fix regedit

apps/sdlan/src/sdlan_hostname_regedit.erl

@@ -27,6 +27,6 @@ lookup(FullHostname) when is_binary(FullHostname) ->
     end.
 
 -spec insert(FullHostname :: binary(), Ip :: integer()) -> no_return().
-insert(FullHostname, Ip) when is_integer(FullHostname) ->
+insert(FullHostname, Ip) when is_binary(FullHostname), is_integer(Ip) ->
     <<Ip0, Ip1, Ip2, Ip3>> = <<Ip:32>>,
     true = ets:insert(?TABLE, {FullHostname, {Ip0, Ip1, Ip2, Ip3}}).

apps/sdlan/src/sdlan_network.erl

@@ -232,8 +232,13 @@ handle_call({assign_ip_addr, ChannelPid, ClientId, Mac, NetAddr0, HostName}, _Fr
             maybe_close_channel(maps:get(Mac, UsedMap, undefined)),
 
             %% 添加域名->ip的映射关系
+            case HostName =/= <<>> of
+                true ->
                     FullHostname = <<HostName/binary, ".", Domain/binary>>,
-            sdlan_hostname_regedit:insert(FullHostname, Ip),
+                    sdlan_hostname_regedit:insert(FullHostname, Ip);
+                false ->
+                    ok
+            end,
 
             %% 建立到新的channel之间的关系
             MRef = monitor(process, ChannelPid),