Along with nginx-1.1.4, a new directive named 'proxy_http_version' introduced
I thought it was something related to the communication between nginx cache and upstream web server, right?

But per my tests with latest v-1.2.1, Nginx is still using HTTP/1.0 to access upstream web server.

+++++++++
abc $ curl -I -H 'If-None-Match: "9cx7b1-x2e-44xa4x9axd0x0"' http://test.stg/crossdomain.xml
HTTP/1.1 200 OK
Server: nginx/1.2.1
...
+++++++++ end

Which intends to return 3.4 if it's using HTTP/1.1, did I misunderstand this directive?

Thanks for any input..