XHR LC comment: header encoding

[Julian Reschke]

Hi,

I think XHR needs to elaborate on how non-ASCII characters in request 
headers are put on the wire, and how non-ASCII characters in response 
headers are transformed back to Javascript characters.

For request headers, I would assume that the character encoding is 
ISO-8859-1, and if a character can't be encoded using ISO-8859-1, some 
kind of error handling occurs (ignore the character/ignore the 
header/throw?).

For response headers, I'd expect that the octet sequence is decoded 
using ISO-8859-1; so no specific error handling would be needed 
(although the result may be funny when the intended encoding was 
something different).

Best regards, Julian