There seems to be some interaction with \pretolerance.
If you add \pretolerance=-10000, LuaTeX does break at the penalty.
Let me try to understand what's going on...
On http://www.tug.org/utilities/plain/cseq.html#pretolerance-rp it says
that if you set pretolerance to a negative value (and indeed -1 is
enough to get the expected result), TeX will skip its first attempt to
build the paragraph without hyphenation.
This means that:
* in pdfTeX, the first attempt results in breaking at the discretionary
due to hyphenpenalty
* in LuaTeX, the hyphenpenalty is not taken into account in the first
attempt (which is the big difference), but if the first attempt is
skipped with pretolerance=-1, then it's taken into account in the
second attempt
Am I correct?
Would it be possible to make hyphenpenalty taken into account in the
first attempt?
Thank you,
--
Elie
