[XeTeX] Alternate Ξ glyphs in GFS Neohellenic

[Joel C. Salomon]

On Tue, Sep 1, 2015 at 12:19 PM, Arthur Reutenauer
<arthur.reutenauer at normalesup.org> wrote:
<snip>
>   For some strange reason the glyph you want is not accessible through
> OpenType features, as a look into the GSUB table confirms, but is
> included as a separate character from the Private Use Area (U+E004);
> that's why copy-pasting from the PDF file works for this particular
> glyphs, as Phil showed; but it's obviously a bad idea to do so because
> you would need to input all Ξ as this PUA character, and then your PDF
> files won't be searchable.
<snip>

The http://ctan.org/pkg/accsupp package could be helpful in a
temporary work-around:

\usepackage{accsupp, newunicodechar}
\newunicodechar{Ξ}{\BeginAccSupp{unicode,ActualText=Ξ}‹PUAchar›\EndAccSupp{}}

—Joel