Net::HTTP should assume HTTP/0.9 on unexpected responses
Currently Net::HTTP.read_status_line throws Net::HTTPBadResponse if the status line does not conform to HTTP/1.1 specifications.
But in cases when the web server implements a request size limit, it may not read HTTP/1.1 trailer after the request URI and may send back an HTTP/0.9 response.
Nginx does this for 414 Request-URI Too Large responses:
Perl's Net::HTTP provides a "laxed" option to read_response_headers() to assume HTTP/0.9 if it can't find an HTTP/1.1 status line. Ruby should provide a similar option.