stash: optionally use the scripted version again

We recently converted the `git stash` command from Unix shell scripts
to builtins.

Let's end users a way out when they discover a bug in the
builtin command: `stash.useBuiltin`.

As the file name `git-stash` is already in use, let's rename the
scripted backend to `git-legacy-stash`.

To make the test suite pass with `stash.useBuiltin=false`, this commit
also backports rudimentary support for `-q` (but only *just* enough
to appease the test suite), and adds a super-ugly hack to force exit
code 129 for `git stash -h`.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 797 insertions, 0 deletions

diff --git a/git-legacy-stash.sh b/git-legacy-stash.sh
new file mode 100755
index 0000000..8a8c4a9
--- /dev/null
+++ b/git-legacy-stash.sh
@@ -0,0 +1,797 @@
+#!/bin/sh
+# Copyright (c) 2007, Nanako Shiraishi
+
+dashless=$(basename "$0" | sed -e 's/-/ /')
+USAGE="list [<options>]
+   or: $dashless show [<stash>]
+   or: $dashless drop [-q|--quiet] [<stash>]
+   or: $dashless ( pop | apply ) [--index] [-q|--quiet] [<stash>]
+   or: $dashless branch <branchname> [<stash>]
+   or: $dashless save [--patch] [-k|--[no-]keep-index] [-q|--quiet]
+		      [-u|--include-untracked] [-a|--all] [<message>]
+   or: $dashless [push [--patch] [-k|--[no-]keep-index] [-q|--quiet]
+		       [-u|--include-untracked] [-a|--all] [-m <message>]
+		       [-- <pathspec>...]]
+   or: $dashless clear"
+
+SUBDIRECTORY_OK=Yes
+OPTIONS_SPEC=
+START_DIR=$(pwd)
+. git-sh-setup
+require_work_tree
+prefix=$(git rev-parse --show-prefix) || exit 1
+cd_to_toplevel
+
+TMP="$GIT_DIR/.git-stash.$$"
+TMPindex=${GIT_INDEX_FILE-"$(git rev-parse --git-path index)"}.stash.$$
+trap 'rm -f "$TMP-"* "$TMPindex"' 0
+
+ref_stash=refs/stash
+
+if git config --get-colorbool color.interactive; then
+       help_color="$(git config --get-color color.interactive.help 'red bold')"
+       reset_color="$(git config --get-color '' reset)"
+else
+       help_color=
+       reset_color=
+fi
+
+no_changes () {
+	git diff-index --quiet --cached HEAD --ignore-submodules -- "$@" &&
+	git diff-files --quiet --ignore-submodules -- "$@" &&
+	(test -z "$untracked" || test -z "$(untracked_files "$@")")
+}
+
+untracked_files () {
+	if test "$1" = "-z"
+	then
+		shift
+		z=-z
+	else
+		z=
+	fi
+	excl_opt=--exclude-standard
+	test "$untracked" = "all" && excl_opt=
+	git ls-files -o $z $excl_opt -- "$@"
+}
+
+prepare_fallback_ident () {
+	if ! git -c user.useconfigonly=yes var GIT_COMMITTER_IDENT >/dev/null 2>&1
+	then
+		GIT_AUTHOR_NAME="git stash"
+		GIT_AUTHOR_EMAIL=git@stash
+		GIT_COMMITTER_NAME="git stash"
+		GIT_COMMITTER_EMAIL=git@stash
+		export GIT_AUTHOR_NAME
+		export GIT_AUTHOR_EMAIL
+		export GIT_COMMITTER_NAME
+		export GIT_COMMITTER_EMAIL
+	fi
+}
+
+clear_stash () {
+	if test $# != 0
+	then
+		die "$(gettext "git stash clear with parameters is unimplemented")"
+	fi
+	if current=$(git rev-parse --verify --quiet $ref_stash)
+	then
+		git update-ref -d $ref_stash $current
+	fi
+}
+
+maybe_quiet () {
+	case "$1" in
+	--keep-stdout)
+		shift
+		if test -n "$GIT_QUIET"
+		then
+			eval "$@" 2>/dev/null
+		else
+			eval "$@"
+		fi
+		;;
+	*)
+		if test -n "$GIT_QUIET"
+		then
+			eval "$@" >/dev/null 2>&1
+		else
+			eval "$@"
+		fi
+		;;
+	esac
+}
+
+create_stash () {
+
+	prepare_fallback_ident
+
+	stash_msg=
+	untracked=
+	while test $# != 0
+	do
+		case "$1" in
+		-m|--message)
+			shift
+			stash_msg=${1?"BUG: create_stash () -m requires an argument"}
+			;;
+		-m*)
+			stash_msg=${1#-m}
+			;;
+		--message=*)
+			stash_msg=${1#--message=}
+			;;
+		-u|--include-untracked)
+			shift
+			untracked=${1?"BUG: create_stash () -u requires an argument"}
+			;;
+		--)
+			shift
+			break
+			;;
+		esac
+		shift
+	done
+
+	git update-index -q --refresh
+	if maybe_quiet no_changes "$@"
+	then
+		exit 0
+	fi
+
+	# state of the base commit
+	if b_commit=$(maybe_quiet --keep-stdout git rev-parse --verify HEAD)
+	then
+		head=$(git rev-list --oneline -n 1 HEAD --)
+	elif test -n "$GIT_QUIET"
+	then
+		exit 1
+	else
+		die "$(gettext "You do not have the initial commit yet")"
+	fi
+
+	if branch=$(git symbolic-ref -q HEAD)
+	then
+		branch=${branch#refs/heads/}
+	else
+		branch='(no branch)'
+	fi
+	msg=$(printf '%s: %s' "$branch" "$head")
+
+	# state of the index
+	i_tree=$(git write-tree) &&
+	i_commit=$(printf 'index on %s\n' "$msg" |
+		git commit-tree $i_tree -p $b_commit) ||
+		die "$(gettext "Cannot save the current index state")"
+
+	if test -n "$untracked"
+	then
+		# Untracked files are stored by themselves in a parentless commit, for
+		# ease of unpacking later.
+		u_commit=$(
+			untracked_files -z "$@" | (
+				GIT_INDEX_FILE="$TMPindex" &&
+				export GIT_INDEX_FILE &&
+				rm -f "$TMPindex" &&
+				git update-index -z --add --remove --stdin &&
+				u_tree=$(git write-tree) &&
+				printf 'untracked files on %s\n' "$msg" | git commit-tree $u_tree  &&
+				rm -f "$TMPindex"
+		) ) || die "$(gettext "Cannot save the untracked files")"
+
+		untracked_commit_option="-p $u_commit";
+	else
+		untracked_commit_option=
+	fi
+
+	if test -z "$patch_mode"
+	then
+
+		# state of the working tree
+		w_tree=$( (
+			git read-tree --index-output="$TMPindex" -m $i_tree &&
+			GIT_INDEX_FILE="$TMPindex" &&
+			export GIT_INDEX_FILE &&
+			git diff-index --name-only -z HEAD -- "$@" >"$TMP-stagenames" &&
+			git update-index -z --add --remove --stdin <"$TMP-stagenames" &&
+			git write-tree &&
+			rm -f "$TMPindex"
+		) ) ||
+			die "$(gettext "Cannot save the current worktree state")"
+
+	else
+
+		rm -f "$TMP-index" &&
+		GIT_INDEX_FILE="$TMP-index" git read-tree HEAD &&
+
+		# find out what the user wants
+		GIT_INDEX_FILE="$TMP-index" \
+			git add--interactive --patch=stash -- "$@" &&
+
+		# state of the working tree
+		w_tree=$(GIT_INDEX_FILE="$TMP-index" git write-tree) ||
+		die "$(gettext "Cannot save the current worktree state")"
+
+		git diff-tree -p HEAD $w_tree -- >"$TMP-patch" &&
+		test -s "$TMP-patch" ||
+		die "$(gettext "No changes selected")"
+
+		rm -f "$TMP-index" ||
+		die "$(gettext "Cannot remove temporary index (can't happen)")"
+
+	fi
+
+	# create the stash
+	if test -z "$stash_msg"
+	then
+		stash_msg=$(printf 'WIP on %s' "$msg")
+	else
+		stash_msg=$(printf 'On %s: %s' "$branch" "$stash_msg")
+	fi
+	w_commit=$(printf '%s\n' "$stash_msg" |
+	git commit-tree $w_tree -p $b_commit -p $i_commit $untracked_commit_option) ||
+	die "$(gettext "Cannot record working tree state")"
+}
+
+store_stash () {
+	while test $# != 0
+	do
+		case "$1" in
+		-m|--message)
+			shift
+			stash_msg="$1"
+			;;
+		-m*)
+			stash_msg=${1#-m}
+			;;
+		--message=*)
+			stash_msg=${1#--message=}
+			;;
+		-q|--quiet)
+			quiet=t
+			;;
+		*)
+			break
+			;;
+		esac
+		shift
+	done
+	test $# = 1 ||
+	die "$(eval_gettext "\"$dashless store\" requires one <commit> argument")"
+
+	w_commit="$1"
+	if test -z "$stash_msg"
+	then
+		stash_msg="Created via \"git stash store\"."
