FM / subtree

/snap/gh/640/usr/share/doc/git/contrib/subtree/

/snap/gh/640/usr/share/doc/git/contrib/subtree

Name	Size	Mode	Actions
t/	-	0755	rm
COPYING	-	0	edit dl rm
git-subtree	25019	0644	edit dl rm
git-subtree.sh	25019	0644	edit dl rm
git-subtree.txt	13687	0644	edit dl rm
INSTALL	566	0644	edit dl rm
Makefile	2533	0644	edit dl rm
README	211	0644	edit dl rm
todo	1683	0644	edit dl rm

Edit: /snap/gh/640/usr/share/doc/git/contrib/subtree/git-subtree.sh (25019B)

#!/bin/sh
#
# git-subtree.sh: split/join git repositories in subdirectories of this one
#
# Copyright (C) 2009 Avery Pennarun <apenwarr@gmail.com>
#

if test -z "$GIT_EXEC_PATH" || ! test -f "$GIT_EXEC_PATH/git-sh-setup" || {
	test "${PATH#"${GIT_EXEC_PATH}:"}" = "$PATH" &&
	test ! "$GIT_EXEC_PATH" -ef "${PATH%%:*}" 2>/dev/null
}
then
	basename=${0##*[/\\]}
	echo >&2 'It looks like either your git installation or your'
	echo >&2 'git-subtree installation is broken.'
	echo >&2
	echo >&2 "Tips:"
	echo >&2 " - If \`git --exec-path\` does not print the correct path to"
	echo >&2 "   your git install directory, then set the GIT_EXEC_PATH"
	echo >&2 "   environment variable to the correct directory."
	echo >&2 " - Make sure that your \`$basename\` file is either in your"
	echo >&2 "   PATH or in your git exec path (\`$(git --exec-path)\`)."
	echo >&2 " - You should run git-subtree as \`git ${basename#git-}\`,"
	echo >&2 "   not as \`$basename\`." >&2
	exit 126
fi

OPTS_SPEC="\
git subtree add   --prefix=<prefix> <commit>
git subtree add   --prefix=<prefix> <repository> <ref>
git subtree merge --prefix=<prefix> <commit>
git subtree split --prefix=<prefix> [<commit>]
git subtree pull  --prefix=<prefix> <repository> <ref>
git subtree push  --prefix=<prefix> <repository> <refspec>
--
h,help!       show the help
q,quiet!      quiet
d,debug!      show debug messages
P,prefix=     the name of the subdir to split out
 options for 'split' (also: 'push')
annotate=     add a prefix to commit message of new commits
b,branch!=    create a new branch from the split subtree
ignore-joins  ignore prior --rejoin commits
onto=         try connecting new tree to an existing one
rejoin        merge the new branch back into HEAD
 options for 'add' and 'merge' (also: 'pull', 'split --rejoin', and 'push --rejoin')
squash        merge subtree changes as a single commit
m,message!=   use the given message as the commit message for the merge commit
"

indent=0

# Usage: say [MSG...]
say () {
	if test -z "$arg_quiet"
	then
		printf '%s\n' "$*"
	fi
}

# Usage: debug [MSG...]
debug () {
	if test -n "$arg_debug"
	then
		printf "%$(($indent * 2))s%s\n" '' "$*" >&2
	fi
}

# Usage: progress [MSG...]
progress () {
	if test -z "$arg_quiet"
	then
		if test -z "$arg_debug"
		then
			# Debug mode is off.
			#
			# Print one progress line that we keep updating (use
			# "\r" to return to the beginning of the line, rather
			# than "\n" to start a new line).  This only really
			# works when stderr is a terminal.
			printf "%s\r" "$*" >&2
		else
			# Debug mode is on.  The `debug` function is regularly
			# printing to stderr.
			#
			# Don't do the one-line-with-"\r" thing, because on a
			# terminal the debug output would overwrite and hide the
			# progress output.  Add a "progress:" prefix to make the
			# progress output and the debug output easy to
			# distinguish.  This ensures maximum readability whether
			# stderr is a terminal or a file.
			printf "progress: %s\n" "$*" >&2
		fi
	fi
}

