Index: wp-includes/wp-db.php
===================================================================
--- wp-includes/wp-db.php	(revision 28871)
+++ wp-includes/wp-db.php	(working copy)
@@ -1367,6 +1367,26 @@
 				}
 			}
 
+			// call set_ssl if mysql client flag set
+			if ( $client_flags & MYSQL_CLIENT_SSL ) {
+				$pack = array( $this->dbh );
+				$call_set = false;
+				foreach( array( 'MYSQL_SSL_KEY', 'MYSQL_SSL_CERT', 'MYSQL_SSL_CA',
+						'MYSQL_SSL_CAPATH', 'MYSQL_SSL_CIPHER' ) as $opt_key ) {
+					$pack[] = ( defined( $opt_key ) ) ? constant( $opt_key ) : null;
+					$call_set |= defined( $opt_key );
+				}
+				/* Now if anything was packed - unpack into the function.
+				 * Note this doesn't check if paths exist, as per the PHP doc
+				 * at http://www.php.net/manual/en/mysqli.ssl-set.php: "This
+				 * function always returns TRUE value. If SSL setup is incorrect
+				 * mysqli_real_connect() will return an error ..."
+				 */
+				if ( $call_set ) {
+					call_user_func_array( 'mysqli_ssl_set', $pack );
+				}
+			}
+
 			if ( WP_DEBUG ) {
 				mysqli_real_connect( $this->dbh, $host, $this->dbuser, $this->dbpassword, null, $port, $socket, $client_flags );
 			} else {