+	fi
+
+	git update-ref --create-reflog -m "$stash_msg" $ref_stash $w_commit
+	ret=$?
+	test $ret != 0 && test -z "$quiet" &&
+	die "$(eval_gettext "Cannot update \$ref_stash with \$w_commit")"
+	return $ret
+}
+
+push_stash () {
+	keep_index=
+	patch_mode=
+	untracked=
+	stash_msg=
+	while test $# != 0
+	do
+		case "$1" in
+		-k|--keep-index)
+			keep_index=t
+			;;
+		--no-keep-index)
+			keep_index=n
+			;;
+		-p|--patch)
+			patch_mode=t
+			# only default to keep if we don't already have an override
+			test -z "$keep_index" && keep_index=t
+			;;
+		-q|--quiet)
+			GIT_QUIET=t
+			;;
+		-u|--include-untracked)
+			untracked=untracked
+			;;
+		-a|--all)
+			untracked=all
+			;;
+		-m|--message)
+			shift
+			test -z ${1+x} && usage
+			stash_msg=$1
+			;;
+		-m*)
+			stash_msg=${1#-m}
+			;;
+		--message=*)
+			stash_msg=${1#--message=}
+			;;
+		--help)
+			show_help
+			;;
+		--)
+			shift
+			break
+			;;
+		-*)
+			option="$1"
+			eval_gettextln "error: unknown option for 'stash push': \$option"
+			usage
+			;;
+		*)
+			break
+			;;
+		esac
+		shift
+	done
+
+	eval "set $(git rev-parse --sq --prefix "$prefix" -- "$@")"
+
+	if test -n "$patch_mode" && test -n "$untracked"
+	then
+		die "$(gettext "Can't use --patch and --include-untracked or --all at the same time")"
+	fi
+
+	test -n "$untracked" || git ls-files --error-unmatch -- "$@" >/dev/null || exit 1
+
+	git update-index -q --refresh
+	if maybe_quiet no_changes "$@"
+	then
+		say "$(gettext "No local changes to save")"
+		exit 0
+	fi
+
+	git reflog exists $ref_stash ||
+		clear_stash || die "$(gettext "Cannot initialize stash")"
+
+	create_stash -m "$stash_msg" -u "$untracked" -- "$@"
+	store_stash -m "$stash_msg" -q $w_commit ||
+	die "$(gettext "Cannot save the current status")"
+	say "$(eval_gettext "Saved working directory and index state \$stash_msg")"
+
+	if test -z "$patch_mode"
+	then
+		test "$untracked" = "all" && CLEAN_X_OPTION=-x || CLEAN_X_OPTION=
+		if test -n "$untracked" && test $# = 0
+		then
+			git clean --force --quiet -d $CLEAN_X_OPTION
+		fi
+
+		if test $# != 0
+		then
+			test -z "$untracked" && UPDATE_OPTION="-u" || UPDATE_OPTION=
+			test "$untracked" = "all" && FORCE_OPTION="--force" || FORCE_OPTION=
+			git add $UPDATE_OPTION $FORCE_OPTION -- "$@"
+			git diff-index -p --cached --binary HEAD -- "$@" |
+			git apply --index -R
+		else
+			git reset --hard -q
+		fi
+
+		if test "$keep_index" = "t" && test -n "$i_tree"
+		then
+			git read-tree --reset $i_tree
