The default pet name value is an empty string.

Contributed by G-hamsteR.

L2J_Mobius_Essence_7.1_Assassin/java/org/l2jmobius/gameserver/network/clientpackets/pet/RequestChangePetName.java

@@ -58,7 +58,7 @@ public class RequestChangePetName implements ClientPacket
 			return;
 		}
 		
-		if (pet.getName() != null)
+		if ((pet.getName() != null) && !pet.getName().equals(""))
 		{
 			player.sendPacket(SystemMessageId.YOU_CANNOT_SET_THE_NAME_OF_THE_PET);
 			return;