LaTeX Template: Improve package selections (#5193)

* Use Babel for LuaTeX.  There are a number of bugs in Polyglossia under LuaLaTeX with common languages, e.g. <https://github.com/reutenauer/polyglossia/issues/182>.

* Load xcolor. The `xcolor` package must be loaded before the `footnote` package, which we load to fix foonotes in tables. Closes #4861.

* Load xurl if available. This breaks URLs in more locations. Only available with TeX Live 2018 and later.

* Remove obsolete fixltx2e package

* Reindent. Use two spaces to be consistent internally and with other templates.

* Use `bookmark` if available. The `bookmark` package can sometimes correct the levels of headings where `hyperref` cannot: see <https://komascript.de/release3.26>.

* Update LaTeX tests

4 files changed, 69 insertions, 64 deletions

diff --git a/test/lhs-test.latex b/test/lhs-test.latex
index 015a55255..5584b2cfa 100644
--- a/test/lhs-test.latex
+++ b/test/lhs-test.latex
@@ -1,11 +1,11 @@
 \PassOptionsToPackage{unicode=true}{hyperref} % options for packages loaded elsewhere
 \PassOptionsToPackage{hyphens}{url}
 %
-\documentclass[]{article}
+\documentclass[
+]{article}
 \usepackage{lmodern}
 \usepackage{amssymb,amsmath}
 \usepackage{ifxetex,ifluatex}
-\usepackage{fixltx2e} % provides \textsubscript
 \ifnum 0\ifxetex 1\fi\ifluatex 1\fi=0 % if pdftex
   \usepackage[T1]{fontenc}
   \usepackage[utf8]{inputenc}
@@ -16,25 +16,26 @@
 \fi
 % use upquote if available, for straight quotes in verbatim environments
 \IfFileExists{upquote.sty}{\usepackage{upquote}}{}
-% use microtype if available
-\IfFileExists{microtype.sty}{%
-\usepackage[]{microtype}
-\UseMicrotypeSet[protrusion]{basicmath} % disable protrusion for tt fonts
+\IfFileExists{microtype.sty}{% use microtype if available
+  \usepackage[]{microtype}
+  \UseMicrotypeSet[protrusion]{basicmath} % disable protrusion for tt fonts
 }{}
 \makeatletter
-\@ifundefined{KOMAClassName}{%
+\@ifundefined{KOMAClassName}{% if non-KOMA class
   \IfFileExists{parskip.sty}{%
     \usepackage{parskip}
   }{% else
     \setlength{\parindent}{0pt}
     \setlength{\parskip}{6pt plus 2pt minus 1pt}}
-}{% else
+}{% if KOMA class
   \KOMAoptions{parskip=half}}
 \makeatother
-\usepackage{hyperref}
+\usepackage{xcolor}
+\IfFileExists{xurl.sty}{\usepackage{xurl}}{} % add URL line breaks if available
+\IfFileExists{bookmark.sty}{\usepackage{bookmark}}{\usepackage{hyperref}}
 \hypersetup{
-            pdfborder={0 0 0},
-            breaklinks=true}
+  pdfborder={0 0 0},
+  breaklinks=true}
 \urlstyle{same}  % don't use monospace font for urls
 \usepackage{color}
 \usepackage{fancyvrb}
@@ -80,12 +81,12 @@
 \setcounter{secnumdepth}{0}
 % Redefines (sub)paragraphs to behave more like sections
 \ifx\paragraph\undefined\else
-\let\oldparagraph\paragraph
-\renewcommand{\paragraph}[1]{\oldparagraph{#1}\mbox{}}
+  \let\oldparagraph\paragraph
+  \renewcommand{\paragraph}[1]{\oldparagraph{#1}\mbox{}}
 \fi
 \ifx\subparagraph\undefined\else
-\let\oldsubparagraph\subparagraph
-\renewcommand{\subparagraph}[1]{\oldsubparagraph{#1}\mbox{}}
+  \let\oldsubparagraph\subparagraph
+  \renewcommand{\subparagraph}[1]{\oldsubparagraph{#1}\mbox{}}
 \fi
 
