<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On 31 Dec 2017, at 18:07, Nathaniel Smith <<a href="mailto:njs@pobox.com" class="">njs@pobox.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="auto" class=""><div class=""><div class="gmail_extra"><div class="gmail_quote">On Dec 31, 2017 7:37 AM, "Stephen J. Turnbull" <<a href="mailto:turnbull.stephen.fw@u.tsukuba.ac.jp" class="">turnbull.stephen.fw@u.tsukuba.ac.jp</a>> wrote:<br type="attribution" class=""><blockquote class="quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div class="quoted-text">Nathaniel Smith writes:<br class="">
<br class="">
> Issue 1: Python's built-in IDNA implementation is wrong (implements<br class="">
> IDNA 2003, not IDNA 2008).<br class="">
<br class="">
</div>Is "wrong" the right word here? I'll grant you that 2008 is *better*,<br class="">
but typically in practice versions coexist for years. Ie, is there no<br class="">
backward compatibility issue with registries that specified IDNA 2003?<br class=""></blockquote></div></div></div><div dir="auto" class=""><br class=""></div><div dir="auto" class="">Well, yeah, I was simplifying, but at the least we can say that always and only using IDNA 2003 certainly isn't right :-). I think in most cases the preferred way to deal with these kinds of issues is not to carry around an IDNA 2003 implementation, but instead to use an IDNA 2008 implementation with the "transitional compatibility" flag enabled in the UTS46 preprocessor? But this is rapidly exceeding my knowledge.</div><div dir="auto" class=""><br class=""></div><div dir="auto" class="">This is another reason why we ought to let users do their own IDNA handling if they want…</div></div></div></blockquote><div><br class=""></div>Do you know what the major browser do w.r.t. IDNA support? If those unconditionally use IDNA 2008 is should be fairly safe to move to that in Python as well because that would mean we’re less likely to run into backward compatibility issues.</div><div><br class=""></div><div>Ronald</div><div><br class=""></div></body></html>