Send the motd as one single big message

We append each line to a string, and when the MOTD is
complete, we send that string at once.

src/irc/irc_client.cpp

@@ -222,6 +222,27 @@ void IrcClient::on_channel_message(const IrcMessage& message)
   this->bridge->send_message(iid, nick, body, muc);
 }
 
+void IrcClient::empty_motd(const IrcMessage& message)
+{
+  (void)message;
+  this->motd.erase();
+}
+
+void IrcClient::on_motd_line(const IrcMessage& message)
+{
+  const std::string body = message.arguments[1];
+  // We could send the MOTD without a line break between each IRC-message,
+  // but sometimes it contains some ASCII art, we use line breaks to keep
+  // them intact.
+  this->motd += body+"\n";
+}
+
+void IrcClient::send_motd(const IrcMessage& message)
+{
+  (void)message;
+  this->bridge->send_xmpp_message(this->hostname, "", this->motd);
+}
+
 void IrcClient::on_topic_received(const IrcMessage& message)
 {
   const std::string chan_name = message.arguments[1];

src/irc/irc_client.hpp

@@ -99,6 +99,18 @@ public:
    * Forward the server message received from IRC to the XMPP component
    */
   void forward_server_message(const IrcMessage& message);
+  /**
+   * Just empty the motd we kept as a string
+   */
+  void empty_motd(const IrcMessage& message);
+  /**
+   * Send the MOTD string as one single "big" message
+   */
+  void send_motd(const IrcMessage& message);
+  /**
+   * Append this line to the MOTD
+   */
+  void on_motd_line(const IrcMessage& message);
   /**
    * Forward the join of an other user into an IRC channel, and save the
    * IrcUsers in the IrcChannel
@@ -172,6 +184,11 @@ private:
    */
   std::vector<std::string> channels_to_join;
   bool welcomed;
+  /**
+   * Each motd line received is appended to this string, which we send when
+   * the motd is completely received
+   */
+  std::string motd;
   IrcClient(const IrcClient&) = delete;
   IrcClient(IrcClient&&) = delete;
   IrcClient& operator=(const IrcClient&) = delete;
@@ -186,8 +203,12 @@ typedef void (IrcClient::*irc_callback_t)(const IrcMessage&);
 
 static const std::unordered_map<std::string, irc_callback_t> irc_callbacks = {
   {"NOTICE", &IrcClient::forward_server_message},
-  {"375", &IrcClient::forward_server_message},
-  {"372", &IrcClient::forward_server_message},
+  {"RPL_MOTDSTART", &IrcClient::empty_motd},
+  {"375", &IrcClient::empty_motd},
+  {"RPL_MOTD", &IrcClient::on_motd_line},
+  {"372", &IrcClient::on_motd_line},
+  {"RPL_MOTDEND", &IrcClient::send_motd},
+  {"376", &IrcClient::send_motd},
   {"JOIN", &IrcClient::on_channel_join},
   {"PRIVMSG", &IrcClient::on_channel_message},
   {"353", &IrcClient::set_and_forward_user_list},