[XeTeX] Issue with Old Italic script & fontspec

[David J. Perry]

I am working with a group of scholars to implement the Old Italic block 
of Unicode.  For this purpose I have created a font to support the 
Faliscan language.  But I am getting unexpected behavior with the 
stylistic sets.

The minimal example pasted at the end of this email gives the result 
shown in OldItalicMinimal png.  (Note: that example does compile on my 
system, but won't work without the customized font.  I will share the 
font if anyone really wants it.)  What's happening is that Stylistic Set 
1 is being applied where it should not be.  Note that in the code I used 
curly braces to limit the effect of SS1 to only a few characters, a 
procedure that normally works correctly.  Yet SS1 is affecting the line 
before it and the complete Old Italic sample alphabet below it.

There might be something wrong with the font, but if so I can't figure 
out what it is.  I carefully defined the stylistic sets as features for 
Faliscan (whose code is XFA) only, not as part of default language under 
the Old Italic script.  This is shown in the OI_FontEditor attachment.  
Everything works correctly in the font editor's preview window.

I may be calling fontspec incorrectly, there may be a problem with the 
font, or xetex may be doing something weird.  I'd appreciate any help in 
sorting this out since I just can't figure out what's the cause.

* * * * * *
% !TEX TS-program = xelatex

% !TEX encoding = UTF-8


\documentclass[12pt]{article}


\usepackage{fontspec}

\usepackage{tabto} %to get absolute positions on a line

\setmainfont{Cardo}


\begin{document}


\noindent The first two lines should show the same shapes, while the 
third line should show alternate glyphs applied via a stylistic set. 
FaliscanCDS is the font I have constructed and am testing.\\


\tabto{.5in}������������������ \tabto{1.75in}Cardo font as test for 
default shapes\\

\newfontlanguage{Faliscan}{XFA} %declare the new language

\fontspec[Script=Old Italic,Language=Faliscan]{FaliscanCDS} %set the 
font for Faliscan

\tabto{.5in}������������������ 
\tabto{1.75in}{\fontspec{Cardo}FaliscanCDS with no stylistic set applied}\\

{\addfontfeature{StylisticSet=1}\tabto{.5in}������������������ } 
\tabto{1.75in}{\fontspec{Cardo}Faliscan CDS with Stylistic Set 1}\\


��̣��̣��̣��̣��̣��̣��̣��̣��̣��̣��̣��̣��̣��̣��̣��̣��̣��̣��̣��̣��̣��̣��̣��̣��̣��̣��̣��̣��̣��̣��̣��̣����̣��̣��̣


\end{document}




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