[XeTeX] Feedback on W32 Port of XeTeX v0.994

[Jonathan Kew]

On 13 Jun 2006, at 10:21 am, Toralf Senger wrote:

> Last issue I noticed: Independant of how I inlcude the font (with  
> fontspec, \font= or with my stylefile), the pnum feature  
> (Proportional Figures) gave a strange result: when I type several  
> times the nunber 'one', like 11111111, they end up in visualy quite  
> disturbung groups of two digits, like 11 11 11 11..not separeted by  
> much, but still quite visible. Other Opentype aware applications  
> like Adobe Indesign or Illustrator dont to that and neither does  
> PDFTex do that..so is this a bug or a feature (the result of the  
> script that is behind pnum)?

I've done some investigation, and this appears to be caused by a bug  
in the ICU layout implementation of OpenType kerning (which is used  
internally to support the proportional digit spacing in Adobe's  
fonts). Alternate kerns in a sequence are skipped. :(

You can demonstrate a similar effect by using Latin Modern and  
comparing "AV", "VA", "AVAVAV", and "VAVAVA".

So I'll need to look into this... thanks for the report.

JK