Merge r1233882 from trunk:

* server/core_filters.c (ap_core_input_filter): Only treat EAGAIN as
  success if a non-blocking read was requested; for a blocking read,
  it is an error condition.

Submitted by: jorton
Reviewed/backported by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1239122 13f79535-47bb-0310-9956-ffa450edef68