diff --git a/make/pkg-dist.mk b/make/pkg-dist.mk
index 879bfc54..c5dee869 100644
--- a/make/pkg-dist.mk
+++ b/make/pkg-dist.mk
@@ -25,9 +25,9 @@ RELEASES_FILE                = $(TOPDIR)/RELEASES$(FLAVOUR_SUFFIX)
 RELEASES                    ?= $(shell $(PKG_SH_EXE) version \
 	-p $(OS_NAME_VERSION)/$(PKG_ARCH) $(RELEASES_FILE) read | $(SED) 's/-dev//')
 PKG_CHECK_VCS_SYNC_BEFORE_RELEASE ?= true
-HASH                         = $(shell $(cvs_files) -z | \
+HASH                         = $(shell $(cvs_files) -s -z | \
 	grep -vz "CHANGES\|VERSION\|HASH\|MD5SUMS\|RELEASES" | \
-	xargs -0 md5sum | md5sum | $(SED) 's/ .*//')
+	md5sum | $(SED) 's/ .*//')
 LOCAL_REPO                  ?= /srv/dav/pub/local/packages/suse/$(OS_NAME_VERSION)
 
 PACKAGE_VCS_FILES           ?= false
diff --git a/scripts/pkg.sh b/scripts/pkg.sh
index 38ff7c35..31cf398d 100644
--- a/scripts/pkg.sh
+++ b/scripts/pkg.sh
@@ -107,12 +107,16 @@ scm_files()
 
 calculate_hash()
 {
-	(
+	local h
+	h=`(
+		set -o pipefail
 		cd $TOPDIR
-		scm_files -z | \
+		scm_files -s -z | \
 			grep -vz "CHANGES\|VERSION\|HASH\|MD5SUMS\|RELEASES" | \
-			xargs -0 md5sum | md5sum | sed 's/ .*//'
-	)
+			md5sum | sed 's/ .*//'
+	)` || fatal "failed to calculate source hash"
+	[ -n "$h" ] || fatal "failed to calculate source hash"
+	echo $h
 }
 
 check_scm()
@@ -180,6 +184,7 @@ check_next_version()
 		return
 	fi
 	local h=`calculate_hash`
+	[ -n "$h" ] || fatal "failed to calculate source hash"
 	if [ ! -f $TOPDIR/HASH ]; then
 		echo "+ $PKG_PROJECT has no HASH file, needs release" >&2
 		echo $v
@@ -602,6 +607,7 @@ upload_pkg()
 	local p
 	local v=`read_map $TOPDIR/VERSION | sed 's/-dev//'`
 	local h=`calculate_hash`
+	[ -n "$h" ] || fatal "failed to calculate source hash"
 	case $PKG_FORMAT in
 	rpm)
 		server=pkg.janware.com
diff --git a/scripts/scm.sh b/scripts/scm.sh
index c359b489..ca482409 100644
--- a/scripts/scm.sh
+++ b/scripts/scm.sh
@@ -150,7 +150,33 @@ cmd_ls_files()
 		list_dirents_git $1
 	}
 
-	set -- `getopt fnzta "$@"`
+	list_dirents_git_ids()
+	{
+		local entry meta mode sha
+		while IFS= read -r -d '' entry; do
+			meta=${entry%%$'\t'*}
+			mode=${meta%% *}
+			sha=${meta##* }
+			[ "$opt_no_submodules" = 1 ] && [ "$mode" = 160000 ] && continue
+			[ "$opt_only_regular_files" = 1 ] && [ "$mode" != 100644 ] && [ "$mode" != 100755 ] && continue
+			output "$sha ${entry#*$'\t'}"
+		done < <(git ls-tree -r -z HEAD "$1")
+	}
+
+	list_dirents_ids()
+	{
+		if [ -d $1/CVS ]; then
+			echo "failed to list file ids in $(realpath $1): $scm has no file ids" >&2
+			exit 1
+		fi
+		git -C $1 status >/dev/null 2>&1 || {
+			echo "failed to list file ids in $(realpath $1): no VCS" >&2
+			exit 1
+		}
+		list_dirents_git_ids $1
+	}
+
+	set -- `getopt fnzsta "$@"`
 
 	while [ "$1" != -- ]; do
 	case $1 in
@@ -160,6 +186,9 @@ cmd_ls_files()
 	-n)
 		opt_no_submodules=1
 		;;
+	-s)
+		show_ids=1
+		;;
 	-z)
 		zero_terminate=1
 		git_ls_files_opts="$git_ls_files_opts -z"
@@ -181,6 +210,8 @@ cmd_ls_files()
 
 	if [ "$text_files" ]; then
 		list_dirents . | sort $opt_sort | xargs file -N | grep ":.*text" | cut -d: -f1
+	elif [ "$show_ids" = 1 ]; then
+		list_dirents_ids . | sort $opt_sort -k2
 	else
 		list_dirents . | sort $opt_sort
 	fi