Fix crashes/issues with non-broadcast network chat.

src/network/network_chat_gui.cpp

@@ -272,6 +272,7 @@ void NetworkDrawChatMessage()
 static void SendChat(const char *buf, DestType type, int dest)
 {
 	if (StrEmpty(buf)) return;
+	assert(type >= DESTTYPE_BROADCAST && type <= DESTTYPE_CLIENT);
 	if (!_network_server) {
 		MyClient::SendChat((NetworkAction)(NETWORK_ACTION_CHAT + type), type, dest, buf, NetworkTextMessageData());
 	} else {
@@ -303,7 +304,8 @@ struct NetworkChatWindow : public Window {
 		static const StringID chat_captions[] = {
 			STR_NETWORK_CHAT_ALL_CAPTION,
 			STR_NETWORK_CHAT_COMPANY_CAPTION,
-			STR_NETWORK_CHAT_CLIENT_CAPTION
+			STR_NETWORK_CHAT_CLIENT_CAPTION,
+			STR_NULL,
 		};
 		assert((uint)this->dtype < lengthof(chat_captions));
 		this->dest_string = chat_captions[this->dtype];

src/network/network_type.h

@@ -81,9 +81,9 @@ enum NetworkPasswordType {
 /** Destination of our chat messages. */
 enum DestType {
 	DESTTYPE_BROADCAST, ///< Send message/notice to all clients (All)
-	DESTTYPE_BROADCAST_SS, ///< Send message/notice to all clients (All), but tag the broadcast to self as a self-send
 	DESTTYPE_TEAM,      ///< Send message/notice to everyone playing the same company (Team)
 	DESTTYPE_CLIENT,    ///< Send message/notice to only a certain client (Private)
+	DESTTYPE_BROADCAST_SS, ///< Send message/notice to all clients (All), but tag the broadcast to self as a self-send
 };
 
 /** Actions that can be used for NetworkTextMessage */