Description of problem:

"include /etc/nginx/conf.d/*.conf;" is used to glob in configuration snippets, while listen directive is used without 'default_server' option in default.conf, making the default server matching behavior globbing order dependent. If some snippet file like 'a.conf' appears in the included directory, default server goes to 'a.conf' instead of default.conf.

The following paragraph is cited from http://wiki.nginx.org/HttpCoreModule#listen

If the directive has the default_server parameter, then the enclosing server {...} block will be the default server for the address:port pair. This is useful for name-based virtual hosting where you wish to specify the default server block for hostnames that do not match any server_name directives. If there are no directives with the default_server parameter, then the default server will be the first server block in which the address:port pair appears. 

Version-Release number of selected component (if applicable):

nginx-1.0.15-1.el6.x86_64

How reproducible:

Steps to Reproduce:

1. add some configuration snippet 'smaller' than default.conf in globbing order
# cat >/etc/nginx/conf.d/a.conf <<EOF
server {
  listen 80;
  server_name a.example.com;
  return 403;
}

2. tell nginx to reread configuration
# killall -HUP nginx

3. try http access with

HEAD / HTTP/1.0
Host: not_a.example.com

  
Actual results:

HTTP/1.1 403 Forbidden
Server: nginx/1.0.15
Date: Tue, 24 Jul 2012 13:40:25 GMT
Content-Type: text/html
Content-Length: 169
Connection: close

Expected results:

HTTP/1.1 200 OK
Server: nginx/1.0.15
Date: Tue, 24 Jul 2012 13:40:49 GMT
Content-Type: text/html
Content-Length: 3698
Last-Modified: Mon, 14 May 2012 18:28:04 GMT
Connection: close
Accept-Ranges: bytes

Additional info:

This problem could be fixed by adding 'default_server' to the 'listen' directive in default.conf.