Rewrite CSLReferences environment...

...to avoid depending on enumitem, which plays badly with
beamer.  Instead we use a regular list environment.
Thanks to @jpcirrus for the concept.

We also restore the pre-3.1.7 format of the CSLReferences
environment, which again has two parameters. The first
determines whether a hanging indent is used (1 = yes, 0 = no),
and the second is the entry line spacing (0 = none).

Closes #9053.

data/templates/default.latex

@@ -350,15 +350,19 @@ $if(csl-refs)$
 \setlength{\cslhangindent}{1.5em}
 \newlength{\csllabelwidth}
 \setlength{\csllabelwidth}{3em}
-\newlength{\cslentryspacing}
-\setlength{\cslentryspacing}{0em}
-\usepackage{enumitem}
-\newlist{CSLReferences}{itemize}{1}
-\setlist[CSLReferences]{label={},
-  leftmargin=\cslhangindent,
-  itemindent=-1\cslhangindent,
-  parsep=\parskip,
-  itemsep=\cslentryspacing}
+\newenvironment{CSLReferences}[2] % #1 hanging-ident, #2 entry spacing
+ {\begin{list}{}{%
+  \setlength{\itemindent}{0pt}
+  \setlength{\leftmargin}{0pt}
+  \setlength{\parsep}{0pt}
+  % turn on hanging indent if param 1 is 1
+  \ifodd #1
+   \setlength{\leftmargin}{\cslhangindent}
+   \setlength{\itemindent}{-1\cslhangindent}
+  \fi
+  % set entry spacing
+  \setlength{\itemsep}{#2\baselineskip}}}
+ {\end{list}}
 \usepackage{calc}
 \newcommand{\CSLBlock}[1]{\hfill\break#1\hfill\break}
 \newcommand{\CSLLeftMargin}[1]{\parbox[t]{\csllabelwidth}{#1}}

src/Text/Pandoc/Writers/LaTeX.hs

@@ -339,14 +339,15 @@ blockToLaTeX (Div (identifier,classes,kvs) bs) = do
                then do
                  modify $ \st -> st{ stHasCslRefs = True }
                  inner <- blockListToLaTeX bs
-                 return $ (if "hanging-indent" `notElem` classes
-                               then "\\setlength{\\cslhangindent}{0em}"
-                               else mempty)
-                          $$ ("\\setlength{\\cslentryspacing}" <> braces
+                 return $ ("\\begin{CSLReferences}"
+                            <> braces
+                                (if "hanging-indent" `elem` classes
+                                    then "1"
+                                    else "0")
+                            <> braces
                                (case lookup "entry-spacing" kvs of
-                                  Nothing -> "0em"
-                                  Just s  -> (literal s <> "\\baselineskip")))
-                          $$ "\\begin{CSLReferences}"
+                                  Nothing -> "0"
+                                  Just s  -> literal s))
                           $$ inner
                           $+$ "\\end{CSLReferences}"
                else blockListToLaTeX bs