I'm not quite comfortable with this direction of supporting non-standard server responses -- especially the part where you're supporting only '\n' instead of '\r\n' in header delimiters. I can understand the change to have an empty message status, but the rest I'm not so sure.

Is there a compelling reason (aside from being more forgiving of broken servers) for this? I'm happy to merge it, but I'd just like to understand how important it is to support broken HTTP servers to allow this change in.

For example, just eBay site

$ curl -si http://www.ebay.com/electronics|sed -e "s/\r/\\\\r/g"
HTTP/1.1 301 Moved Permanently
Location: http://www.ebay.com/rpp/electronics\r
\r

The end of status message does not meet CR.
Also, there are many similar examples.

Those server responses is out of control.
Nevertheless, I think it should be parsed.

Ouch. 😢

Alright, I'm convinced. Merging now.

LGTM