The default value for collation in text-sort is incorrect

[ndw]

The default value is

https://www.w3.org/2005/xpath-functions/collation/codepoint

But that is incorrect. The name of the collation is an http: URI, not an https: URI. The collation URI is correct in the prose that follows.

[ndw]

This one is kind of ugly. We have implementations and probably users who have copied and pasted this URI. So it's going to be a problem if we fix it. And it's not easy to see why https://... is wrong. You have to squint pretty hard to see the difference. On the other hand, we don't want to say it isn't an error because if users copy the URI to some other application, it will very likely raise an error there. That's also a problem.

In whatever erratum we issue to fix the error, I'm tempted to include something like the following:

Implementors are encouraged to detect URIs of the form https://www.w3.org/... in collations and automatically correct them to the http: form, with an appropriate warning to the user if possible.