Squashed 'third_party/git/' content from commit cb71568594

git-subtree-dir: third_party/git
git-subtree-split: cb715685942260375e1eb8153b0768a376e4ece7

1 files changed, 901 insertions, 0 deletions

diff --git a/contrib/subtree/git-subtree.sh b/contrib/subtree/git-subtree.sh
new file mode 100755
index 000000000000..868e18b9a1ab
--- /dev/null
+++ b/contrib/subtree/git-subtree.sh
@@ -0,0 +1,901 @@
+#!/bin/sh
+#
+# git-subtree.sh: split/join git repositories in subdirectories of this one
+#
+# Copyright (C) 2009 Avery Pennarun <apenwarr@gmail.com>
+#
+if test $# -eq 0
+then
+	set -- -h
+fi
+OPTS_SPEC="\
+git subtree add   --prefix=<prefix> <commit>
+git subtree add   --prefix=<prefix> <repository> <ref>
+git subtree merge --prefix=<prefix> <commit>
+git subtree pull  --prefix=<prefix> <repository> <ref>
+git subtree push  --prefix=<prefix> <repository> <ref>
+git subtree split --prefix=<prefix> <commit>
+--
+h,help        show the help
+q             quiet
+d             show debug messages
+P,prefix=     the name of the subdir to split out
+m,message=    use the given message as the commit message for the merge commit
+ options for 'split'
+annotate=     add a prefix to commit message of new commits
+b,branch=     create a new branch from the split subtree
+ignore-joins  ignore prior --rejoin commits
+onto=         try connecting new tree to an existing one
+rejoin        merge the new branch back into HEAD
+ options for 'add', 'merge', and 'pull'
+squash        merge subtree changes as a single commit
+"
+eval "$(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)"
+
+PATH=$PATH:$(git --exec-path)
+. git-sh-setup
+
+require_work_tree
+
+quiet=
+branch=
+debug=
+command=
+onto=
+rejoin=
+ignore_joins=
+annotate=
+squash=
+message=
+prefix=
+
+debug () {
+	if test -n "$debug"
+	then
+		printf "%s\n" "$*" >&2
+	fi
+}
+
+say () {
+	if test -z "$quiet"
+	then
+		printf "%s\n" "$*" >&2
+	fi
+}
+
+progress () {
+	if test -z "$quiet"
+	then
+		printf "%s\r" "$*" >&2
+	fi
+}
+
+assert () {
+	if ! "$@"
+	then
+		die "assertion failed: " "$@"
+	fi
+}
+
+ensure_single_rev () {
+	if test $# -ne 1
+	then
+		die "You must provide exactly one revision.  Got: '$@'"
+	fi
+}
+
+while test $# -gt 0
+do
+	opt="$1"
+	shift
+
+	case "$opt" in
+	-q)
+		quiet=1
+		;;
+	-d)
+		debug=1
+		;;
+	--annotate)
+		annotate="$1"
+		shift
+		;;
+	--no-annotate)
+		annotate=
+		;;
+	-b)
+		branch="$1"
+		shift
+		;;
+	-P)
+		prefix="${1%/}"
+		shift
+		;;
+	-m)
+		message="$1"
+		shift
+		;;
+	--no-prefix)
+		prefix=
+		;;
+	--onto)
+		onto="$1"
+		shift
+		;;
+	--no-onto)
+		onto=
+		;;
+	--rejoin)
+		rejoin=1
+		;;
+	--no-rejoin)
+		rejoin=
+		;;
+	--ignore-joins)
+		ignore_joins=1
+		;;
+	--no-ignore-joins)
+		ignore_joins=
+		;;
+	--squash)
+		squash=1
+		;;
+	--no-squash)
+		squash=
+		;;
+	--)
+		break
+		;;
+	*)
+		die "Unexpected option: $opt"
+		;;
+	esac
+done
+
+command="$1"
+shift
+
+case "$command" in
+add|merge|pull)
+	default=
+	;;
+split|push)
+	default="--default HEAD"
+	;;
+*)
+	die "Unknown command '$command'"
+	;;
+esac
+
+if test -z "$prefix"
+then
+	die "You must provide the --prefix option."
+fi
+
+case "$command" in
+add)
+	test -e "$prefix" &&
+		die "prefix '$prefix' already exists."
