illumos gate

From FreeBSD's PR153502:

I'm seeing odd behavior from programs using regex(3) like less(1), vi(1) and sed(1) when using LANG=en_US.UTF-8 and UTF-8 inputs.

Sometimes it seems to work right:

$ echo 'é' | sed -ne '/^.$/p'
é
$ echo 'éé' | sed -ne '/^..$/p'
éé
$ echo 'aéa' | sed -ne '/a.a/p'
aéa
$ echo 'aéa' | sed -ne '/a.*a/p'
aéa
$ echo 'aaéaa' | sed -ne '/aa.aa/p'
aaéaa
$ echo 'aéaéa' | sed -ne '/a.a.a/p'
aéaéa

But not always:

$ echo 'éa' | sed -ne '/.a/p'
$ echo 'aéaa' | sed -ne '/a.aa/p'
$ echo 'éaé' | sed -ne '/.a./p'

Seems like using ".*", ".+", ".{0,}" or ".{1,}" works right, but ".{0,1}", ".{1,1}" or a lone "." doesn't always.