Merge r383339 from trunk:

* Crosscheck the length of the body chunk with the length of the ajp message
  to prevent readings beyond the buffer boundaries which possibly could reveal
  sensitive memory contents to the client.

Submitted by: rpluem
Reviewed by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@390181 13f79535-47bb-0310-9956-ffa450edef68