Mitchell Hashimoto provided this link on a duplicate report:

> RFC2616 page 31 (http://tools.ietf.org/html/rfc2616#page-31) states that headers must be separated
> by CRLF. Specifically, the above "\n\n" for the header separator is causing issues with some
> minimal RFC-compliant web servers.

So I checked the RFC carefully again and found this:

> http://tools.ietf.org/html/rfc2616#section-3.7.1
>
> When in canonical form, media subtypes of the "text" type use CRLF as
> the text line break. HTTP relaxes this requirement and allows the
> transport of text media with plain CR or LF alone representing a line
> break when it is done consistently for an entire entity-body. HTTP
> applications MUST accept CRLF, bare CR, and bare LF as being
> representative of a line break in text media received via HTTP

The requests we send are multipart/form-data, so the RFC exception for text/* would not apply.  On one hand, I don’t think we can say that sending LF is not a bug, on the other hand, I believe nearly all HTTP servers just accept all newlines anyway.