# Usage: assert CMD...
assert () {
	if ! "$@"
	then
		die "fatal: assertion failed: $*"
	fi
}

# Usage: die_incompatible_opt OPTION COMMAND
die_incompatible_opt () {
	assert test "$#" = 2
	opt="$1"
	arg_command="$2"
	die "fatal: the '$opt' flag does not make sense with 'git subtree $arg_command'."
}

main () {
	if test $# -eq 0
	then
		set -- -h
	fi
	set_args="$(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)"
	eval "$set_args"
	. git-sh-setup
	require_work_tree

# First figure out the command and whether we use --rejoin, so
	# that we can provide more helpful validation when we do the
	# "real" flag parsing.
	arg_split_rejoin=
	allow_split=
	allow_addmerge=
	while test $# -gt 0
	do
		opt="$1"
		shift
		case "$opt" in
			--annotate|-b|-P|-m|--onto)
				shift
				;;
			--rejoin)
				arg_split_rejoin=1
				;;
			--no-rejoin)
				arg_split_rejoin=
				;;
			--)
				break
				;;
		esac
	done
	arg_command=$1
	case "$arg_command" in
	add|merge|pull)
		allow_addmerge=1
		;;
	split|push)
		allow_split=1
		allow_addmerge=$arg_split_rejoin
		;;
	*)
		die "fatal: unknown command '$arg_command'"
		;;
	esac
	# Reset the arguments array for "real" flag parsing.
	eval "$set_args"

# Begin "real" flag parsing.
	arg_quiet=
	arg_debug=
	arg_prefix=
	arg_split_branch=
	arg_split_onto=
	arg_split_ignore_joins=
	arg_split_annotate=
	arg_addmerge_squash=
	arg_addmerge_message=
	while test $# -gt 0
	do
		opt="$1"
		shift

case "$opt" in
		-q)
			arg_quiet=1
			;;
		-d)
			arg_debug=1
			;;
		--annotate)
			test -n "$allow_split" || die_incompatible_opt "$opt" "$arg_command"
			arg_split_annotate="$1"
			shift
			;;
		--no-annotate)
			test -n "$allow_split" || die_incompatible_opt "$opt" "$arg_command"
			arg_split_annotate=
			;;
		-b)
			test -n "$allow_split" || die_incompatible_opt "$opt" "$arg_command"
			arg_split_branch="$1"
			shift
			;;
		-P)
			arg_prefix="${1%/}"
			shift
			;;
		-m)
			test -n "$allow_addmerge" || die_incompatible_opt "$opt" "$arg_command"
			arg_addmerge_message="$1"
			shift
			;;
		--no-prefix)
			arg_prefix=
			;;
		--onto)
			test -n "$allow_split" || die_incompatible_opt "$opt" "$arg_command"
			arg_split_onto="$1"
			shift
			;;
		--no-onto)
			test -n "$allow_split" || die_incompatible_opt "$opt" "$arg_command"
			arg_split_onto=
			;;
		--rejoin)
			test -n "$allow_split" || die_incompatible_opt "$opt" "$arg_command"
			;;
		--no-rejoin)
			test -n "$allow_split" || die_incompatible_opt "$opt" "$arg_command"
			;;
		--ignore-joins)
			test -n "$allow_split" || die_incompatible_opt "$opt" "$arg_command"
			arg_split_ignore_joins=1
			;;
		--no-ignore-joins)
			test -n "$allow_split" || die_incompatible_opt "$opt" "$arg_command"
			arg_split_ignore_joins=
			;;
		--squash)
			test -n "$allow_addmerge" || die_incompatible_opt "$opt" "$arg_command"
			arg_addmerge_squash=1
			;;
		--no-squash)
			test -n "$allow_addmerge" || die_incompatible_opt "$opt" "$arg_command"
			arg_addmerge_squash=
			;;
		--)
			break
			;;
		*)
			die "fatal: unexpected option: $opt"
			;;
		esac
	done
	shift

if test -z "$arg_prefix"
	then
		die "fatal: you must provide the --prefix option."
	fi

case "$arg_command" in
	add)
		test -e "$arg_prefix" &&
			die "fatal: prefix '$arg_prefix' already exists."
		;;
	*)
		test -e "$arg_prefix" ||
			die "fatal: '$arg_prefix' does not exist; use 'git subtree add'"
		;;
	esac

dir="$(dirname "$arg_prefix/.")"

