Fixed parsing of absolute URIs with empty path (ticket #2079). When the request line contains request-target in the absolute-URI form, it can contain path-empty instead of a single slash (see RFC 7230, RFC 3986). Previously, the ngx_http_parse_request_line() function only accepted empty path when there was no query string. With this change, non-empty query is also correctly handled. That is, request line "GET http://example.com?foo HTTP/1.1" is accepted and results in $uri "/" and $args "foo". Note that $request_uri remains "?foo", similarly to how spaces in URIs are handled. Providing "/?foo", similarly to how "/" is provided for "GET http://example.com HTTP/1.1", requires allocation.

scgi_param  REQUEST_METHOD     $request_method;
scgi_param  REQUEST_URI        $request_uri;
scgi_param  QUERY_STRING       $query_string;
scgi_param  CONTENT_TYPE       $content_type;

scgi_param  DOCUMENT_URI       $document_uri;
scgi_param  DOCUMENT_ROOT      $document_root;
scgi_param  SCGI               1;
scgi_param  SERVER_PROTOCOL    $server_protocol;
scgi_param  REQUEST_SCHEME     $scheme;
scgi_param  HTTPS              $https if_not_empty;

scgi_param  REMOTE_ADDR        $remote_addr;
scgi_param  REMOTE_PORT        $remote_port;
scgi_param  SERVER_PORT        $server_port;
scgi_param  SERVER_NAME        $server_name;