LaTeX writer: avoid error on refs div with empty citations.

If there are no citations, don't emit an empty CSLReferences
environment.

Closes #10185.

src/Text/Pandoc/Writers/LaTeX.hs

@@ -375,8 +375,9 @@ blockToLaTeX (Div (identifier,classes,kvs) bs) = do
      then modify $ \st -> st{ stIncremental = True }
      else when (beamer && "nonincremental" `elem` classes) $
              modify $ \st -> st { stIncremental = False }
-  result <- if identifier == "refs" || -- <- for backwards compatibility
-               "csl-bib-body" `elem` classes
+  result <- if (identifier == "refs" || -- <- for backwards compatibility
+                "csl-bib-body" `elem` classes) &&
+               (not (null bs))
                then do
                  modify $ \st -> st{ stHasCslRefs = True }
                  inner <- blockListToLaTeX bs

test/command/10185.md

@@ -0,0 +1,44 @@
+```
+% pandoc -t latex --citeproc
+Lorem ipsum
+
+# References
+
+::: #refs
+:::
+^D
+Lorem ipsum
+
+\section{References}\label{references}
+```
+
+```
+% pandoc -t latex --citeproc
+---
+references:
+- id: foo
+  type: book
+  title: The Title
+  author: John Doe
+...
+
+Lorem ipsum [@foo].
+
+# References
+
+::: #refs
+:::
+^D
+Lorem ipsum (John Doe, n.d.).
+
+\section{References}\label{references}
+
+\phantomsection\label{refs}
+\begin{CSLReferences}{1}{0}
+\bibitem[\citeproctext]{ref-foo}
+John Doe. n.d. \emph{The Title}.
+
+\end{CSLReferences}
+
+```
+