B<SSL_ERROR_WANT_READ> or B<SSL_ERROR_WANT_WRITE>, it must be repeated
with the same arguments.
+When calling SSL_write() with num=0 bytes to be sent the behaviour is
+undefined.
+
=head1 RETURN VALUES
The following return values can occur:
=item 0
-The write operation was not successful, because the write side of the
-SSL connection was shut down (the SSL_SENT_SHUTDOWN flag in the shutdown
-state is set) by calling L<SSL_shutdown(3)|SSL_shutdown(3)> or
-L<SSL_set_shutdown(3)|SSL_set_shutdown(3)>. It is also possible, that the
-underlying connection was closed.
-Call SSL_get_error() with the return value B<ret> to find out,
+The write operation was not successful. Probably the underlying connection
+was closed. Call SSL_get_error() with the return value B<ret> to find out,
whether an error occurred or the connection was shut down cleanly
(SSL_ERROR_ZERO_RETURN).