+	;;
+*)
+	test -e "$prefix" ||
+		die "'$prefix' does not exist; use 'git subtree add'"
+	;;
+esac
+
+dir="$(dirname "$prefix/.")"
+
+if test "$command" != "pull" &&
+		test "$command" != "add" &&
+		test "$command" != "push"
+then
+	revs=$(git rev-parse $default --revs-only "$@") || exit $?
+	dirs=$(git rev-parse --no-revs --no-flags "$@") || exit $?
+	ensure_single_rev $revs
+	if test -n "$dirs"
+	then
+		die "Error: Use --prefix instead of bare filenames."
+	fi
+fi
+
+debug "command: {$command}"
+debug "quiet: {$quiet}"
+debug "revs: {$revs}"
+debug "dir: {$dir}"
+debug "opts: {$*}"
+debug
+
+cache_setup () {
+	cachedir="$GIT_DIR/subtree-cache/$$"
+	rm -rf "$cachedir" ||
+		die "Can't delete old cachedir: $cachedir"
+	mkdir -p "$cachedir" ||
+		die "Can't create new cachedir: $cachedir"
+	mkdir -p "$cachedir/notree" ||
+		die "Can't create new cachedir: $cachedir/notree"
+	debug "Using cachedir: $cachedir" >&2
+}
+
+cache_get () {
+	for oldrev in "$@"
+	do
+		if test -r "$cachedir/$oldrev"
+		then
+			read newrev <"$cachedir/$oldrev"
+			echo $newrev
+		fi
+	done
+}
+
+cache_miss () {
+	for oldrev in "$@"
+	do
+		if ! test -r "$cachedir/$oldrev"
+		then
+			echo $oldrev
+		fi
+	done
+}
+
+check_parents () {
+	missed=$(cache_miss "$1")
+	local indent=$(($2 + 1))
+	for miss in $missed
+	do
+		if ! test -r "$cachedir/notree/$miss"
+		then
+			debug "  incorrect order: $miss"
+			process_split_commit "$miss" "" "$indent"
+		fi
+	done
+}
+
+set_notree () {
+	echo "1" > "$cachedir/notree/$1"
+}
+
+cache_set () {
+	oldrev="$1"
+	newrev="$2"
+	if test "$oldrev" != "latest_old" &&
+		test "$oldrev" != "latest_new" &&
+		test -e "$cachedir/$oldrev"
+	then
+		die "cache for $oldrev already exists!"
+	fi
+	echo "$newrev" >"$cachedir/$oldrev"
+}
+
+rev_exists () {
+	if git rev-parse "$1" >/dev/null 2>&1
+	then
+		return 0
+	else
+		return 1
+	fi
+}
+
+rev_is_descendant_of_branch () {
+	newrev="$1"
+	branch="$2"
+	branch_hash=$(git rev-parse "$branch")
+	match=$(git rev-list -1 "$branch_hash" "^$newrev")
+
+	if test -z "$match"
+	then
+		return 0
+	else
+		return 1
+	fi
+}
+
+# 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 () {
+	if rev_exists "$1^"
+	then
+		echo "^$1^"
+	fi
+}
+
+find_latest_squash () {
+	debug "Looking for latest squash ($dir)..."
+	dir="$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="$b"
+			;;
+		git-subtree-split:)
+			sub="$(git rev-parse "$b^0")" ||
+			die "could not rev-parse split hash $b from commit $sq"
+			;;
+		END)
+			if test -n "$sub"
+			then
+				if test -n "$main"
+				then
+					# a rejoin commit?
+					# Pretend its sub was a squash.
+					sq="$sub"
+				fi
+				debug "Squash found: $sq $sub"
+				echo "$sq" "$sub"
+				break
+			fi
+			sq=
+			main=
+			sub=
+			;;
+		esac
+	done
+}
+
+find_existing_splits () {
+	debug "Looking for prior splits..."
