[HarfBuzz] Thai below-base normalization

[Richard Wordingham]

On Thu, 23 Jan 2014 11:09:07 -0600
Martin Hosken <mhosken at gmail.com> wrote:

(archived as
https://lists.freedesktop.org/archives/harfbuzz/2014-January/004060.html)

> > It's not clear to me, then, why uniscribe treats this in the way it 
> > does. (Perhaps there was no good reason, and it was merely an
> > arbitrary choice of ordering in the absence of any clear
> > requirement?)  

> In my data, I have no examples of a U+0E3A occurring after/below
> U+0E38/9. So I agree with this patch. Note that U+0E3A does occur
> following upper vowels (U+0E34-7).

A discussions of IDN root names in the Thai script has turned up a
possible example.  Did Northern Khmer use PHINTHU below SARA U as one
of its vowel symbols?  It certainly used the combination, though I
believe that this has been replaced by the more conventional
<U+0E38 THAI CHARACTER SARA U, U+0E4D THAI CHARACTER NIKHAHIT>.

Richard.