debug "command: {$arg_command}"
	debug "quiet: {$arg_quiet}"
	debug "dir: {$dir}"
	debug "opts: {$*}"
	debug

"cmd_$arg_command" "$@"
}

# Usage: cache_setup
cache_setup () {
	assert test $# = 0
	cachedir="$GIT_DIR/subtree-cache/$$"
	rm -rf "$cachedir" ||
		die "fatal: can't delete old cachedir: $cachedir"
	mkdir -p "$cachedir" ||
		die "fatal: can't create new cachedir: $cachedir"
	mkdir -p "$cachedir/notree" ||
		die "fatal: can't create new cachedir: $cachedir/notree"
	debug "Using cachedir: $cachedir" >&2
}

# Usage: cache_get [REVS...]
cache_get () {
	for oldrev in "$@"
	do
		if test -r "$cachedir/$oldrev"
		then
			read newrev <"$cachedir/$oldrev"
			echo $newrev
		fi
	done
}

# Usage: cache_miss [REVS...]
cache_miss () {
	for oldrev in "$@"
	do
		if ! test -r "$cachedir/$oldrev"
		then
			echo $oldrev
		fi
	done
}

# Usage: check_parents [REVS...]
check_parents () {
	missed=$(cache_miss "$@") || exit $?
	local indent=$(($indent + 1))
	for miss in $missed
	do
		if ! test -r "$cachedir/notree/$miss"
		then
			debug "incorrect order: $miss"
			process_split_commit "$miss" ""
		fi
	done
}

# Usage: set_notree REV
set_notree () {
	assert test $# = 1
	echo "1" > "$cachedir/notree/$1"
}

# Usage: cache_set OLDREV NEWREV
cache_set () {
	assert test $# = 2
	oldrev="$1"
	newrev="$2"
	if test "$oldrev" != "latest_old" &&
		test "$oldrev" != "latest_new" &&
		test -e "$cachedir/$oldrev"
	then
		die "fatal: cache for $oldrev already exists!"
	fi
	echo "$newrev" >"$cachedir/$oldrev"
}

# Usage: rev_exists REV
rev_exists () {
	assert test $# = 1
	if git rev-parse "$1" >/dev/null 2>&1
	then
		return 0
	else
		return 1
	fi
}

# Usage: try_remove_previous REV
#
# If a commit doesn't have a parent, this might not work.  But we only want
# to remove the parent from the rev-list, and since it doesn't exist, it won't
# be there anyway, so do nothing in that case.
try_remove_previous () {
	assert test $# = 1
	if rev_exists "$1^"
	then
		echo "^$1^"
	fi
}

# Usage: process_subtree_split_trailer SPLIT_HASH MAIN_HASH [REPOSITORY]
process_subtree_split_trailer () {
	assert test $# = 2 -o $# = 3
	b="$1"
	sq="$2"
	repository=""
	if test "$#" = 3
	then
		repository="$3"
	fi
	fail_msg="fatal: could not rev-parse split hash $b from commit $sq"
	if ! sub="$(git rev-parse --verify --quiet "$b^{commit}")"
	then
		# if 'repository' was given, try to fetch the 'git-subtree-split' hash
		# before 'rev-parse'-ing it again, as it might be a tag that we do not have locally
		if test -n "${repository}"
		then
			git fetch "$repository" "$b"
			sub="$(git rev-parse --verify --quiet "$b^{commit}")" ||
				die "$fail_msg"
		else
			hint1=$(printf "hint: hash might be a tag, try fetching it from the subtree repository:")
			hint2=$(printf "hint:    git fetch <subtree-repository> $b")
			fail_msg=$(printf "$fail_msg\n$hint1\n$hint2")
			die "$fail_msg"
		fi
	fi
}

