[luatex] Logging \discretionary in words containing non-letters

[Joseph Wright]

Hello all,

A little while ago I raised an issue about \discretionary in the log and
non-letters in 'words' (
http://tug.org/mailman/htdig/luatex/2015-April/005169.html). With LuaTeX
0.80 something like

    \tracingoutput=1 %
    \showboxdepth=\maxdimen
    \showboxbreadth=\maxdimen
    1-world
    \bye

gives the same log output as pdfTeX, i.e.

    ...\tenrm 1
    ...\tenrm -
    ...\discretionary
    ...\tenrm w
    ...\kern-0.27779
    ...\tenrm o
    ...\tenrm r
    ...\tenrm l
    ...\tenrm d

However, I now notice that things get a bit weird if there is more than
one "-" in a 'word'

    \tracingoutput=1 %
    \showboxdepth\maxdimen
    \showboxbreadth\maxdimen
    1-b-c 1-b-c 1a-b-c a-b-1-d-e
    \bye

gives

    ...\tenrm 1
    ...\tenrm -
    ...\discretionary
    ...\tenrm b
    ...\tenrm -
    ...\tenrm c
    ...\glue 3.33333 plus 1.66666 minus 1.11111
    ...\tenrm 1
    ...\tenrm -
    ...\discretionary
    ...\tenrm b
    ...\tenrm -
    ...\tenrm c
    ...\glue 3.33333 plus 1.66666 minus 1.11111
    ...\tenrm 1
    ...\tenrm a
    ...\tenrm -
    ...\discretionary
    ...\tenrm b
    ...\tenrm -
    ...\discretionary
    ...\tenrm c
    ...\glue 3.33333 plus 1.66666 minus 1.11111
    ...\tenrm a
    ...\tenrm -
    ...\tenrm b
    ...\tenrm -
    ...\tenrm 1
    ...\tenrm -
    ...\discretionary
    ...\tenrm d
    ...\tenrm -
    ...\tenrm e

with LuaTeX 0.80.0 whereas pdfTeX marks every "-" as a \discretionary.
Presumably this is not a deliberate change?
--
Joseph Wright