 % set default figure placement to htbp
diff --git a/test/lhs-test.latex+lhs b/test/lhs-test.latex+lhs
index fc16ff95a..f22da75f3 100644
--- a/test/lhs-test.latex+lhs
+++ b/test/lhs-test.latex+lhs
@@ -1,11 +1,11 @@
 \PassOptionsToPackage{unicode=true}{hyperref} % options for packages loaded elsewhere
 \PassOptionsToPackage{hyphens}{url}
 %
-\documentclass[]{article}
+\documentclass[
+]{article}
 \usepackage{lmodern}
 \usepackage{amssymb,amsmath}
 \usepackage{ifxetex,ifluatex}
-\usepackage{fixltx2e} % provides \textsubscript
 \ifnum 0\ifxetex 1\fi\ifluatex 1\fi=0 % if pdftex
   \usepackage[T1]{fontenc}
   \usepackage[utf8]{inputenc}
@@ -16,25 +16,26 @@
 \fi
 % use upquote if available, for straight quotes in verbatim environments
 \IfFileExists{upquote.sty}{\usepackage{upquote}}{}
-% use microtype if available
-\IfFileExists{microtype.sty}{%
-\usepackage[]{microtype}
-\UseMicrotypeSet[protrusion]{basicmath} % disable protrusion for tt fonts
+\IfFileExists{microtype.sty}{% use microtype if available
+  \usepackage[]{microtype}
+  \UseMicrotypeSet[protrusion]{basicmath} % disable protrusion for tt fonts
 }{}
 \makeatletter
-\@ifundefined{KOMAClassName}{%
+\@ifundefined{KOMAClassName}{% if non-KOMA class
   \IfFileExists{parskip.sty}{%
     \usepackage{parskip}
   }{% else
     \setlength{\parindent}{0pt}
     \setlength{\parskip}{6pt plus 2pt minus 1pt}}
-}{% else
+}{% if KOMA class
   \KOMAoptions{parskip=half}}
 \makeatother
-\usepackage{hyperref}
+\usepackage{xcolor}
+\IfFileExists{xurl.sty}{\usepackage{xurl}}{} % add URL line breaks if available
+\IfFileExists{bookmark.sty}{\usepackage{bookmark}}{\usepackage{hyperref}}
 \hypersetup{
-            pdfborder={0 0 0},
-            breaklinks=true}
+  pdfborder={0 0 0},
+  breaklinks=true}
 \urlstyle{same}  % don't use monospace font for urls
 \usepackage{listings}
 \newcommand{\passthrough}[1]{#1}
@@ -45,12 +46,12 @@
 \setcounter{secnumdepth}{0}
 % Redefines (sub)paragraphs to behave more like sections
 \ifx\paragraph\undefined\else
-\let\oldparagraph\paragraph
-\renewcommand{\paragraph}[1]{\oldparagraph{#1}\mbox{}}
+  \let\oldparagraph\paragraph
+  \renewcommand{\paragraph}[1]{\oldparagraph{#1}\mbox{}}
 \fi
 \ifx\subparagraph\undefined\else
-\let\oldsubparagraph\subparagraph
-\renewcommand{\subparagraph}[1]{\oldsubparagraph{#1}\mbox{}}
+  \let\oldsubparagraph\subparagraph
+  \renewcommand{\subparagraph}[1]{\oldsubparagraph{#1}\mbox{}}
 \fi
 
