PR: 1949

Submitted by: David.Smith@cern.ch
Approved by: steve@openssl.org

When checking whether to flush the output BIO use BIO_CTRL_WPENDING instead
of BIO_CTRL_INFO. In most cases this will have no effect since the following
BIOs wont buffer. In the case of a following buffering BIO this will check
for any pending data in the whole chain and not just the single BIO.

See:
https://issues.apache.org/bugzilla/show_bug.cgi?id=46952
for a detailed analysis of this issue.

ssl/s3_srvr.c

@@ -436,7 +436,7 @@ int ssl3_accept(SSL *s)
 		
 		case SSL3_ST_SW_FLUSH:
 			/* number of bytes to be flushed */
-			num1=BIO_ctrl(s->wbio,BIO_CTRL_INFO,0,NULL);
+			num1=BIO_ctrl(s->wbio,BIO_CTRL_WPENDING,0,NULL);
 			if (num1 > 0)
 				{
 				s->rwstate=SSL_WRITING;