test for syntax errors

.githooks/post-checkout

@@ -29,8 +29,13 @@ if [ -f $CHECKOUT_HISTORY_FILE ]; then
         if grep -q . "${OPKG_COMMANDS_FILE}"; then
             readarray opkg_commands < <(cat $OPKG_COMMANDS_FILE)
             for opkg_c in "${opkg_commands[@]}"; do
-                test -z $opkg_c && continue;
-                test ! -z $(grep -E "^\s*[#]+.*$" <<< $opkg_c) && continue
+                if [ -z "$opkg_c" ]; then
+                    continue
+                fi
+                next_line=$(grep -E "^\s*[#]+.*$" <<< "$opkg_c")
+                if ! [ -z "$next_line" ]; then
+                    continue
+                fi
                 echo -n "EXECUTE, $opkg_c, $now, N/A" | tr -d '\n\r' >> $GIT_UPDATE_LOG 2>&1
                 echo "" >> $GIT_UPDATE_LOG 2>&1
             done