On 28 Jul 2014, at 4:57 PM, Peter Geoghegan wrote:
> [....] Then
> again, who knows? The Mac OS X behavior seems totally arbitrary to me.
> If I had to guess I'd say it has something to do with their providing
> an open standard shim to a UTF-16 based proprietary API.
A quick glance at OSX's strxfrm() suggests they're using an implementation of strxfrm() from FreeBSD. You can find the source here:
http://www.opensource.apple.com/source/Libc/Libc-997.90.3/string/FreeBSD/strxfrm.c
(and a really quick glance at the contents of libc on OSX 10.9 reinforces this--- I don't see any calls into their CoreFoundation unicode string APIs.)