[PATCH] making ngx_http_upstream_test_connect catch "connection refused" with kqueue

[Ruslan Ermilov]

On Mon, Nov 05, 2012 at 10:18:28PM -0800, agentzh wrote:
> Hello!
> 
> smallfish and I both ran into a small issue with the
> ngx_http_upstream_test_connect which does not catch errors like
> "Connection refused" when kqueue is used.
> 
> The current logic only checks c->write->pending_eof but this error
> actually produced a read event on (at least) both Mac OS X and
> FreeBSD.
> 
> I've attached a simple patch (for nginx 1.2.4) to fix this by checking
> both the read and write events.
> 
> To reproduce the issue, please consider the following Nginx
> configuration snippet (assuming nothing is listening on the local port
> 1234):
> 
>     location = /t {
>         proxy_pass http://127.0.0.1:1234/;
>     }
> 
> Accessing /t gives the following message in error.log:
> 
>     [error] 28474#0: *1 kevent() reported about an closed connection
> (61: Connection refused) while reading response header from upstream
> 
> We can see that ngx_http_upstream missed it in
> ngx_http_upstream_test_connect but caught it when reading the
> (upstream) response header.
> 
> After applying my patch, Nginx can now catch it in the context of connecting:
> 
>     [error] 34067#0: *1 kevent() reported that connect() failed (61:
> Connection refused) while connecting to upstream
> 
> Best regards,
> -agentzh

Your patch looks good.