xbian-storager backup: fix of error status

- see http://forum.xbian.org/thread-4120-post-37005.html
- under strange circumstances, sporadically during the error-free backup,
  however, an error occurred by mistake and the backup was deleted again
- the return values of all programs contained in the pipe are now
  determined and logged in case of error
- cosmetical: the progress output is held at 100 when this is reached
  for the first time

content/usr/local/sbin/xbian-storager

@@ -1637,29 +1637,32 @@ do_backuphome ()
 	cpb () {
 		ar=0
 		while read a; do
-			echo "$a" | grep -q ^[0-9] && { (($a > $ar)) && ar=$a; echo "$a"; }
-		done | eval "$PIPECMD"
+			echo "$a" | grep -q ^[0-9] && { (($a > $ar)) && ar=$a || ar=100; echo "$ar"; }
+		done | eval "$PIPECMD" || :
 	}
 	if [ "$opt_fstype" = btrfs ]; then
 		btrfs sub delete "${tmp_dir}/home/@ro" 2>/dev/null
 		btrfs sub snap -r "${tmp_dir}/home/@" "${tmp_dir}/home/@ro" && \
 		( btrfs send -v "${tmp_dir}/home/@ro" | pv -i 20 -n -s $(du -sxb ${tmp_dir}/home/@ro | awk '{printf "%d", $1*1.08}') | $packcmd -1 >> "$FILE") 2>&1 | cpb
-		RC=$?
+		ps=${PIPESTATUS[*]}
 		btrfs sub delete "${tmp_dir}/home/@ro" && btrfs fi sync ${tmp_dir}
 	else
 		home_ds=$(zfs list -Ho name,mountpoint | grep /home$ | awk '{print $1}')
 		zfs destroy ${home_ds}@ro 2>/dev/null
 		zfs snapshot ${home_ds}@ro && \
 		( zfs send --props ${home_ds}@ro | pv -i 20 -n -s $(zfs list -Hpo refer,compressratio ${home_ds}@ro | awk '{printf "%d", $1*$2*0.970}') | $packcmd -1 >> "$FILE") 2>&1 | cpb
-		RC=$?
+		ps=${PIPESTATUS[*]}
 		zfs destroy ${home_ds}@ro
 	fi
 	set +o pipefail
 
-	if [ "$RC" -ne 0 ]; then
-		rm -f "$FILE"
-		exit 1
-	fi
+	for RC in $ps; do
+		if [ "$RC" -ne 0 ]; then
+			print_log error "error(s) happened while copying data ($ps)"
+			rm -f "$FILE"
+			exit 1
+		fi
+	done
 
 	if [ "$(dirname "$fn")" = "/xbmc-backup" -o "$fn" = "//" ]; then
 		if [ "$fn" = "//" ]; then