+\let\ltj@selectfont@patch\relax
+\newcount\cI\newcount\cF\newdimen\szd
+\gdef\S@#1at#2at#3\@nil{%
+ \def\@tempa{#2}
+ \ifx\@tempa\@empty\else
+ \@tempdima=\dimexpr#2-\@tempdimb\relax
+ \ifdim\@tempdima<\z@ \@tempdima=\@tempdima\fi
+ \ifdim\@tempdima>\szd \global\szd=\@tempdima\fi
+ \fi
+}
+\def\S#1{%
+ \setbox0\hbox{\fontsize{#1\jsc@mpt}{10}\selectfont
+ \@tempdimb=#1\jsc@mpt
+ \edef\@tempa{\scantextokens\expandafter{\fontname\font}\space at\space at}%
+ \expandafter\S@\@tempa\@nil
+ }%
+}
+\def\ltjs@setfontsize#1#2#3{%
+ \edef\Fsize{\the\dimexpr\directlua{tex.sprint(#2*\jsc@magscale)}pt}%
+ \@setfontsize#1{#2\jsc@mpt}{#3\jsc@mpt}}
+\def\R#1{{%
+ #1\message{^^J\string#1: \fontname\font\space (ideal: \Fsize)}%
+}}