Use `table-of-contents` for contents of toc, make `toc` a boolean.

Changed markdown, rtf, and HTML-based templates accordingly.

This allows you to set `toc: true` in the metadata; this
previously produced strange results in some output formats.

Closes #2872.

For backwards compatibility, `toc` is still set to the
toc contents.  But it is recommended that you update templates
to use `table-of-contents` for the toc contents and `toc`
for a boolean flag.

3 files changed, 18 insertions, 6 deletions

diff --git a/src/Text/Pandoc/Writers/HTML.hs b/src/Text/Pandoc/Writers/HTML.hs
index 45c878781..451123a6d 100644
--- a/src/Text/Pandoc/Writers/HTML.hs
+++ b/src/Text/Pandoc/Writers/HTML.hs
@@ -241,7 +241,7 @@ pandocToHtml opts (Pandoc meta blocks) = do
                  then blocks
                  else prepSlides slideLevel blocks
   toc <- if writerTableOfContents opts && slideVariant /= S5Slides
-            then tableOfContents opts sects
+            then fmap renderHtml' <$> tableOfContents opts sects
             else return Nothing
   blocks' <- liftM (mconcat . intersperse (nl opts)) $
                  mapM (elementToHtml slideLevel opts) sects
@@ -292,7 +292,11 @@ pandocToHtml opts (Pandoc meta blocks) = do
                             MathJax _ -> True
                             _         -> False) $
                   defField "quotes" (stQuotes st) $
-                  maybe id (defField "toc" . renderHtml') toc $
+                  -- for backwards compatibility we populate toc
+                  -- with the contents of the toc, rather than a
+                  -- boolean:
+                  maybe id (defField "toc") toc $
+                  maybe id (defField "table-of-contents") toc $
                   defField "author-meta" authsMeta $
                   maybe id (defField "date-meta") (normalizeDate dateMeta) $
                   defField "pagetitle" (stringifyHTML (docTitle meta)) $
diff --git a/src/Text/Pandoc/Writers/Markdown.hs b/src/Text/Pandoc/Writers/Markdown.hs
index 6c7e662bf..b951288bc 100644
--- a/src/Text/Pandoc/Writers/Markdown.hs
+++ b/src/Text/Pandoc/Writers/Markdown.hs
@@ -209,8 +209,8 @@ pandocToMarkdown opts (Pandoc meta blocks) = do
                         Nothing -> empty
   let headerBlocks = filter isHeaderBlock blocks
   toc <- if writerTableOfContents opts
-         then tableOfContents opts headerBlocks
-         else return empty
+         then render' <$> tableOfContents opts headerBlocks
+         else return ""
   -- Strip off final 'references' header if markdown citations enabled
   let blocks' = if isEnabled Ext_citations opts
                    then case reverse blocks of
@@ -220,7 +220,11 @@ pandocToMarkdown opts (Pandoc meta blocks) = do
   body <- blockListToMarkdown opts blocks'
   notesAndRefs' <- notesAndRefs opts
   let main = render' $ body <> notesAndRefs'
-  let context  = defField "toc" (render' toc)
+  let context  = -- for backwards compatibility we populate toc
+                 -- with the contents of the toc, rather than a
+                 -- boolean:
+                 defField "toc" toc
+               $ defField "table-of-contents" toc
                $ defField "body" main
                $ (if isNullMeta meta
                      then id
diff --git a/src/Text/Pandoc/Writers/RTF.hs b/src/Text/Pandoc/Writers/RTF.hs
index 6666f6549..48d31c7bf 100644
--- a/src/Text/Pandoc/Writers/RTF.hs
+++ b/src/Text/Pandoc/Writers/RTF.hs
@@ -122,7 +122,11 @@ writeRTF options doc = do
   let context = defField "body" body
               $ defField "spacer" spacer
               $ (if writerTableOfContents options
-                    then defField "toc" toc
+                    then defField "table-of-contents" toc
+                         -- for backwards compatibility,
+                         -- we populate toc with the contents
+                         -- of the toc rather than a boolean:
+                         . defField "toc" toc
                     else id)
               $ metadata
   T.pack <$>