test for syntax errors

.githooks/post-checkout

@@ -29,15 +29,14 @@ 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
-                if [ -z "$opkg_c" ]; then
-                    continue
-                fi
-                next_line=$(grep -E "^\s*[#]+.*$" <<< "$opkg_c")
-                if ! [ -z "$next_line" ]; then
-                    continue
-                fi
+                # check for empty lines
+                if [ -n "$opkg_c" ]; then
+                    # check if line is not starting with '#'
+                    if ! grep -qE "^\s*[#]+.*$" <<< "$opkg_c"; then
                         echo -n "EXECUTE, $opkg_c, $now, N/A" | tr -d '\n\r' >> $GIT_UPDATE_LOG 2>&1
                         echo "" >> $GIT_UPDATE_LOG 2>&1
+                    fi
+                fi
             done
         fi
     else