Condition to match a missing "Host:" header

[Luigi Perroti]

Igor Sysoev <is at ...> writes:

>You need just:
>
>location = /400.html {
>     root /www/errors;
>     internal;
>     access_log /var/log/nginx/access.log;
>}

Unfortunately, if I do that the 400 responses that my application sends get
logged too. Which I would prefer to avoid.

>BTW, in 0.7.12 the special server_name "" will allow to handle
>requests without Host not in default listening server:
>
>     server {
>         listen 80 default;
>         server_name  _;
>     }
>
>    server {
>         listen 80;
>         server_name  www.example.com "";
>     }

Does that mean that if ($host = "") would evaluate to true if no Host: header is
sent? That would precisely be what I need.

-Luigi