[1514] If the new serial number is greater or equal to the old one, the SOA in

zone should be replaced by the new one. If not, the serial number in SOA will be
increased automatically

src/lib/python/isc/ddns/session.py

@@ -729,16 +729,12 @@ class UpdateSession:
                                                 ZoneFinder.NO_WILDCARD |
                                                 ZoneFinder.FIND_GLUE_OK)
         serial_operation = DDNS_SOA()
-        if self.__added_soa is not None:
-            # serial check goes here
-            if serial_operation.soa_update_check(old_soa, self.__added_soa):
+        if self.__added_soa is not None and\
+        serial_operation.soa_update_check(old_soa, self.__added_soa):
                 new_soa = self.__added_soa
-            else:
-                pass
         else:
-            new_soa = old_soa
             # increment goes here
-            new_soa = serial_operation.update_soa(new_soa)
+            new_soa = serial_operation.update_soa(old_soa)
 
         diff.delete_data(old_soa)
         diff.add_data(new_soa)