# Usage: find_latest_squash DIR [REPOSITORY]
find_latest_squash () {
	assert test $# = 1 -o $# = 2
	dir="$1"
	repository=""
	if test "$#" = 2
	then
		repository="$2"
	fi
	debug "Looking for latest squash (dir=$dir, repository=$repository)..."
	local indent=$(($indent + 1))

sq=
	main=
	sub=
	git log --grep="^git-subtree-dir: $dir/*\$" \
		--no-show-signature --pretty=format:'START %H%n%s%n%n%b%nEND%n' HEAD |
	while read a b junk
	do
		debug "$a $b $junk"
		debug "{{$sq/$main/$sub}}"
		case "$a" in
		START)
			sq="$b"
			;;
		git-subtree-mainline:)
			main="$b"
			;;
		git-subtree-split:)
			process_subtree_split_trailer "$b" "$sq" "$repository"
			;;
		END)
			if test -n "$sub"
			then
				if test -n "$main"
				then
					# a rejoin commit?
					# Pretend its sub was a squash.
					sq=$(git rev-parse --verify "$sq^2") ||
						die
				fi
				debug "Squash found: $sq $sub"
				echo "$sq" "$sub"
				break
			fi
			sq=
			main=
			sub=
			;;
		esac
	done || exit $?
}

# Usage: find_existing_splits DIR REV [REPOSITORY]
find_existing_splits () {
	assert test $# = 2 -o $# = 3
	debug "Looking for prior splits..."
	local indent=$(($indent + 1))

dir="$1"
	rev="$2"
	repository=""
	if test "$#" = 3
	then
		repository="$3"
	fi
	main=
	sub=
	local grep_format="^git-subtree-dir: $dir/*\$"
	if test -n "$arg_split_ignore_joins"
	then
		grep_format="^Add '$dir/' from commit '"
	fi
	git log --grep="$grep_format" \
		--no-show-signature --pretty=format:'START %H%n%s%n%n%b%nEND%n' "$rev" |
	while read a b junk
	do
		case "$a" in
		START)
			sq="$b"
			;;
		git-subtree-mainline:)
			main="$b"
			;;
		git-subtree-split:)
			process_subtree_split_trailer "$b" "$sq" "$repository"
			;;
		END)
			debug "Main is: '$main'"
			if test -z "$main" -a -n "$sub"
			then
				# squash commits refer to a subtree
				debug "  Squash: $sq from $sub"
				cache_set "$sq" "$sub"
			fi
			if test -n "$main" -a -n "$sub"
			then
				debug "  Prior: $main -> $sub"
				cache_set $main $sub
				cache_set $sub $sub
				try_remove_previous "$main"
				try_remove_previous "$sub"
			fi
			main=
			sub=
			;;
		esac
	done || exit $?
}

# Usage: copy_commit REV TREE FLAGS_STR
copy_commit () {
	assert test $# = 3
	# We're going to set some environment vars here, so
	# do it in a subshell to get rid of them safely later
	debug copy_commit "{$1}" "{$2}" "{$3}"
	git log -1 --no-show-signature --pretty=format:'%an%n%ae%n%aD%n%cn%n%ce%n%cD%n%B' "$1" |
	(
		read GIT_AUTHOR_NAME
		read GIT_AUTHOR_EMAIL
		read GIT_AUTHOR_DATE
		read GIT_COMMITTER_NAME
		read GIT_COMMITTER_EMAIL
		read GIT_COMMITTER_DATE
		export  GIT_AUTHOR_NAME \
			GIT_AUTHOR_EMAIL \
			GIT_AUTHOR_DATE \
			GIT_COMMITTER_NAME \
			GIT_COMMITTER_EMAIL \
			GIT_COMMITTER_DATE
		(
			printf "%s" "$arg_split_annotate"
			cat
		) |
		git commit-tree "$2" $3  # reads the rest of stdin
	) || die "fatal: can't copy commit $1"
}