+	dir="$1"
+	revs="$2"
+	main=
+	sub=
+	local grep_format="^git-subtree-dir: $dir/*\$"
+	if test -n "$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' $revs |
+	while read a b junk
+	do
+		case "$a" in
+		START)
+			sq="$b"
+			;;
+		git-subtree-mainline:)
+			main="$b"
+			;;
+		git-subtree-split:)
+			sub="$(git rev-parse "$b^0")" ||
+			die "could not rev-parse split hash $b from commit $sq"
+			;;
+		END)
+			debug "  Main is: '$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
+}
+
+copy_commit () {
+	# 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' "$1" |
+	(
+		read GIT_AUTHOR_NAME
+		read GIT_AUTHOR_EMAIL
+		read GIT_AUTHOR_DATE
+		read GIT_COMMITTER_NAME
+		read GIT_COMMITTER_EMAIL
+		read GIT_COMMITTER_DATE
+		export  GIT_AUTHOR_NAME \
+			GIT_AUTHOR_EMAIL \
+			GIT_AUTHOR_DATE \
+			GIT_COMMITTER_NAME \
+			GIT_COMMITTER_EMAIL \
+			GIT_COMMITTER_DATE
+		(
+			printf "%s" "$annotate"
+			cat
+		) |
+		git commit-tree "$2" $3  # reads the rest of stdin
+	) || die "Can't copy commit $1"
+}
+
+add_msg () {
+	dir="$1"
+	latest_old="$2"
+	latest_new="$3"
+	if test -n "$message"
+	then
+		commit_message="$message"
+	else
+		commit_message="Add '$dir/' from commit '$latest_new'"
+	fi
+	cat <<-EOF
+		$commit_message
+
+		git-subtree-dir: $dir
+		git-subtree-mainline: $latest_old
+		git-subtree-split: $latest_new
+	EOF
+}
+
+add_squashed_msg () {
+	if test -n "$message"
+	then
+		echo "$message"
+	else
+		echo "Merge commit '$1' as '$2'"
+	fi
+}
+
+rejoin_msg () {
+	dir="$1"
+	latest_old="$2"
+	latest_new="$3"
+	if test -n "$message"
+	then
+		commit_message="$message"
+	else
+		commit_message="Split '$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
+}
+
+squash_msg () {
+	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"
+}
+
+toptree_for_commit () {
+	commit="$1"
+	git rev-parse --verify "$commit^{tree}" || exit $?
+}
+
+subtree_for_commit () {
+	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
+}
+
+tree_changed () {
+	tree=$1
+	shift
+	if test $# -ne 1
+	then
+		return 0   # weird parents, consider it changed
+	else
+		ptree=$(toptree_for_commit $1)
+		if test "$ptree" != "$tree"
+		then
+			return 0   # changed
+		else
+			return 1   # not changed
+		fi
+	fi
+}
+
+new_squash_commit () {
+	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
+}
+
+copy_or_skip () {
+	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
+}
+
+ensure_clean () {
+	if ! git diff-index HEAD --exit-code --quiet 2>&1
+	then
+		die "Working tree has modifications.  Cannot add."
+	fi
+	if ! git diff-index --cached HEAD --exit-code --quiet 2>&1
+	then
+		die "Index has modifications.  Cannot add."
+	fi
+}
+
+ensure_valid_ref_format () {
+	git check-ref-format "refs/heads/$1" ||
+		die "'$1' does not look like a ref"
+}
+
+process_split_commit () {
+	local rev="$1"
+	local parents="$2"
+	local indent=$3
+
+	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: $rev"
+	exists=$(cache_get "$rev")
+	if test -n "$exists"
+	then
+		debug "  prior: $exists"
+		return
+	fi
+	createcount=$(($createcount + 1))
+	debug "  parents: $parents"
+	check_parents "$parents" "$indent"
+	newparents=$(cache_get $parents)
+	debug "  newparents: $newparents"
+
+	tree=$(subtree_for_commit "$rev" "$dir")
+	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 "$rev"
+}
+
+cmd_add () {
+	if test -e "$dir"
+	then
+		die "'$dir' already exists.  Cannot add."
+	fi
+
+	ensure_clean
+
+	if test $# -eq 1
+	then
+		git rev-parse -q --verify "$1^{commit}" >/dev/null ||
+			die "'$1' does not refer to a commit"
+
+		cmd_add_commit "$@"
+
+	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 "error: parameters were '$@'"
+		die "Provide either a commit or a repository and commit."
+	fi
+}
+
+cmd_add_repository () {
+	echo "git fetch" "$@"
+	repository=$1
+	refspec=$2
+	git fetch "$@" || exit $?
+	revs=FETCH_HEAD
+	set -- $revs
+	cmd_add_commit "$@"
+}
+
+cmd_add_commit () {
+	rev=$(git rev-parse $default --revs-only "$@") || exit $?
