Make LaTeX writer sensitive to empty_paragraphs extension.

Closes #9443.

MANUAL.txt

@@ -3549,7 +3549,7 @@ input formats
 :  `docx`, `html`
 
 output formats
-:  `docx`, `odt`, `opendocument`, `html`
+:  `docx`, `odt`, `opendocument`, `html`, `latex`
 
 #### Extension: `native_numbering` ####
 

src/Text/Pandoc/Extensions.hs

@@ -612,6 +612,7 @@ getAllExtensions f = universalExtensions <> getAll f
     , Ext_raw_tex
     , Ext_task_lists
     , Ext_literate_haskell
+    , Ext_empty_paragraphs
     ]
   getAll "beamer"          = getAll "latex"
   getAll "context"         = autoIdExtensions <>

src/Text/Pandoc/Writers/LaTeX.hs

@@ -404,7 +404,13 @@ blockToLaTeX (Para [Str ".",Space,Str ".",Space,Str "."]) = do
      then blockToLaTeX (RawBlock "latex" "\\pause")
      else inlineListToLaTeX [Str ".",Space,Str ".",Space,Str "."]
 blockToLaTeX (Para lst) =
-  inlineListToLaTeX lst
+  if null lst
+     then do
+       opts <- gets stOptions
+       if isEnabled Ext_empty_paragraphs opts
+          then pure "\\hfill\\par"
+          else pure mempty
+     else inlineListToLaTeX lst
 blockToLaTeX (LineBlock lns) =
   blockToLaTeX $ linesToPara lns
 blockToLaTeX (BlockQuote lst) = do