# Usage: add_msg DIR LATEST_OLD LATEST_NEW
add_msg () {
	assert test $# = 3
	dir="$1"
	latest_old="$2"
	latest_new="$3"
	if test -n "$arg_addmerge_message"
	then
		commit_message="$arg_addmerge_message"
	else
		commit_message="Add '$dir/' from commit '$latest_new'"
	fi
	if test -n "$arg_split_rejoin"
	then
		# If this is from a --rejoin, then rejoin_msg has
		# already inserted the `git-subtree-xxx:` tags
		echo "$commit_message"
		return
	fi
	cat <<-EOF
		$commit_message

git-subtree-dir: $dir
		git-subtree-mainline: $latest_old
		git-subtree-split: $latest_new
	EOF
}

# Usage: add_squashed_msg REV DIR
add_squashed_msg () {
	assert test $# = 2
	if test -n "$arg_addmerge_message"
	then
		echo "$arg_addmerge_message"
	else
		echo "Merge commit '$1' as '$2'"
	fi
}

# Usage: rejoin_msg DIR LATEST_OLD LATEST_NEW
rejoin_msg () {
	assert test $# = 3
	dir="$1"
	latest_old="$2"
	latest_new="$3"
	if test -n "$arg_addmerge_message"
	then
		commit_message="$arg_addmerge_message"
	else
		commit_message="Split '$dir/' into commit '$latest_new'"
	fi
	cat <<-EOF
		$commit_message

git-subtree-dir: $dir
		git-subtree-mainline: $latest_old
		git-subtree-split: $latest_new
	EOF
}

# Usage: squash_msg DIR OLD_SUBTREE_COMMIT NEW_SUBTREE_COMMIT
squash_msg () {
	assert test $# = 3
	dir="$1"
	oldsub="$2"
	newsub="$3"
	newsub_short=$(git rev-parse --short "$newsub")

if test -n "$oldsub"
	then
		oldsub_short=$(git rev-parse --short "$oldsub")
		echo "Squashed '$dir/' changes from $oldsub_short..$newsub_short"
		echo
		git log --no-show-signature --pretty=tformat:'%h %s' "$oldsub..$newsub"
		git log --no-show-signature --pretty=tformat:'REVERT: %h %s' "$newsub..$oldsub"
	else
		echo "Squashed '$dir/' content from commit $newsub_short"
	fi

echo
	echo "git-subtree-dir: $dir"
	echo "git-subtree-split: $newsub"
}

# Usage: toptree_for_commit COMMIT
toptree_for_commit () {
	assert test $# = 1
	commit="$1"
	git rev-parse --verify "$commit^{tree}" || exit $?
}

# Usage: subtree_for_commit COMMIT DIR
subtree_for_commit () {
	assert test $# = 2
	commit="$1"
	dir="$2"
	git ls-tree "$commit" -- "$dir" |
	while read mode type tree name
	do
		assert test "$name" = "$dir"
		assert test "$type" = "tree" -o "$type" = "commit"
		test "$type" = "commit" && continue  # ignore submodules
		echo $tree
		break
	done || exit $?
}

# Usage: tree_changed TREE [PARENTS...]
tree_changed () {
	assert test $# -gt 0
	tree=$1
	shift
	if test $# -ne 1
	then
		return 0   # weird parents, consider it changed
	else
		ptree=$(toptree_for_commit $1) || exit $?
		if test "$ptree" != "$tree"
		then
			return 0   # changed
		else
			return 1   # not changed
		fi
	fi
}

# Usage: new_squash_commit OLD_SQUASHED_COMMIT OLD_NONSQUASHED_COMMIT NEW_NONSQUASHED_COMMIT
new_squash_commit () {
	assert test $# = 3
	old="$1"
	oldsub="$2"
	newsub="$3"
	tree=$(toptree_for_commit $newsub) || exit $?
	if test -n "$old"
	then
		squash_msg "$dir" "$oldsub" "$newsub" |
		git commit-tree "$tree" -p "$old" || exit $?
	else
		squash_msg "$dir" "" "$newsub" |
		git commit-tree "$tree" || exit $?
	fi
}

