The behaviour is undefined when calling SSL_write() with num=0.
Submitted by:
Reviewed by:
PR: 141

doc/ssl/SSL_write.pod

diff --git a/doc/ssl/SSL_write.pod b/doc/ssl/SSL_write.pod
index dfa42e9..e013c12 100644
--- a/doc/ssl/SSL_write.pod
+++ b/doc/ssl/SSL_write.pod
@@ -65,6 +65,9 @@
 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: