[Dev-luatex] Disappearing quoteleft in luatex

[Marcel Fabian Krüger]

On Fri, Feb 07, 2020 at 09:39:02AM +0900, Norbert Preining wrote:
> Dear all,
> 
> I see a strange thing happening with the following document all with
> uptodate TeX Live:
> 
> \documentclass{article}
> \usepackage{fontspec}
> \setmainfont{Gaultier}
> \begin{document}
> Hello `World'
> \end{document}
> 
> xelatex: ok
> lualatex: quoteleft character is missing
> lualatex-dev with [RawFeature={mode=harf;}]: ok
> 
> So it seems that the lualatex font loader seems to be broken here.
> 
> The character is present in the font
> 	325 (0x145) U+2018 "quoteleft" LEFT SINGLE QUOTATION MARK
> and separate from the quoteright.

The "quoteleft" is present, but you are dealing with an odd font which
does not have a ASCII "grave" (U+0060). Given that the replacement is
implemented as a glyph substitution it only works if the original glyph
exists.

> 
> Any suggestions how to fix these kind of errors?

Use a proper font or input ‘ directly. You can probably also manually
add a lookup to the fontloader which includes these replacement without
checking if the original characters exists, but I'm currently not sure
if that might break something.

Best,
Marcel