Add a cpio emulation script based on GNU tar.

Makefile

@@ -177,7 +177,8 @@ SCRIPT_SH = \
 	git-applymbox.sh git-applypatch.sh git-am.sh \
 	git-merge.sh git-merge-stupid.sh git-merge-octopus.sh \
 	git-merge-resolve.sh git-merge-ours.sh \
-	git-lost-found.sh git-quiltimport.sh
+	git-lost-found.sh git-quiltimport.sh \
+	cpio.sh
 
 SCRIPT_PERL = \
 	git-add--interactive.perl \

cpio.sh

@@ -0,0 +1,45 @@
+#!/bin/sh
+#
+# Emulates some cpio behavior using GNU tar
+
+die() {
+	echo >&2 "$@"
+	exit 1
+}
+
+tr0=cat
+
+while test $# -gt 0; do
+	case "$1" in
+	-0)	tr0="tr '\0' ' '";;
+	-o)	mode=o;;
+	-iuv)	;;
+	-pumd|-pumdl)
+		mode=p
+		dir="$2"
+		shift
+		;;
+	*)	die "cpio emulation supports only -0, -o, -iuv, -pumdl";;
+	esac
+	shift
+done
+
+case $mode in
+o)
+	files=.cpiofiles$$
+	$tr0 > $files
+	tar --create --file=- --files-from=$files --exclude=$files
+	rc=$?
+	rm -f $files
+	exit $rc
+	;;
+p)
+	files=.cpiofiles$$
+	$tr0 > $files
+	tar --create --file=- --files-from=$files --exclude=$files |
+	tar --extract --directory="$dir" --file=-
+	rm -f $files
+	;;
+*)
+	tar xvf - || exit
+esac