[XeTeX] Nested \textit in an italic fontinstance

[nickkk at phonecoop.coop]

Many thanks for your help in resolving my problem.

I now appreciate it is best to try and avoid specifying Italic fonts with 
\newfontinstance.
  
Thinking back, I realise that I'd based my subheading fontinstances (with 
swashes) on the example on p14 of the fontspec 1.10 documentation 
where "Hoefler Text Italic" is used as the fontname in a fontspec command, 
though for AAT fonts not OpenType.

And I think my minimal example muddied some of the water.  I was trying to put 
a technical expression (which my macro italicizes) into a titlesec subheading 
with italics and optionally swashes (applied by 
\newfontinstance\subheadingfont).  The net result was that my technical 
expression did not come out italic, but upright.

\emph wasn't quite what I wanted, for example when the technical expression 
was the only content of the subheading, and came out upright.

But using 
\newfontinstance\subheadingfont{Warnock Pro}, or 
\newfontinstance\swashes[Contextuals=Swash]{Warnock Pro}
and \textit or \itshape at the relevant point with titlesec solves the 
problem.

Would some kind of warning be appropriate if an Italic font were specified as 
the font name? Or did I miss it? (I'm sure I won't be the last one to do 
this!)

Thanks again.

Nick