IPv6 + HTTP proxy is missing [ on HTTPS URLs

[swankjesse]

Both curl and Firefox include [ and ] in the request line and host header when using IPv6 with an HTTP proxy. OkHttp doesn’t and this is broken.

CONNECT [::1]:443 HTTP/1.1
Host: [::1]:443
User-Agent: curl/7.43.0
Proxy-Connection: Keep-Alive

GET http://[::1]/foo HTTP/1.1
Host: [::1]
User-Agent: curl/7.43.0
Accept: */*
Proxy-Connection: Keep-Alive

CONNECT [::1]:443 HTTP/1.1
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:43.0) Gecko/20100101 Firefox/43.0
Proxy-Connection: keep-alive
Connection: keep-alive
Host: [::1]:443

GET http://[::1]/foo HTTP/1.1
Host: [::1]
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:43.0) Gecko/20100101 Firefox/43.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Connection: keep-alive