Hi,
the below example shows two bugs with \rightmarginkern: it doesn't work
with the discretionary hyphen (line 5), and it doesn't work in the last
line (this latter bug was fixed in pdftex 1.40.11, see
<http://sarovar.org/tracker/index.php?func=detail&aid=4292&group_id=106&atid=493>)
\pdftracingfonts2
\hsize3.9cm
\rpcode\font`\-300
\rpcode\font`\.300
\pdfprotrudechars2
\parindent0pt
\parfillskip0pt
\splittopskip0pt
\newbox\splitbox
\setbox0\vbox{testing protrusion testing- protrusion
testing protrusion testing protrusion.}
\unvcopy0
\medskip
\loop\ifvbox0
\setbox\splitbox\vsplit0 to\baselineskip
\unvbox\splitbox\setbox\splitbox=\lastbox
\hbox to \hsize{\expandafter\unhbox\expandafter\splitbox
\expandafter\kern\rightmarginkern\splitbox}
\repeat
\bye
--
Robert
