Upstream: fixed X-Accel-Expires/Cache-Control/Expires handling. Previously, if caching was disabled due to Expires in the past, nginx failed to cache the response even if it was cacheable as per subsequently parsed Cache-Control header (ticket #964). Similarly, if caching was disabled due to Expires in the past, "Cache-Control: no-cache" or "Cache-Control: max-age=0", caching was not used if it was cacheable as per subsequently parsed X-Accel-Expires header. Fix is to avoid disabling caching immediately after parsing Expires in the past or Cache-Control, but rather set flags which are later checked by ngx_http_upstream_process_headers() (and cleared by "Cache-Control: max-age" and X-Accel-Expires). Additionally, now X-Accel-Expires does not prevent parsing of cache control extensions, notably stale-while-revalidate and stale-if-error. This ensures that order of the X-Accel-Expires and Cache-Control headers is not important. Prodded by Vadim Fedorenko and Yugo Horie.

// stub module to test header files' C++ compatibility

extern "C" {
  #include <ngx_config.h>
  #include <ngx_core.h>
  #include <ngx_event.h>
  #include <ngx_event_connect.h>
  #include <ngx_event_pipe.h>

  #include <ngx_http.h>

  #include <ngx_mail.h>
  #include <ngx_mail_pop3_module.h>
  #include <ngx_mail_imap_module.h>
  #include <ngx_mail_smtp_module.h>

  #include <ngx_stream.h>
}

// nginx header files should go before other, because they define 64-bit off_t
// #include <string>


void ngx_cpp_test_handler(void *data);

void
ngx_cpp_test_handler(void *data)
{
    return;
}