call_handlers(): added clarifying comment.

src/microhttpd/daemon.c

@@ -1203,6 +1203,9 @@ call_handlers (struct MHD_Connection *con,
    * zero timeout for next select()/poll(). */
   /* Thread-per-connection do not need global zero timeout as
    * connections are processed individually. */
+  /* Note: no need to check for read buffer availability for
+   * TLS read-ready connection in 'read info' state as connection
+   * without space in read buffer will be market as 'info block'. */
   if ( (!con->daemon->data_already_pending) &&
        (0 == (con->daemon->options & MHD_USE_THREAD_PER_CONNECTION)) )
     {