[XeTeX] bug in polyglossia/sanskrit? (problem with diacritical marks)

[Zdenek Wagner]

čt 16. 5. 2019 v 14:30 odesílatel Jonathan Kew <jfkthame at gmail.com> napsal:
>
> On 16/05/2019 12:31, Ulrike Fischer wrote:
> > Am Mon, 13 May 2019 17:52:17 +0200 schrieb François Patte:
> >
> >> I have just made a fresh install of texlive 2019 and encountered a
> >> problem with the diacritical marks of romanized sanskrit.
> >
>
> Do the 'dev2' script tables in FreeSerif include positioning features
> for the various combining diacritics on Latin characters? I'm guessing
> not, in which case it's unsurprising that the results will be poor if
> you present it with accented Latin, yet request Devanagari shaping behavior.
>
> I'd expect romanized Sanskrit should be typeset with script=latn, or
> with no explicit script specification.
>
I am not sure what exactly polyglossia does. It is necessary to use
romanized transliteration but load Sanskrit hyphenation patterns.


Zdeněk Wagner
http://ttsm.icpf.cas.cz/team/wagner.shtml
http://icebearsoft.euweb.cz

> JK
>
> > (copied from f.c.t.t):
> >
> > One can see it with plain xetex too, and it is not the font (I'm
> > forcing it to 2018), et it is not xdvipdfmx (it happens with tl19
> > and tl18 version). So it is quite probably an xetex engine bug.
> >
> > A plain xetex example:
> >
> > \XeTeXtracingfonts=1
> > \font\test="[C:/texlive/2018/texmf-dist/fonts/opentype/public/gnu-freefont/FreeSerif.otf]/OT:script=dev2;"
> > \test  ā ī ū ṛ ṝ ḷ ḹ ṭ ḍ ṅ ś ṣ ḥ
> > \bye
> >
> >
> > Comparing the versions gives
> > 2019:
> > Compiled with ICU version 63.1; using 63.1
> > Compiled with zlib version 1.2.11; using 1.2.11
> > Compiled with FreeType2 version 2.9.1; using 2.9.1
> > Compiled with Graphite2 version 1.3.13; using 1.3.13
> > Compiled with HarfBuzz version 2.3.1; using 2.3.1
> > Compiled with libpng version 1.6.36; using 1.6.36
> > Compiled with poppler version 0.68.0
> > Compiled with fontconfig version 2.13.1; using 2.13.1
> >
> > 2018:
> > Compiled with ICU version 61.1; using 61.1
> > Compiled with zlib version 1.2.11; using 1.2.11
> > Compiled with FreeType2 version 2.9.1; using 2.9.1
> > Compiled with Graphite2 version 1.3.11; using 1.3.11
> > Compiled with HarfBuzz version 1.7.6; using 1.7.6
> > Compiled with libpng version 1.6.34; using 1.6.34
> > Compiled with poppler version 0.64.0
> > Compiled with fontconfig version 2.13.0; using 2.13.0
> >
> > The first suspect is HarfBuzz.
> >
> >
> >
> >
>