diff --git a/telegram-purple.c b/telegram-purple.c
index b660996..01b4b2c 100755
--- a/telegram-purple.c
+++ b/telegram-purple.c
@@ -388,10 +388,21 @@ static void update_message_received (struct tgl_state *TLS, struct tgl_message *
   }
   
   if (
+      // ignore all empty or deleted messages
       (M->flags & (FLAG_MESSAGE_EMPTY | FLAG_DELETED)) ||
+     
+      // ignore all messages that are not created for the first time
      !(M->flags & FLAG_CREATED) ||
+      
+      // drop all messages that don't contain any data
       !M->message ||
+      
+      // drop messages that were created by *this* client and were already
+      // added to the conversation
       our_msg (TLS, M) ||
+      
+      // drop all messages with an invalid peer id.
+      // TODO: Verify if we actually need this
       !tgl_get_peer_type (M->to_id)
   ) {
     return;
diff --git a/tgp-structs.c b/tgp-structs.c
index ab5a2ed..df89527 100644
--- a/tgp-structs.c
+++ b/tgp-structs.c
@@ -94,12 +94,6 @@ connection_data *connection_data_init (struct tgl_state *TLS, PurpleConnection *
   return conn;
 }
 
-static void tgp_xfer_send_data_free (gpointer _data) {
-  struct tgp_xfer_send_data *data = _data;
-  if (data->timer) { purple_timeout_remove(data->timer); }
-  g_free (data);
-}
-
 void *connection_data_free (connection_data *conn) {
   if (conn->write_timer) { purple_timeout_remove (conn->write_timer); }
   if (conn->login_timer) { purple_timeout_remove (conn->login_timer); }