+	ensure_single_rev $rev
+
+	debug "Adding $dir as '$rev'..."
+	git read-tree --prefix="$dir" $rev || exit $?
+	git checkout -- "$dir" || exit $?
+	tree=$(git write-tree) || exit $?
+
+	headrev=$(git rev-parse HEAD) || exit $?
+	if test -n "$headrev" && test "$headrev" != "$rev"
+	then
+		headp="-p $headrev"
+	else
+		headp=
+	fi
+
+	if test -n "$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 "$rev") &&
+		commit=$(add_msg "$dir" $headrev "$rev" |
+			git commit-tree "$tree" $headp -p "$revp") || exit $?
+	fi
+	git reset "$commit" || exit $?
+
+	say "Added dir '$dir'"
+}
+
+cmd_split () {
+	debug "Splitting $dir..."
+	cache_setup || exit $?
+
+	if test -n "$onto"
+	then
+		debug "Reading history for --onto=$onto..."
+		git rev-list $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" "$rev"
+		done
+	fi
+
+	unrevs="$(find_existing_splits "$dir" "$revs")"
+
+	# 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 $revs $unrevs'
+	revmax=$(eval "$grl" | wc -l)
+	revcount=0
+	createcount=0
+	extracount=0
+	eval "$grl" |
+	while read rev parents
+	do
+		process_split_commit "$rev" "$parents" 0
+	done || exit $?
+
+	latest_new=$(cache_get latest_new)
+	if test -z "$latest_new"
+	then
+		die "No new revisions were found"
+	fi
+
+	if test -n "$rejoin"
+	then
+		debug "Merging split branch into HEAD..."
+		latest_old=$(cache_get latest_old)
+		git merge -s ours \
+			--allow-unrelated-histories \
+			-m "$(rejoin_msg "$dir" "$latest_old" "$latest_new")" \
+			"$latest_new" >&2 || exit $?
+	fi
+	if test -n "$branch"
+	then
+		if rev_exists "refs/heads/$branch"
+		then
+			if ! rev_is_descendant_of_branch "$latest_new" "$branch"
+			then
+				die "Branch '$branch' is not an ancestor of commit '$latest_new'."
+			fi
+			action='Updated'
+		else
+			action='Created'
+		fi
+		git update-ref -m 'subtree split' \
+			"refs/heads/$branch" "$latest_new" || exit $?
+		say "$action branch '$branch'"
+	fi
+	echo "$latest_new"
+	exit 0
+}
+
+cmd_merge () {
+	rev=$(git rev-parse $default --revs-only "$@") || exit $?
+	ensure_single_rev $rev
+	ensure_clean
+
+	if test -n "$squash"
+	then
+		first_split="$(find_latest_squash "$dir")"
+		if test -z "$first_split"
+		then
+			die "Can't squash-merge: '$dir' was never added."
+		fi
+		set $first_split
+		old=$1
+		sub=$2
+		if test "$sub" = "$rev"
+		then
+			say "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
+
+	version=$(git version)
+	if test "$version" \< "git version 1.7"
+	then
+		if test -n "$message"
+		then
+			git merge -s subtree --message="$message" "$rev"
+		else
+			git merge -s subtree "$rev"
+		fi
+	else
+		if test -n "$message"
+		then
+			git merge -Xsubtree="$prefix" \
+				--message="$message" "$rev"
+		else
+			git merge -Xsubtree="$prefix" $rev
+		fi
+	fi
+}
+
+cmd_pull () {
+	if test $# -ne 2
+	then
+		die "You must provide <repository> <ref>"
+	fi
+	ensure_clean
+	ensure_valid_ref_format "$2"
+	git fetch "$@" || exit $?
+	revs=FETCH_HEAD
+	set -- $revs
+	cmd_merge "$@"
+}
+
+cmd_push () {
+	if test $# -ne 2
+	then
+		die "You must provide <repository> <ref>"
+	fi
+	ensure_valid_ref_format "$2"
+	if test -e "$dir"
+	then
+		repository=$1
+		refspec=$2
+		echo "git push using: " "$repository" "$refspec"
+		localrev=$(git subtree split --prefix="$prefix") || die
+		git push "$repository" "$localrev":"refs/heads/$refspec"
+	else
+		die "'$dir' must already exist. Try 'git subtree add'."
+	fi
+}
+
+"cmd_$command" "$@"