+			git ls-files -z --modified -- "$@" |
+			git checkout-index -z --force --stdin
+		fi
+	else
+		git apply -R < "$TMP-patch" ||
+		die "$(gettext "Cannot remove worktree changes")"
+
+		if test "$keep_index" != "t"
+		then
+			git reset -q -- "$@"
+		fi
+	fi
+}
+
+save_stash () {
+	push_options=
+	while test $# != 0
+	do
+		case "$1" in
+		-q|--quiet)
+			GIT_QUIET=t
+			;;
+		--)
+			shift
+			break
+			;;
+		-*)
+			# pass all options through to push_stash
+			push_options="$push_options $1"
+			;;
+		*)
+			break
+			;;
+		esac
+		shift
+	done
+
+	stash_msg="$*"
+
+	if test -z "$stash_msg"
+	then
+		push_stash $push_options
+	else
+		push_stash $push_options -m "$stash_msg"
+	fi
+}
+
+have_stash () {
+	git rev-parse --verify --quiet $ref_stash >/dev/null
+}
+
+list_stash () {
+	have_stash || return 0
+	git log --format="%gd: %gs" -g --first-parent -m "$@" $ref_stash --
+}
+
+show_stash () {
+	ALLOW_UNKNOWN_FLAGS=t
+	assert_stash_like "$@"
+
+	if test -z "$FLAGS"
+	then
+		if test "$(git config --bool stash.showStat || echo true)" = "true"
+		then
+			FLAGS=--stat
+		fi
+
+		if test "$(git config --bool stash.showPatch || echo false)" = "true"
+		then
+			FLAGS=${FLAGS}${FLAGS:+ }-p
+		fi
+
+		if test -z "$FLAGS"
+		then
+			return 0
+		fi
+	fi
+
+	git diff ${FLAGS} $b_commit $w_commit
+}
+
+show_help () {
+	exec git help stash
+	exit 1
+}
+
+#
+# Parses the remaining options looking for flags and
+# at most one revision defaulting to ${ref_stash}@{0}
+# if none found.
+#
+# Derives related tree and commit objects from the
+# revision, if one is found.
+#
+# stash records the work tree, and is a merge between the
+# base commit (first parent) and the index tree (second parent).
+#
+#   REV is set to the symbolic version of the specified stash-like commit
+#   IS_STASH_LIKE is non-blank if ${REV} looks like a stash
+#   IS_STASH_REF is non-blank if the ${REV} looks like a stash ref
+#   s is set to the SHA1 of the stash commit
+#   w_commit is set to the commit containing the working tree
+#   b_commit is set to the base commit
+#   i_commit is set to the commit containing the index tree
+#   u_commit is set to the commit containing the untracked files tree
+#   w_tree is set to the working tree
+#   b_tree is set to the base tree
+#   i_tree is set to the index tree
+#   u_tree is set to the untracked files tree
+#
+#   GIT_QUIET is set to t if -q is specified
+#   INDEX_OPTION is set to --index if --index is specified.
+#   FLAGS is set to the remaining flags (if allowed)
+#
+# dies if:
+#   * too many revisions specified
+#   * no revision is specified and there is no stash stack
+#   * a revision is specified which cannot be resolve to a SHA1
+#   * a non-existent stash reference is specified
+#   * unknown flags were set and ALLOW_UNKNOWN_FLAGS is not "t"
+#
+
+parse_flags_and_rev()
+{
+	test "$PARSE_CACHE" = "$*" && return 0 # optimisation
+	PARSE_CACHE="$*"
+
+	IS_STASH_LIKE=
+	IS_STASH_REF=
+	INDEX_OPTION=
+	s=
+	w_commit=
+	b_commit=
+	i_commit=
+	u_commit=
+	w_tree=
+	b_tree=
+	i_tree=
+	u_tree=
+
+	FLAGS=
+	REV=
+	for opt
+	do
+		case "$opt" in
+			-q|--quiet)
+				GIT_QUIET=-t
+			;;
+			--index)
+				INDEX_OPTION=--index
+			;;
+			--help)
+				show_help
+			;;
+			-*)
+				test "$ALLOW_UNKNOWN_FLAGS" = t ||
+					die "$(eval_gettext "unknown option: \$opt")"
+				FLAGS="${FLAGS}${FLAGS:+ }$opt"
+			;;
+			*)
+				REV="${REV}${REV:+ }'$opt'"
+			;;
+		esac
+	done
+
+	eval set -- $REV
+
+	case $# in
+		0)
+			have_stash || die "$(gettext "No stash entries found.")"
+			set -- ${ref_stash}@{0}
+		;;
+		1)
+			:
+		;;
+		*)
+			die "$(eval_gettext "Too many revisions specified: \$REV")"
+		;;
+	esac
+
+	case "$1" in
+		*[!0-9]*)
+			:
+		;;
+		*)
+			set -- "${ref_stash}@{$1}"
+		;;
+	esac
+
+	REV=$(git rev-parse --symbolic --verify --quiet "$1") || {
+		reference="$1"
+		die "$(eval_gettext "\$reference is not a valid reference")"
+	}
+
+	i_commit=$(git rev-parse --verify --quiet "$REV^2") &&
+	set -- $(git rev-parse "$REV" "$REV^1" "$REV:" "$REV^1:" "$REV^2:" 2>/dev/null) &&
+	s=$1 &&
+	w_commit=$1 &&
+	b_commit=$2 &&
+	w_tree=$3 &&
+	b_tree=$4 &&
+	i_tree=$5 &&
+	IS_STASH_LIKE=t &&
+	test "$ref_stash" = "$(git rev-parse --symbolic-full-name "${REV%@*}")" &&
+	IS_STASH_REF=t
+
+	u_commit=$(git rev-parse --verify --quiet "$REV^3") &&
+	u_tree=$(git rev-parse "$REV^3:" 2>/dev/null)
+}
+
+is_stash_like()
+{
+	parse_flags_and_rev "$@"
+	test -n "$IS_STASH_LIKE"
+}
+
+assert_stash_like() {
+	is_stash_like "$@" || {
+		args="$*"
+		die "$(eval_gettext "'\$args' is not a stash-like commit")"
+	}
+}
+
+is_stash_ref() {
+	is_stash_like "$@" && test -n "$IS_STASH_REF"
+}
+
+assert_stash_ref() {
+	is_stash_ref "$@" || {
+		args="$*"
+		die "$(eval_gettext "'\$args' is not a stash reference")"
+	}
+}
+
+apply_stash () {
+
+	assert_stash_like "$@"
+
+	git update-index -q --refresh || die "$(gettext "unable to refresh index")"
+
+	# current index state
+	c_tree=$(git write-tree) ||
+		die "$(gettext "Cannot apply a stash in the middle of a merge")"
+
+	unstashed_index_tree=
+	if test -n "$INDEX_OPTION" && test "$b_tree" != "$i_tree" &&
+			test "$c_tree" != "$i_tree"
+	then
+		git diff-tree --binary $s^2^..$s^2 | git apply --cached
+		test $? -ne 0 &&
+			die "$(gettext "Conflicts in index. Try without --index.")"
+		unstashed_index_tree=$(git write-tree) ||
+			die "$(gettext "Could not save index tree")"
+		git reset
+	fi
+
+	if test -n "$u_tree"
+	then
+		GIT_INDEX_FILE="$TMPindex" git read-tree "$u_tree" &&
+		GIT_INDEX_FILE="$TMPindex" git checkout-index --all &&
+		rm -f "$TMPindex" ||
+		die "$(gettext "Could not restore untracked files from stash entry")"
+	fi
+
+	eval "
+		GITHEAD_$w_tree='Stashed changes' &&
+		GITHEAD_$c_tree='Updated upstream' &&
+		GITHEAD_$b_tree='Version stash was based on' &&
+		export GITHEAD_$w_tree GITHEAD_$c_tree GITHEAD_$b_tree
+	"
+
+	if test -n "$GIT_QUIET"
+	then
+		GIT_MERGE_VERBOSITY=0 && export GIT_MERGE_VERBOSITY
+	fi
+	if git merge-recursive $b_tree -- $c_tree $w_tree
+	then
+		# No conflict
+		if test -n "$unstashed_index_tree"
+		then
+			git read-tree "$unstashed_index_tree"
+		else
+			a="$TMP-added" &&
+			git diff-index --cached --name-only --diff-filter=A $c_tree >"$a" &&
+			git read-tree --reset $c_tree &&
+			git update-index --add --stdin <"$a" ||
+				die "$(gettext "Cannot unstage modified files")"
+			rm -f "$a"
+		fi
+		squelch=
+		if test -n "$GIT_QUIET"
+		then
+			squelch='>/dev/null 2>&1'
+		fi
+		(cd "$START_DIR" && eval "git status $squelch") || :
+	else
+		# Merge conflict; keep the exit status from merge-recursive
+		status=$?
+		git rerere
+		if test -n "$INDEX_OPTION"
+		then
+			gettextln "Index was not unstashed." >&2
+		fi
+		exit $status
+	fi
+}
+
+pop_stash() {
+	assert_stash_ref "$@"
+
+	if apply_stash "$@"
+	then
+		drop_stash "$@"
+	else
+		status=$?
+		say "$(gettext "The stash entry is kept in case you need it again.")"
+		exit $status
+	fi
+}
+
+drop_stash () {
+	assert_stash_ref "$@"
+
+	git reflog delete --updateref --rewrite "${REV}" &&
+		say "$(eval_gettext "Dropped \${REV} (\$s)")" ||
+		die "$(eval_gettext "\${REV}: Could not drop stash entry")"
+
+	# clear_stash if we just dropped the last stash entry
+	git rev-parse --verify --quiet "$ref_stash@{0}" >/dev/null ||
+	clear_stash
+}
+
+apply_to_branch () {
+	test -n "$1" || die "$(gettext "No branch name specified")"
+	branch=$1
+	shift 1
+
+	set -- --index "$@"
+	assert_stash_like "$@"
+
+	git checkout -b $branch $REV^ &&
+	apply_stash "$@" && {
+		test -z "$IS_STASH_REF" || drop_stash "$@"
+	}
+}
+
+test "$1" = "-p" && set "push" "$@"
+
+PARSE_CACHE='--not-parsed'
+# The default command is "push" if nothing but options are given
+seen_non_option=
+for opt
+do
+	case "$opt" in
+	--) break ;;
+	-*) ;;
+	*) seen_non_option=t; break ;;
+	esac
+done
+
+test -n "$seen_non_option" || set "push" "$@"
+
+# Main command set
+case "$1" in
+list)
+	shift
+	list_stash "$@"
+	;;
+show)
+	shift
+	show_stash "$@"
+	;;
+save)
+	shift
+	save_stash "$@"
+	;;
+push)
+	shift
+	push_stash "$@"
+	;;
+apply)
+	shift
+	apply_stash "$@"
+	;;
+clear)
+	shift
+	clear_stash "$@"
+	;;
+create)
+	shift
+	create_stash -m "$*" && echo "$w_commit"
+	;;
+store)
+	shift
+	store_stash "$@"
+	;;
+drop)
+	shift
+	drop_stash "$@"
+	;;
+pop)
+	shift
+	pop_stash "$@"
+	;;
+branch)
+	shift
+	apply_to_branch "$@"
+	;;
+*)
+	case $# in
+	0)
+		push_stash &&
+		say "$(gettext "(To restore them type \"git stash apply\")")"
+		;;
+	*)
+		usage
+	esac
+	;;
+esac