 % set default figure placement to htbp
diff --git a/test/writer.latex b/test/writer.latex
index 46e9b7a38..f6b074099 100644
--- a/test/writer.latex
+++ b/test/writer.latex
@@ -1,11 +1,11 @@
 \PassOptionsToPackage{unicode=true}{hyperref} % options for packages loaded elsewhere
 \PassOptionsToPackage{hyphens}{url}
 %
-\documentclass[]{article}
+\documentclass[
+]{article}
 \usepackage{lmodern}
 \usepackage{amssymb,amsmath}
 \usepackage{ifxetex,ifluatex}
-\usepackage{fixltx2e} % provides \textsubscript
 \ifnum 0\ifxetex 1\fi\ifluatex 1\fi=0 % if pdftex
   \usepackage[T1]{fontenc}
   \usepackage[utf8]{inputenc}
@@ -16,28 +16,29 @@
 \fi
 % use upquote if available, for straight quotes in verbatim environments
 \IfFileExists{upquote.sty}{\usepackage{upquote}}{}
-% use microtype if available
-\IfFileExists{microtype.sty}{%
-\usepackage[]{microtype}
-\UseMicrotypeSet[protrusion]{basicmath} % disable protrusion for tt fonts
+\IfFileExists{microtype.sty}{% use microtype if available
+  \usepackage[]{microtype}
+  \UseMicrotypeSet[protrusion]{basicmath} % disable protrusion for tt fonts
 }{}
 \makeatletter
-\@ifundefined{KOMAClassName}{%
+\@ifundefined{KOMAClassName}{% if non-KOMA class
   \IfFileExists{parskip.sty}{%
     \usepackage{parskip}
   }{% else
     \setlength{\parindent}{0pt}
     \setlength{\parskip}{6pt plus 2pt minus 1pt}}
-}{% else
+}{% if KOMA class
   \KOMAoptions{parskip=half}}
 \makeatother
 \usepackage{fancyvrb}
-\usepackage{hyperref}
+\usepackage{xcolor}
+\IfFileExists{xurl.sty}{\usepackage{xurl}}{} % add URL line breaks if available
+\IfFileExists{bookmark.sty}{\usepackage{bookmark}}{\usepackage{hyperref}}
 \hypersetup{
-            pdftitle={Pandoc Test Suite},
-            pdfauthor={John MacFarlane; Anonymous},
-            pdfborder={0 0 0},
-            breaklinks=true}
+  pdftitle={Pandoc Test Suite},
+  pdfauthor={John MacFarlane; Anonymous},
+  pdfborder={0 0 0},
+  breaklinks=true}
 \urlstyle{same}  % don't use monospace font for urls
 \VerbatimFootnotes % allows verbatim text in footnotes
 \usepackage{graphicx,grffile}
@@ -58,12 +59,12 @@
 \setcounter{secnumdepth}{0}
 % Redefines (sub)paragraphs to behave more like sections
 \ifx\paragraph\undefined\else
-\let\oldparagraph\paragraph
-\renewcommand{\paragraph}[1]{\oldparagraph{#1}\mbox{}}
+  \let\oldparagraph\paragraph
+  \renewcommand{\paragraph}[1]{\oldparagraph{#1}\mbox{}}
 \fi
 \ifx\subparagraph\undefined\else
-\let\oldsubparagraph\subparagraph
-\renewcommand{\subparagraph}[1]{\oldsubparagraph{#1}\mbox{}}
+  \let\oldsubparagraph\subparagraph
+  \renewcommand{\subparagraph}[1]{\oldsubparagraph{#1}\mbox{}}
 \fi
 
