Incorrect rendering of intersecting strokes in variable fonts

Dear list,

I would like to report a rendering issue with variable OpenType fonts in ConTeXt.

When using a variable font, the intersecting strokes of certain glyphs are rendered as hollow (appear镂空) in the context of TeX. 
This issue seems to be related to the CFF2 parser (font-cff.lmt) and its handling of subroutinized glyph outlines.
And this issue does not occur with TrueType (TTF) variable fonts. 

A minimal working example to reproduce the bug is as follows:

```tex
\starttext

\definefontfeature[bold][axis={wght=600}]

\definedfont[name:wenyuanserifscvf*bold at 24pt]% or Source Han Serif SC VF

称数刻从样西标延还挑依保着A
\stoptext

Screenshot:https://www.pasteboard.co/umKgSWdzf5Dy.png
ConTeXt version: 2026.07.29 11:46 (tex live)
Operating System: macOS 
Font: wenyuanserifscvf.otf [https://github.com/takushun-wu/WenYuanFonts] 
          or SourceHanSerifCN-VF.otf [https://mirror.tuna.tsinghua.edu.cn/adobe-fonts/source-han-serif/Variable/OTF/Subset/SourceHanSerifCN-VF.otf]

Note: The font I originally used (WenYuan Serif SC VF) has GPOS tables, 
which may trigger errors during compilation. 
However, if you wait a moment or compile the document a few times, 
the final output (with the hollow strokes) will still appear.
Alternatively, you can use SourceHanSerifCN-VF.otf(思源宋体) , 
which also exhibits the same hollow-stroke issue, 
but without any GPOS-related errors. 
This makes it much easier and faster to reproduce the problem reliably, 
as there are no compilation interruptions.

Could you please look into this issue? Thank you for your time and effort.

Best regards,
autumnus
___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the Wiki!

maillist : [email protected] / https://mailman.ntg.nl/mailman3/lists/ntg-context.ntg.nl
webpage  : https://www.pragma-ade.nl / https://context.aanhet.net (mirror)
archive  : https://github.com/contextgarden/context
wiki     : https://wiki.contextgarden.net
___________________________________________________________________________________