# Usage: copy_or_skip REV TREE NEWPARENTS
copy_or_skip () {
	assert test $# = 3
	rev="$1"
	tree="$2"
	newparents="$3"
	assert test -n "$tree"

identical=
	nonidentical=
	p=
	gotparents=
	copycommit=
	for parent in $newparents
	do
		ptree=$(toptree_for_commit $parent) || exit $?
		test -z "$ptree" && continue
		if test "$ptree" = "$tree"
		then
			# an identical parent could be used in place of this rev.
			if test -n "$identical"
			then
				# if a previous identical parent was found, check whether
				# one is already an ancestor of the other
				mergebase=$(git merge-base $identical $parent)
				if test "$identical" = "$mergebase"
				then
					# current identical commit is an ancestor of parent
					identical="$parent"
				elif test "$parent" != "$mergebase"
				then
					# no common history; commit must be copied
					copycommit=1
				fi
			else
				# first identical parent detected
				identical="$parent"
			fi
		else
			nonidentical="$parent"
		fi

# sometimes both old parents map to the same newparent;
		# eliminate duplicates
		is_new=1
		for gp in $gotparents
		do
			if test "$gp" = "$parent"
			then
				is_new=
				break
			fi
		done
		if test -n "$is_new"
		then
			gotparents="$gotparents $parent"
			p="$p -p $parent"
		fi
	done

if test -n "$identical" && test -n "$nonidentical"
	then
		extras=$(git rev-list --count $identical..$nonidentical)
		if test "$extras" -ne 0
		then
			# we need to preserve history along the other branch
			copycommit=1
		fi
	fi
	if test -n "$identical" && test -z "$copycommit"
	then
		echo $identical
	else
		copy_commit "$rev" "$tree" "$p" || exit $?
	fi
}

# Usage: ensure_clean
ensure_clean () {
	assert test $# = 0
	if ! git diff-index HEAD --exit-code --quiet 2>&1
	then
		die "fatal: working tree has modifications.  Cannot add."
	fi
	if ! git diff-index --cached HEAD --exit-code --quiet 2>&1
	then
		die "fatal: index has modifications.  Cannot add."
	fi
}

# Usage: ensure_valid_ref_format REF
ensure_valid_ref_format () {
	assert test $# = 1
	git check-ref-format "refs/heads/$1" ||
		die "fatal: '$1' does not look like a ref"
}

# Usage: process_split_commit REV PARENTS
process_split_commit () {
	assert test $# = 2
	local rev="$1"
	local parents="$2"

if test $indent -eq 0
	then
		revcount=$(($revcount + 1))
	else
		# processing commit without normal parent information;
		# fetch from repo
		parents=$(git rev-parse "$rev^@")
		extracount=$(($extracount + 1))
	fi

progress "$revcount/$revmax ($createcount) [$extracount]"

debug "Processing commit: $rev"
	local indent=$(($indent + 1))
	exists=$(cache_get "$rev") || exit $?
	if test -n "$exists"
	then
		debug "prior: $exists"
		return
	fi
	createcount=$(($createcount + 1))
	debug "parents: $parents"
	check_parents $parents
	newparents=$(cache_get $parents) || exit $?
	debug "newparents: $newparents"

tree=$(subtree_for_commit "$rev" "$dir") || exit $?
	debug "tree is: $tree"

# ugly.  is there no better way to tell if this is a subtree
	# vs. a mainline commit?  Does it matter?
	if test -z "$tree"
	then
		set_notree "$rev"
		if test -n "$newparents"
		then
			cache_set "$rev" "$rev"
		fi
		return
	fi

newrev=$(copy_or_skip "$rev" "$tree" "$newparents") || exit $?
	debug "newrev is: $newrev"
	cache_set "$rev" "$newrev"
	cache_set latest_new "$newrev"
	cache_set latest_old "$rev"
}

