[XeTeX] Is it a bug on inter-char tokens?

[Yin Dian]

Hi all,

It seems that \char cannot trigger the right inter-char token when the
inter-char token between boundary and the specific class is not empty.
The following code shows a minimal example.

\XeTeXcharclass 65=22
\XeTeXinterchartoks 22 0={\message{22-0}}
\XeTeXinterchartoks 0 22={\message{0-22}}
\XeTeXinterchartoks 22 255={\message{22-255}} % comment these two lines
\XeTeXinterchartoks 255 22={\message{255-22}} % to get the right result
\XeTeXinterchartokenstate=1
\tracingall
hello \char 65 world
\bye

It is expected to trigger the inter-char token between 22 and 0 after
the \char command. However, the inter-char token between 255 and 22 is
triggered, and the log file suggests the \char 65 is considered a
blank space, and thus not displayed in the pdf file. Leaving the
inter-char token between 255 and 22 empty could generate the right
result.

I'm using the latest xetex-dev in W32TeX. Can this "bug" be found on
other platforms?

Regards.

-YIN Dian