[PATCH] Core: fix content handler and location configuration mismatch.

[Maxim Dounin]

Hello!

On Thu, Dec 06, 2012 at 05:14:11PM -0800, Piotr Sikora wrote:

> Core: fix content handler and location configuration mismatch.
> 
> When using exclusive content handlers (proxy_pass, etc.) and "if"
> pseudo-locations, content handler was always set to the one from the
> last "if" pseudo-location that evaluated to true or to the one from
> the location block if "if" pseudo-locations didn't provide any.
> At the same time, location configuration was updated for each "if"
> pseudo-location that evaluated to true, which resulted in content
> handler and location configuration mismatch.
> 
> For example, following configuration would result in SIGSEGV, because
> "proxy_pass" content handler (set in the "if ($pass)" pseudo-location)
> would be called with location configuration from the "if ($slow)"
> pseudo-location which doesn't contain any upstream configuration.
> 
>     location / {
>         set $pass  1;
>         set $slow  1;
> 
>         if ($pass) {
>             proxy_pass  http://127.0.0.1:8000;
>         }
> 
>         if ($slow) {
>             limit_rate  10k;
>         }
>     }
> 
> This patch fixes this issue by keeping track of and restoring location
> configuration from which the content handler originated.

And what will happen with the configuration specified in the "if 
($slow) { ... }" as in the config above?

For limit_rate your config will work as it's saved in request by 
ngx_http_update_location_config(), but e.g.


    if ($slow) {
        add_header "X-Accel-Limit-Rate: 10k";
    }

will silently ignore if() match, which is wrong.

[...]

-- 
Maxim Dounin
http://nginx.com/support.html