Does this affect more than just the admin console? I'm sending this packet to Openfire (3.6.4):
<message to="firstname.lastname@example.org" type="groupchat" id="m_35"><subject /></message>
And Openfire isn't setting the welcome message to be blank.
Just checked, line 272 of LocalMucUser:
if (packet.getSubject() != null && packet.getSubject().trim().length() > 0
Is there a reason to deliberately ignore requests to set the room welcome message to be empty?