Markdown writer: New approach for citations.

* Reverts 1.11 change that caused citations to be rendered as
  markdown citations, even if `--biblio` was specified, unless
  `citation` extension is disabled.  Now, formatted citations
  are always printed if `--biblio` was specified.  If you want to
  reformat markdown keeping pandoc markdown citations intact,
  just don't specify `--biblio`.

* Reverted now unnecessary changes to Text.Pandoc.Biblio adding the raw
  block to mark the bibliography, and to Text.Pandoc.Writers.Markdown
  to remove the bibliography if `citations` not specified.

* If the content of a `Cite` inline is a `RawInline "latex"`, which
  means that a LaTeX citation command was parsed and `--biblio` wasn't
  specified, then render it as a pandoc markdown citation.  This means
  that `pandoc -f latex -t markdown`, without `--biblio`, will convert
  LaTeX citation commands to pandoc markdown citations.

src/Text/Pandoc/Biblio.hs

@@ -54,7 +54,7 @@ processBiblio (Just style) r p =
       cits_map   = M.fromList $ zip grps (citations result)
       biblioList = map (renderPandoc' style) (bibliography result)
       Pandoc m b = bottomUp mvPunct . deNote . bottomUp (processCite style cits_map) $ p'
-  in  Pandoc m $ b ++ (RawBlock "pandoc" "references" : biblioList)
+  in  Pandoc m $ b ++ biblioList
 
 -- | Substitute 'Cite' elements with formatted citations.
 processCite :: Style -> M.Map [Citation] [FormattedOutput] -> Inline -> Inline

src/Text/Pandoc/Writers/Markdown.hs

@@ -61,8 +61,7 @@ writeMarkdown opts document =
   evalState (pandocToMarkdown opts{
                   writerWrapText = writerWrapText opts &&
                   not (isEnabled Ext_hard_line_breaks opts) }
-             document') def
-   where document' = maybeRemoveBiblio opts document
+             document) def
 
 -- | Convert Pandoc to plain text (like markdown, but without links,
 -- pictures, or inline formatting).
@@ -72,16 +71,7 @@ writePlain opts document =
                  writerExtensions = Set.delete Ext_escaped_line_breaks $
                                     writerExtensions opts }
               document') def{ stPlain = True }
-    where document' = plainify $ maybeRemoveBiblio opts document
-
--- If we're rendering citations as pandoc markdown citations,
--- then we don't want to include a bibliography.
-maybeRemoveBiblio :: WriterOptions -> Pandoc -> Pandoc
-maybeRemoveBiblio opts (Pandoc meta bs) = Pandoc meta bs'
-  where bs' = if isEnabled Ext_citations opts
-                 then takeWhile
-                       (/= RawBlock "pandoc" "references") bs
-                 else bs
+    where document' = plainify document
 
 plainify :: Pandoc -> Pandoc
 plainify = bottomUp go
@@ -653,7 +643,7 @@ inlineToMarkdown opts (LineBreak)
   | isEnabled Ext_escaped_line_breaks opts = return $ "\\" <> cr
   | otherwise                              = return $ "  " <> cr
 inlineToMarkdown _ Space = return space
-inlineToMarkdown opts (Cite (c:cs) lst)
+inlineToMarkdown opts (Cite (c:cs) lst@[RawInline "latex" _])
   | not (isEnabled Ext_citations opts) = inlineListToMarkdown opts lst
   | citationMode c == AuthorInText = do
     suffs <- inlineListToMarkdown opts $ citationSuffix c
@@ -680,7 +670,7 @@ inlineToMarkdown opts (Cite (c:cs) lst)
            return $ pdoc <+> r
         modekey SuppressAuthor = "-"
         modekey _              = ""
-inlineToMarkdown _ (Cite _ _) = return $ text ""
+inlineToMarkdown opts (Cite _ lst) = inlineListToMarkdown opts lst
 inlineToMarkdown opts (Link txt (src, tit)) = do
   linktext <- inlineListToMarkdown opts txt
   let linktitle = if null tit

tests/Tests/Old.hs

@@ -186,7 +186,7 @@ markdownCitationTests
      ++ [test "natbib" wopts "markdown-citations.txt"
          "markdown-citations.txt"]
   where
-    ropts             = ["-r", "markdown", "-w", "markdown-citations", "--bibliography",
+    ropts             = ["-r", "markdown", "-w", "markdown", "--bibliography",
                          "biblio.bib", "--no-wrap"]
     wopts             = ["-r", "markdown", "-w", "markdown", "--no-wrap", "--natbib"]
     styleToTest style = test style (ropts ++ ["--csl", style ++ ".csl"])