# Usage: cmd_add REV
#    Or: cmd_add REPOSITORY REF
cmd_add () {

ensure_clean

if test $# -eq 1
	then
		git rev-parse -q --verify "$1^{commit}" >/dev/null ||
			die "fatal: '$1' does not refer to a commit"

cmd_add_commit "$@"

elif test $# -eq 2
	then
		# Technically we could accept a refspec here but we're
		# just going to turn around and add FETCH_HEAD under the
		# specified directory.  Allowing a refspec might be
		# misleading because we won't do anything with any other
		# branches fetched via the refspec.
		ensure_valid_ref_format "$2"

cmd_add_repository "$@"
	else
		say >&2 "fatal: parameters were '$*'"
		die "Provide either a commit or a repository and commit."
	fi
}

# Usage: cmd_add_repository REPOSITORY REFSPEC
cmd_add_repository () {
	assert test $# = 2
	echo "git fetch" "$@"
	repository=$1
	refspec=$2
	git fetch "$@" || exit $?
	cmd_add_commit FETCH_HEAD
}

# Usage: cmd_add_commit REV
cmd_add_commit () {
	# The rev has already been validated by cmd_add(), we just
	# need to normalize it.
	assert test $# = 1
	rev=$(git rev-parse --verify "$1^{commit}") || exit $?

debug "Adding $dir as '$rev'..."
	if test -z "$arg_split_rejoin"
	then
		# Only bother doing this if this is a genuine 'add',
		# not a synthetic 'add' from '--rejoin'.
		git read-tree --prefix="$dir" $rev || exit $?
	fi
	git checkout -- "$dir" || exit $?
	tree=$(git write-tree) || exit $?

headrev=$(git rev-parse --verify HEAD) || exit $?
	if test -n "$headrev" && test "$headrev" != "$rev"
	then
		headp="-p $headrev"
	else
		headp=
	fi

if test -n "$arg_addmerge_squash"
	then
		rev=$(new_squash_commit "" "" "$rev") || exit $?
		commit=$(add_squashed_msg "$rev" "$dir" |
			git commit-tree "$tree" $headp -p "$rev") || exit $?
	else
		revp=$(peel_committish "$rev") || exit $?
		commit=$(add_msg "$dir" $headrev "$rev" |
			git commit-tree "$tree" $headp -p "$revp") || exit $?
	fi
	git reset "$commit" || exit $?

say >&2 "Added dir '$dir'"
}

# Usage: cmd_split [REV] [REPOSITORY]
cmd_split () {
	if test $# -eq 0
	then
		rev=$(git rev-parse HEAD)
	elif test $# -eq 1 -o $# -eq 2
	then
		rev=$(git rev-parse -q --verify "$1^{commit}") ||
			die "fatal: '$1' does not refer to a commit"
	else
		die "fatal: you must provide exactly one revision, and optionnally a repository.  Got: '$*'"
	fi
	repository=""
	if test "$#" = 2
	then
		repository="$2"
	fi

if test -n "$arg_split_rejoin"
	then
		ensure_clean
	fi

debug "Splitting $dir..."
	cache_setup || exit $?

if test -n "$arg_split_onto"
	then
		debug "Reading history for --onto=$arg_split_onto..."
		git rev-list $arg_split_onto |
		while read rev
		do
			# the 'onto' history is already just the subdir, so
			# any parent we find there can be used verbatim
			debug "cache: $rev"
			cache_set "$rev" "$rev"
		done || exit $?
	fi

unrevs="$(find_existing_splits "$dir" "$rev" "$repository")" || exit $?

