SSL: avoid using OpenSSL config in build directory (ticket #2404). With this change, the NGX_OPENSSL_NO_CONFIG macro is defined when nginx is asked to build OpenSSL itself. And with this macro automatic loading of OpenSSL configuration (from the build directory) is prevented unless the OPENSSL_CONF environment variable is explicitly set. Note that not loading configuration is broken in OpenSSL 1.1.1 and 1.1.1a (fixed in OpenSSL 1.1.1b, see https://github.com/openssl/openssl/issues/7350). If nginx is used to compile these OpenSSL versions, configuring nginx with NGX_OPENSSL_NO_CONFIG explicitly set to 0 might be used as a workaround.

// 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;
}