Dmitry Gutov <dgutov@yandex.ru> schrieb am Do., 1. Dez. 2016 um 01:30 Uhr:

Further, now that Emacs 25 is out, and we are allowed to have more
breaking changes in Emacs 26, I think we should change the check at the
end of url-http-create-request to just use multibyte-string-p.

I think that's a good idea. (The check should also be moved to the front and documented, but those are minor nits.)