[XeTeX] Unexplained behavior

[Bogdan Butnaru]

On Sat, Jan 15, 2011 at 22:44, Bogdan Butnaru <bogdanb+xetex at gmail.com> wrote:
> I want a typed em-dash to
> 1) in running text, be typeset with a small space around it
> 1a) ideally the space should be thin even if the source contains
> spaces around it
> 1b) ideally the space should be glue rather than a kern, so it can
> stretch a bit in stretched lines
> 2) line breaks should be forbidden before a dash, but should be allowed after
> 3) if a dash begins/ends a line, the space before/after it should disappear
> 4) and there should be no weird behavior otherwise...

Oh,  and I forgot another one:
5) Linebreaks should be forbidden after an em dash if another
punctuation mark follows it.

Since I couldn’t  do what I wanted above I resorted to just enabling
\XeTeXdashbreakstate=1, but I noticed that even that doesn’t handle
point 5, I’ve seen it put a linebreak between an emdash and a closing
quote.

Sigh...

—Bogdan Butnaru