 % set default figure placement to htbp
diff --git a/test/writers-lang-and-dir.latex b/test/writers-lang-and-dir.latex
index de382641d..7b13594da 100644
--- a/test/writers-lang-and-dir.latex
+++ b/test/writers-lang-and-dir.latex
@@ -1,11 +1,12 @@
 \PassOptionsToPackage{unicode=true}{hyperref} % options for packages loaded elsewhere
 \PassOptionsToPackage{hyphens}{url}
 %
-\documentclass[english,]{article}
+\documentclass[
+  english,
+]{article}
 \usepackage{lmodern}
 \usepackage{amssymb,amsmath}
 \usepackage{ifxetex,ifluatex}
-\usepackage{fixltx2e} % provides \textsubscript
 \ifnum 0\ifxetex 1\fi\ifluatex 1\fi=0 % if pdftex
   \usepackage[T1]{fontenc}
   \usepackage[utf8]{inputenc}
@@ -16,25 +17,26 @@
 \fi
 % use upquote if available, for straight quotes in verbatim environments
 \IfFileExists{upquote.sty}{\usepackage{upquote}}{}
-% use microtype if available
-\IfFileExists{microtype.sty}{%
-\usepackage[]{microtype}
-\UseMicrotypeSet[protrusion]{basicmath} % disable protrusion for tt fonts
+\IfFileExists{microtype.sty}{% use microtype if available
+  \usepackage[]{microtype}
+  \UseMicrotypeSet[protrusion]{basicmath} % disable protrusion for tt fonts
 }{}
 \makeatletter
-\@ifundefined{KOMAClassName}{%
+\@ifundefined{KOMAClassName}{% if non-KOMA class
   \IfFileExists{parskip.sty}{%
     \usepackage{parskip}
   }{% else
     \setlength{\parindent}{0pt}
     \setlength{\parskip}{6pt plus 2pt minus 1pt}}
-}{% else
+}{% if KOMA class
   \KOMAoptions{parskip=half}}
 \makeatother
-\usepackage{hyperref}
+\usepackage{xcolor}
+\IfFileExists{xurl.sty}{\usepackage{xurl}}{} % add URL line breaks if available
+\IfFileExists{bookmark.sty}{\usepackage{bookmark}}{\usepackage{hyperref}}
 \hypersetup{
-            pdfborder={0 0 0},
-            breaklinks=true}
+  pdfborder={0 0 0},
+  breaklinks=true}
 \urlstyle{same}  % don't use monospace font for urls
 \setlength{\emergencystretch}{3em}  % prevent overfull lines
 \providecommand{\tightlist}{%
@@ -42,12 +44,12 @@
 \setcounter{secnumdepth}{0}
 % Redefines (sub)paragraphs to behave more like sections
 \ifx\paragraph\undefined\else
-\let\oldparagraph\paragraph
-\renewcommand{\paragraph}[1]{\oldparagraph{#1}\mbox{}}
+  \let\oldparagraph\paragraph
+  \renewcommand{\paragraph}[1]{\oldparagraph{#1}\mbox{}}
 \fi
 \ifx\subparagraph\undefined\else
-\let\oldsubparagraph\subparagraph
-\renewcommand{\subparagraph}[1]{\oldsubparagraph{#1}\mbox{}}
+  \let\oldsubparagraph\subparagraph
+  \renewcommand{\subparagraph}[1]{\oldsubparagraph{#1}\mbox{}}
 \fi
 
 % set default figure placement to htbp
@@ -55,7 +57,7 @@
 \def\fps@figure{htbp}
 \makeatother
 
-\ifnum 0\ifxetex 1\fi\ifluatex 1\fi=0 % if pdftex
+\ifnum 0\ifxetex 1\fi=0 % if pdftex or luatex
   \usepackage[shorthands=off,ngerman,british,nswissgerman,spanish,french,main=english]{babel}
   \newcommand{\textgerman}[2][]{\foreignlanguage{ngerman}{#2}}
   \newenvironment{german}[2][]{\begin{otherlanguage}{ngerman}}{\end{otherlanguage}}
@@ -66,7 +68,7 @@
   \AddBabelHook{spanish}{afterextras}{\renewcommand{\textspanish}[2][]{\foreignlanguage{spanish}{##2}}}
   \newcommand{\textfrench}[2][]{\foreignlanguage{french}{#2}}
   \newenvironment{french}[2][]{\begin{otherlanguage}{french}}{\end{otherlanguage}}
-\else
+\else % if xetex
   % load polyglossia as late as possible as it *could* call bidi if RTL lang (e.g. Hebrew or Arabic)
   \usepackage{polyglossia}
   \setmainlanguage[]{english}