Adapt template to pandoc's new babel use

jgm/pandoc#7604

inst/rmarkdown/templates/thesis/skeleton/template.tex

@@ -5,9 +5,9 @@
 
 %\documentclass[$if(fontsize)$$fontsize$,$endif$$if(lang)$$babel-lang$,$endif$$if(papersize)$$papersize$paper,$endif$$for(classoption)$$classoption$$sep$,$endfor$]{$documentclass$} %LCR
 $if(book_size)$ % if the book is being rendered for print, force twoside option
-\documentclass[$if(fontsize)$$fontsize$,$endif$$if(lang)$$babel-lang$,$endif$$if(papersize)$$papersize$paper,twoside,$endif$$for(classoption)$$classoption$$sep$,$endfor$]{$documentclass$} %LCR
+\documentclass[$if(fontsize)$$fontsize$,$endif$$if(papersize)$$papersize$paper,twoside,$endif$$for(classoption)$$classoption$$sep$,$endfor$]{$documentclass$} %LCR
 $else$ % if not, force the oneside and a4paper options, which seem to be the only reasonable defaults
-\documentclass[$if(fontsize)$$fontsize$,$endif$$if(lang)$$babel-lang$,$endif$a4paper,oneside,$for(classoption)$$classoption$$sep$,$endfor$]{$documentclass$} %LCR
+\documentclass[$if(fontsize)$$fontsize$,$endif$a4paper,oneside,$for(classoption)$$classoption$$sep$,$endfor$]{$documentclass$} %LCR
 $endif$
 $if(fontfamily)$
 \usepackage[$for(fontfamilyoptions)$$fontfamilyoptions$$sep$,$endfor$]{$fontfamily$}
@@ -96,19 +96,33 @@
             breaklinks=true}
 \urlstyle{same}  % don't use monospace font for urls
 $if(lang)$
-\ifnum 0\ifxetex 1\fi\ifluatex 1\fi=0 % if pdftex
-  \usepackage[shorthands=off,$for(babel-otherlangs)$$babel-otherlangs$,$endfor$main=$babel-lang$]{babel}
-$if(babel-newcommands)$
-  $babel-newcommands$
-$endif$
+\ifLuaTeX
+\usepackage[bidi=basic]{babel}
 \else
-  \usepackage{polyglossia}
-  \setmainlanguage[$polyglossia-lang.options$]{$polyglossia-lang.name$}
-$for(polyglossia-otherlangs)$
-  \setotherlanguage[$polyglossia-otherlangs.options$]{$polyglossia-otherlangs.name$}
-$endfor$
+\usepackage[bidi=default]{babel}
 \fi
+$if(babel-lang)$
+\babelprovide[main,import]{$babel-lang$}
+$if(mainfont)$
+\ifPDFTeX
+\else
+\babelfont{rm}[$for(mainfontoptions)$$mainfontoptions$$sep$,$endfor$$if(mainfontfallback)$,RawFeature={fallback=mainfontfallback}$endif$]{$mainfont$}
+\fi
+$endif$
 $endif$
+$for(babel-otherlangs)$
+\babelprovide[import]{$babel-otherlangs$}
+$endfor$
+$for(babelfonts/pairs)$
+\babelfont[$babelfonts.key$]{rm}{$babelfonts.value$}
+$endfor$
+% get rid of language-specific shorthands (see #6817):
+\let\LanguageShortHands\languageshorthands
+\def\languageshorthands#1{}
+$endif$
+$for(header-includes)$
+$header-includes$
+$endfor$
 $if(natbib)$
 \usepackage$if(natbiboptions)$[$for(natbiboptions)$$natbiboptions$$sep$,$endfor$]$endif${natbib}
 \bibliographystyle{$if(biblio-style)$$biblio-style$$else$plainnat$endif$}
@@ -247,10 +261,6 @@
 % https://github.com/jgm/pandoc/issues/5801
 \renewcommand{\linethickness}{0.05em}
 
-$for(header-includes)$
-$header-includes$
-$endfor$
-
 %%%%%%%%%%%%% BEGIN DOCUMENT %%%%%%%%%%%%%
 \begin{document}