[PATCH 1/2] stash: implement "stash create"

[Junio C Hamano <gitster@pobox.com>]

This subcommand creates a stash from the current state and writes out the
resulting commit object ID to the standard output, without updating the
stash ref nor resetting the tree.  It is intended to be used by scripts
to temporarily rewind the working tree to a clean state.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---

 * This is currently only needed for the next one, which I do
   not think is ready for 1.5.3, so both will stay in either
   'pu' or perhaps in 'next'.

 git-stash.sh |   25 +++++++++++++++++++++----
 1 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/git-stash.sh b/git-stash.sh
index de13dd1..8c22cd4 100755
--- a/git-stash.sh
+++ b/git-stash.sh
@@ -23,7 +23,7 @@ clear_stash () {
 	: >"$logfile"
 }
 
-save_stash () {
+create_stash () {
 	stash_msg="$1"
 
 	if no_changes
@@ -31,9 +31,6 @@ save_stash () {
 		echo >&2 'No local changes to save'
 		exit 0
 	fi
-	test -f "$GIT_DIR/logs/$ref_stash" ||
-		clear_stash || die "Cannot initialize stash"
-
 	# state of the base commit
 	if b_commit=$(git rev-parse --verify HEAD)
 	then
@@ -79,7 +76,20 @@ save_stash () {
 	w_commit=$(printf '%s\n' "$stash_msg" |
 		git commit-tree $w_tree -p $b_commit -p $i_commit) ||
 		die "Cannot record working tree state"
+}
+
+save_stash () {
+	stash_msg="$1"
+
+	if no_changes
+	then
+		echo >&2 'No local changes to save'
+		exit 0
+	fi
+	test -f "$GIT_DIR/logs/$ref_stash" ||
+		clear_stash || die "Cannot initialize stash"
 
+	create_stash "$stash_msg"
 	git update-ref -m "$stash_msg" $ref_stash $w_commit ||
 		die "Cannot save the current status"
 	printf >&2 'Saved "%s"\n' "$stash_msg"
@@ -185,6 +195,13 @@ apply)
 clear)
 	clear_stash
 	;;
+create)
+	if test $# -gt 0 && test "$1" = create
+	then
+		shift
+	fi
+	create_stash "$*" && echo "$w_commit"
+	;;
 help | usage)
 	usage
 	;;
-- 
1.5.3.rc0.81.g1ed84