$ref" $sha1
	377	count=$(($count+1))
	378	done < "$tempdir"/heads
	379
	380	# TODO: This should possibly go, with the semantics that all positive given
	381	# refs are updated, and their original heads stored in refs/original/
	382	# Filter tags
6f6826c5 JS	383
6f6826c5 JS	384	if [ "$filter_tag_name" ]; then
5be60078	385	git for-each-ref --format='%(objectname) %(objecttype) %(refname)' refs/tags \|
6f6826c5 JS	386	while read sha1 type ref; do
	387	ref="${ref#refs/tags/}"
	388	# XXX: Rewrite tagged trees as well?
	389	if [ "$type" != "commit" -a "$type" != "tag" ]; then
	390	continue;
	391	fi
	392
	393	if [ "$type" = "tag" ]; then
	394	# Dereference to a commit
	395	sha1t="$sha1"
5be60078	396	sha1="$(git rev-parse "$sha1"^{commit} 2>/dev/null)" \|\| continue
6f6826c5 JS	397	fi
	398
	399	[ -f "../map/$sha1" ] \|\| continue
	400	new_sha1="$(cat "../map/$sha1")"
	401	export GIT_COMMIT="$sha1"
8c1ce0f4 JS	402	new_ref="$(echo "$ref" \| eval "$filter_tag_name")" \|\|
8c1ce0f4 JS	403	die "tag name filter failed: $filter_tag_name"
6f6826c5 JS	404
	405	echo "$ref -> $new_ref ($sha1 -> $new_sha1)"
	406
	407	if [ "$type" = "tag" ]; then
	408	# Warn that we are not rewriting the tag object itself.
	409	warn "unreferencing tag object $sha1t"
	410	fi
	411
af580e9c JS	412	git update-ref "refs/tags/$new_ref" "$new_sha1" \|\|
af580e9c JS	413	die "Could not write tag $new_ref"
6f6826c5 JS	414	done
	415	fi
	416
	417	cd ../..
	418	rm -rf "$tempdir"
dfd05e38 JS	419	echo
	420	test $count -gt 0 && echo "These refs were rewritten:"
	421	git show-ref \| grep ^"$orig_namespace"
6f6826c5	422
46eb449c JS	423	unset GIT_DIR GIT_WORK_TREE GIT_INDEX_FILE
	424	test -z "$ORIG_GIT_DIR" \|\| GIT_DIR="$ORIG_GIT_DIR" && export GIT_DIR
	425	test -z "$ORIG_GIT_WORK_TREE" \|\| GIT_WORK_TREE="$ORIG_GIT_WORK_TREE" &&
	426	export GIT_WORK_TREE
	427	test -z "$ORIG_GIT_INDEX_FILE" \|\| GIT_INDEX_FILE="$ORIG_GIT_INDEX_FILE" &&
	428	export GIT_INDEX_FILE
	429	git read-tree -u -m HEAD
	430
6f6826c5	431	exit $ret