# We can't restrict rev-list to only $dir here, because some of our
	# parents have the $dir contents the root, and those won't match.
	# (and rev-list --follow doesn't seem to solve this)
	grl='git rev-list --topo-order --reverse --parents $rev $unrevs'
	revmax=$(eval "$grl" | wc -l)
	revcount=0
	createcount=0
	extracount=0
	eval "$grl" |
	while read rev parents
	do
		process_split_commit "$rev" "$parents"
	done || exit $?

latest_new=$(cache_get latest_new) || exit $?
	if test -z "$latest_new"
	then
		die "fatal: no new revisions were found"
	fi

if test -n "$arg_split_rejoin"
	then
		debug "Merging split branch into HEAD..."
		latest_old=$(cache_get latest_old) || exit $?
		arg_addmerge_message="$(rejoin_msg "$dir" "$latest_old" "$latest_new")" || exit $?
		if test -z "$(find_latest_squash "$dir")"
		then
			cmd_add "$latest_new" >&2 || exit $?
		else
			cmd_merge "$latest_new" >&2 || exit $?
		fi
	fi
	if test -n "$arg_split_branch"
	then
		if rev_exists "refs/heads/$arg_split_branch"
		then
			if ! git merge-base --is-ancestor "$arg_split_branch" "$latest_new"
			then
				die "fatal: branch '$arg_split_branch' is not an ancestor of commit '$latest_new'."
			fi
			action='Updated'
		else
			action='Created'
		fi
		git update-ref -m 'subtree split' \
			"refs/heads/$arg_split_branch" "$latest_new" || exit $?
		say >&2 "$action branch '$arg_split_branch'"
	fi
	echo "$latest_new"
	exit 0
}

# Usage: cmd_merge REV [REPOSITORY]
cmd_merge () {
	test $# -eq 1 -o $# -eq 2 ||
		die "fatal: you must provide exactly one revision, and optionally a repository. Got: '$*'"
	rev=$(git rev-parse -q --verify "$1^{commit}") ||
		die "fatal: '$1' does not refer to a commit"
	repository=""
	if test "$#" = 2
	then
		repository="$2"
	fi
	ensure_clean

if test -n "$arg_addmerge_squash"
	then
		first_split="$(find_latest_squash "$dir" "$repository")" || exit $?
		if test -z "$first_split"
		then
			die "fatal: can't squash-merge: '$dir' was never added."
		fi
		set $first_split
		old=$1
		sub=$2
		if test "$sub" = "$rev"
		then
			say >&2 "Subtree is already at commit $rev."
			exit 0
		fi
		new=$(new_squash_commit "$old" "$sub" "$rev") || exit $?
		debug "New squash commit: $new"
		rev="$new"
	fi

if test -n "$arg_addmerge_message"
	then
		git merge --no-ff -Xsubtree="$arg_prefix" \
			--message="$arg_addmerge_message" "$rev"
	else
		git merge --no-ff -Xsubtree="$arg_prefix" $rev
	fi
}

# Usage: cmd_pull REPOSITORY REMOTEREF
cmd_pull () {
	if test $# -ne 2
	then
		die "fatal: you must provide <repository> <ref>"
	fi
	repository="$1"
	ref="$2"
	ensure_clean
	ensure_valid_ref_format "$ref"
	git fetch "$repository" "$ref" || exit $?
	cmd_merge FETCH_HEAD "$repository"
}

# Usage: cmd_push REPOSITORY [+][LOCALREV:]REMOTEREF
cmd_push () {
	if test $# -ne 2
	then
		die "fatal: you must provide <repository> <refspec>"
	fi
	if test -e "$dir"
	then
		repository=$1
		refspec=${2#+}
		remoteref=${refspec#*:}
		if test "$remoteref" = "$refspec"
		then
			localrevname_presplit=HEAD
		else
			localrevname_presplit=${refspec%%:*}
		fi
		ensure_valid_ref_format "$remoteref"
		localrev_presplit=$(git rev-parse -q --verify "$localrevname_presplit^{commit}") ||
			die "fatal: '$localrevname_presplit' does not refer to a commit"

echo "git push using: " "$repository" "$refspec"
		localrev=$(cmd_split "$localrev_presplit" "$repository") || die
		git push "$repository" "$localrev":"refs/heads/$remoteref"
	else
		die "fatal: '$dir' must already exist. Try 'git subtree add'."
	fi
}

main "$@"

cmd: