Add "git rebase --show-current-patch"

index 6da9296bf8..0b29e48221 100644
@@ -253,7 +253,7 @@ leave out at most one of A and B, in which case it defaults to HEAD.
 --show-current-patch::
 	Show the current patch in an interactive rebase or when rebase
 	is stopped because of conflicts. This is the equivalent of
-	`git show ORIG_COMMIT`.
+	`git show REBASE_HEAD`.
 
 -m::
 --merge::

index deea688e0e..8777805c9f 100644
@@ -439,7 +439,7 @@ __git_refs ()
 			track=""
 			;;
 		*)
-			for i in HEAD FETCH_HEAD ORIG_HEAD MERGE_HEAD ORIG_COMMIT; do
+			for i in HEAD FETCH_HEAD ORIG_HEAD MERGE_HEAD REBASE_HEAD; do
 				case "$i" in
 				$match*)
 					if [ -e "$dir/$i" ]; then

index ef72bd5871..a613156bcb 100644
@@ -199,14 +199,14 @@ make_patch () {
 
 die_with_patch () {
 	echo "$1" > "$state_dir"/stopped-sha
-	git update-ref ORIG_COMMIT "$1"
+	git update-ref REBASE_HEAD "$1"
 	make_patch "$1"
 	die "$2"
 }
 
 exit_with_patch () {
 	echo "$1" > "$state_dir"/stopped-sha
-	git update-ref ORIG_COMMIT "$1"
+	git update-ref REBASE_HEAD "$1"
 	make_patch $1
 	git rev-parse --verify HEAD > "$amend"
 	gpg_sign_opt_quoted=${gpg_sign_opt:+$(git rev-parse --sq-quote "$gpg_sign_opt")}

@@ -843,7 +843,7 @@ To continue rebase after editing, run:
 	exit
 	;;
 show-current-patch)
-	exec git show ORIG_COMMIT --
+	exec git show REBASE_HEAD --
 	;;
 esac
 

@@ -860,7 +860,7 @@ fi
 
 orig_head=$(git rev-parse --verify HEAD) || die "$(gettext "No HEAD?")"
 mkdir -p "$state_dir" || die "$(eval_gettext "Could not create temporary \$state_dir")"
-rm -f "$(git rev-parse --git-path ORIG_COMMIT)"
+rm -f "$(git rev-parse --git-path REBASE_HEAD)"
 
 : > "$state_dir"/interactive || die "$(gettext "Could not mark as interactive")"
 write_basic_state

index 70966c32c3..957688f236 100644
@@ -57,7 +57,7 @@ call_merge () {
 	echo "$msgnum" >"$state_dir/msgnum"
 	cmt="$(cat "$state_dir/cmt.$msgnum")"
 	echo "$cmt" > "$state_dir/current"
-	git update-ref ORIG_COMMIT "$cmt"
+	git update-ref REBASE_HEAD "$cmt"
 	hd=$(git rev-parse --verify HEAD)
 	cmt_name=$(git symbolic-ref HEAD 2> /dev/null || echo HEAD)
 	eval GITHEAD_$cmt='"${cmt_name##refs/heads/}~$(($end - $msgnum))"'

@@ -139,14 +139,14 @@ skip)
 	return
 	;;
 show-current-patch)
-	exec git show ORIG_COMMIT --
+	exec git show REBASE_HEAD --
 	;;
 esac
 
 mkdir -p "$state_dir"
 echo "$onto_name" > "$state_dir/onto_name"
 write_basic_state
-rm -f "$(git rev-parse --git-path ORIG_COMMIT)"
+rm -f "$(git rev-parse --git-path REBASE_HEAD)"
 
 msgnum=0
 for cmt in $(git rev-list --reverse --no-merges "$revisions")

index 1db4301b90..a13a581fe6 100755
@@ -182,7 +182,7 @@ You can run "git stash pop" or "git stash drop" at any time.
 }
 
 finish_rebase () {
-	rm -f "$(git rev-parse --git-path ORIG_COMMIT)"
+	rm -f "$(git rev-parse --git-path REBASE_HEAD)"
 	apply_autostash &&
 	{ git gc --auto || true; } &&
 	rm -rf "$state_dir"

index 2be4abcb7b..72d9564747 100755
@@ -306,8 +306,8 @@ test_expect_success 'rebase--merge.sh and --show-current-patch' '
 		test_must_fail git rebase --merge --onto init HEAD^ &&
 		git rebase --show-current-patch >actual.patch &&
 		GIT_TRACE=1 git rebase --show-current-patch >/dev/null 2>stderr &&
-		grep "show.*ORIG_COMMIT" stderr &&
-		test "$(git rev-parse ORIG_COMMIT)" = "$(git rev-parse two)"
+		grep "show.*REBASE_HEAD" stderr &&
+		test "$(git rev-parse REBASE_HEAD)" = "$(git rev-parse two)"
 	)
 '
 

index c0fe0193bb..23a54a4c49 100755
@@ -227,10 +227,10 @@ test_expect_success 'stop on conflicting pick' '
 
 test_expect_success 'show conflicted patch' '
 	GIT_TRACE=1 git rebase --show-current-patch >/dev/null 2>stderr &&
-	grep "show.*ORIG_COMMIT" stderr &&
+	grep "show.*REBASE_HEAD" stderr &&
 	# the original stopped-sha1 is abbreviated
 	stopped_sha1="$(git rev-parse $(cat ".git/rebase-merge/stopped-sha"))" &&
-	test "$(git rev-parse ORIG_COMMIT)" = "$stopped_sha1"
+	test "$(git rev-parse REBASE_HEAD)" = "$stopped_sha1"
 '
 
 test_expect_success 'abort' '