Verify username provided in registration web form

src/web/mod_register_web.erl

@@ -516,6 +516,12 @@ form_del_get(Host, Lang) ->
 %%                                    {error, not_allowed} |
 %%                                    {error, invalid_jid}
 register_account(Username, Host, Password) ->
+    try exmpp_jid:make(Username, Host) of
+	_ -> register_account2(Username, Host, Password)
+    catch
+	_ -> {error, invalid_jid}
+    end.
+register_account2(Username, Host, Password) ->
     case ejabberd_auth:try_register(Username, Host, Password) of
 	{atomic, Res} ->
 	    {success, Res, {Username, Host, Password}};