[lucida] Odd bug with Lucida Bright Math OT, icomma and TeX Live 2015

[Bruno Voisin]

> Le 8 sept. 2015 à 20:36, Vincent Goulet <vincent.goulet at me.com> a écrit :
> 
> Should a bug report be filed against XeLaTeX and/or icomma?

First thing: testing more thoroughly today, it appears the problem goes away if icomma is loaded after fontspec and unicode-math.

That's not a fully satisfactory workaround, of course. Essentially, I think icomma is an old-style package that predates Unicode-flavoured TeXs (XeTeX or LuaTeX) and shouldn't be used with them.

The package is 13 years old. Its author, Walter Schmidt -- who also authored the psnfss rewrite at about the same time, together with lucimatx and mtpro2 later (the commercial support packages for PCTeX's Lucida and MathTime Pro 2), and a bunch of other packages <http://www.ctan.org/author/schmidt> -- has AFAIK completely disappeared from the radars of the TeX community since then. So the icomma package is essentially unsupported.

Regarding lualatex-math: its author, Philipp Stefani, is one of the authors of unicode-math. The doc says lualatex-math patches issues specific to LuaLaTeX and unrelated to unicode-math, but I'm not sure: loading icomma alone, without unicode-math, yields no problem with either XeLaTeX or LuaLaTeX. It's only when unicode-math is loaded, after icomma, that problems arise; so it doesn't seem really independent.

Also, the nice thing with both fontspec and unicode-math is that you don't have to care whether you're using XeLaTeX or LuaLaTeX. The packages include macro definitions for both (such as unicode-math-xetex.sty and unicode-math-luatex.sty for unicode-math.sty); at runtime the packages detect the engine they're run with, and pick up the appropriate set of definitions.

Having lualatex-math specific to LuaLaTeX (and maybe one day a similar xelatex-math) breaks this philosophy and makes things engine-specific, which is a bit unfortunate.

Will: I'm cc'ing this to you, just to bring the matter to your attention. No need to answer, of course! It all started with

http://tug.org/pipermail/lucida/2015-September/000619.html

Bruno