[luatex] luatex/luaotf bug: kerns are missing in discretionary nodes

Petr Olsak petr at olsak.net
Thu Dec 12 21:02:56 CET 2013

Philipp Gesang:

> the kerns do show up in base mode:
>  \font\f=file:lmroman10-regular:mode=base \f

Thank you very much for your answer. But there is a misunderstanding. I 
needn't to help with my special document because I am not using luaTeX for 
my documents. Moreover, I personally know that there is the mode=base.

I want only to report this serious bug. And it is really serious: the 
mode=node is set as default. It means that cca 90 percent documents 
produced by luaTeX has bad kerning and this is not a good reputation for 
luaTeX. Many users are not able to notice it and they produce bad 

My question is: what will do the developers? OK, they are informed already 
so my bug report is irrelevant. How many users will waste the time with 
tracing the problem in the future until the bug will be solved?

>From luaotfload documentation:

> node mode works by processing TEX's internal node list directly at the 
> Lua end and supports a wider range of OpenType features.
> By default luaotfload is in node mode, and base mode has to be requested 
> where needed, e. g. for math fonts.

The last sentecne have to be polonged: ... or you need to typeset the 
text by correct kerning because default setting produces bad kerns.

Best regards

Petr Olsak

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