Fix an issue that meant that any pipe-lined data read by Tomcat before an asynchronous request completed was lost during the completion of the asynchronous request.

Fix an issue that meant that any pipe-lined data read by Tomcat before an asynchronous request completed was lost during the completion of the asynchronous request. This mean that the pipe-lined request(s) would be lost and/or corrupted.

http://svn.apache.org/r1668138