On 1/13/2026 8:25 AM, luigi scarso wrote:
On Tue, 13 Jan 2026 at 01:51, Robert via luatex <[email protected]
<mailto:[email protected]>> wrote:
On 12.01.26 15:58, luigi scarso wrote:
>
> Do you have the same with the luatex-plain format ?
>
Here is a MWE for -ini mode, which also only yields two protruded
hyphens instead of three (with luatex or luahbtex 1.21 from TL25), so
maybe it's something that the luatex-plain format (which I can't test
right now) fixes, not something that the vanilla plain format breaks?
\catcode`\{=1
\catcode`\}=2
\input luatexconfig.tex % enable luatex primitives
\input luatexiniconfig.tex
\outputmode=1
\hsize=10cm
\vsize=10cm
\def\\{\hfil\penalty-10000}
\font\x=cmr10 \x
\baselineskip=12pt
\parfillskip=0pt plus 1fil
\protrudechars2
\lpcode\font`-=500
\noindent
\vrule width 4cm height 1mm\\
-\\
-foo\\
-\kern0pt foo\\
\vrule width 4cm height 1mm
\end
Best,
It doesn't seem like a critical bug -- if it is, maybe we can call it a
feature.
I'll leave it to Vitek to investigate.
In case, we can add \tracingall and see the trace.
\input luatexconfig.tex % enable luatex primitives
\input luatexiniconfig.tex
\def\tracingall{%
\tracingonline=1
\tracingcommands=3
\tracingstats=2
\tracingpages=1
\tracingoutput=1
\tracinglostchars=2
\tracingmacros=2
\tracingparagraphs=1
\tracingrestores=1
\showboxbreadth=65535
\showboxdepth=65535
\errorstopmode
\tracinggroups=1
\tracingifs=1
\tracingscantokens=1
\tracingnesting=1
\tracingassigns=2
}
\tracingall
--
luigi
Indeed. And tracing shows this:
\hbox(6.94444+0.0)x284.52756, glue set 272.86084fil, direction TLT
..\kern-5.00002 (left margin)
..\x -
.\hbox(6.94444+0.0)x284.52756, glue set 267.86084fil, direction TLT
..\discretionary (penalty 0)
...< \x -
...= \x -
where the difference is in setting
\automatichyphenmode = 1
Which is what we do in luatex-plain.tex indeed. There are various
conditions checked for what makes a left or right edge and that mode
avoids creating a discretionary node that hides the hyphen. There have
been plenty discussions about hyphens in the past and this was one of
the solutions to accomodate various scenarios.
Hans
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