HTML writer: make line breaks more consistent.

- With `--wrap=none`, we now output line breaks between
  block-level elements. Previously they were omitted
  entirely, so the whole document was on one line, unless
  there were literal line breaks in pre sections.  This makes
  the HTML writer's behavior more consistent with that of
  other writers.

- Put newline after `<dd>`.

- Put newlines after block-level elements in footnote section.

1 files changed, 59 insertions, 60 deletions

diff --git a/src/Text/Pandoc/Writers/HTML.hs b/src/Text/Pandoc/Writers/HTML.hs
index 664aeffb6..8c5548196 100644
--- a/src/Text/Pandoc/Writers/HTML.hs
+++ b/src/Text/Pandoc/Writers/HTML.hs
@@ -132,10 +132,8 @@ needsVariationSelector '↔' = True
 needsVariationSelector _   = False
 
 -- | Hard linebreak.
-nl :: WriterOptions -> Html
-nl opts = if writerWrapText opts == WrapNone
-             then mempty
-             else preEscapedString "\n"
+nl :: Html
+nl = preEscapedString "\n"
 
 -- | Convert Pandoc document to Html 5 string.
 writeHtml5String :: PandocMonad m => WriterOptions -> Pandoc -> m Text
@@ -284,7 +282,7 @@ pandocToHtml opts (Pandoc meta blocks) = do
     if null (stNotes st)
       then return mempty
       else do
-        notes <- footnoteSection opts EndOfDocument (stEmittedNotes st + 1) (reverse (stNotes st))
+        notes <- footnoteSection EndOfDocument (stEmittedNotes st + 1) (reverse (stNotes st))
         modify (\st' -> st'{ stNotes = mempty, stEmittedNotes = stEmittedNotes st' + length (stNotes st') })
         return notes
   st <- get
@@ -303,7 +301,7 @@ pandocToHtml opts (Pandoc meta blocks) = do
         KaTeX url -> do
           H.script !
             A.src (toValue $ url <> "katex.min.js") $ mempty
-          nl opts
+          nl
           let katexFlushLeft =
                 case lookupContext "classoption" metadata of
                   Just clsops | "fleqn" `elem` (clsops :: [Doc Text]) -> "true"
@@ -323,7 +321,7 @@ pandocToHtml opts (Pandoc meta blocks) = do
             , "   });"
             , "}}});"
             ]
-          nl opts
+          nl
           H.link ! A.rel "stylesheet" !
             A.href (toValue $ url <> "katex.min.css")
 
@@ -459,15 +457,15 @@ toList listop opts items = do
 
 unordList :: PandocMonad m
           => WriterOptions -> [Html] -> StateT WriterState m Html
-unordList opts = toList H.ul opts . toListItems opts
+unordList opts = toList H.ul opts . toListItems
 
 ordList :: PandocMonad m
         => WriterOptions -> [Html] -> StateT WriterState m Html
-ordList opts = toList H.ol opts . toListItems opts
+ordList opts = toList H.ol opts . toListItems
 
 defList :: PandocMonad m
         => WriterOptions -> [Html] -> StateT WriterState m Html
-defList opts items = toList H.dl opts (items ++ [nl opts])
+defList opts items = toList H.dl opts (items ++ [nl])
 
 isTaskListItem :: [Block] -> Bool
 isTaskListItem (Plain (Str "☐":Space:_):_) = True
@@ -489,7 +487,7 @@ listItemToHtml opts bls
       let checkbox  = if checked
                       then checkbox' ! A.checked ""
                       else checkbox'
-          checkbox' = H.input ! A.type_ "checkbox" ! A.disabled "" >> nl opts
+          checkbox' = H.input ! A.type_ "checkbox" ! A.disabled "" >> nl
       isContents <- inlineListToHtml opts is
       bsContents <- blockListToHtml opts bs
       return $ constr (checkbox >> isContents) >> bsContents
@@ -513,11 +511,13 @@ tableOfContents opts sects = do
 -- | Convert list of Note blocks to a footnote <div>.
 -- Assumes notes are sorted.
 footnoteSection ::
-  PandocMonad m => WriterOptions -> ReferenceLocation -> Int -> [Html] -> StateT WriterState m Html
-footnoteSection opts refLocation startCounter notes = do
+  PandocMonad m => ReferenceLocation -> Int -> [Html] -> StateT WriterState m Html
+footnoteSection refLocation startCounter notes = do
   html5 <- gets stHtml5
   slideVariant <- gets stSlideVariant
-  let hrtag = if refLocation /= EndOfBlock then (if html5 then H5.hr else H.hr) else mempty
+  let hrtag = if refLocation /= EndOfBlock
+                 then (if html5 then H5.hr else H.hr) <> nl
+                 else mempty
   let additionalClassName = case refLocation of
         EndOfBlock -> "footnotes-end-of-block"
         EndOfDocument -> "footnotes-end-of-document"
@@ -538,17 +538,17 @@ footnoteSection opts refLocation startCounter notes = do
     if null notes
        then mempty
        else do
-         nl opts
+         nl
          container $ do
-           nl opts
+           nl
            hrtag
-           nl opts
            -- Keep the previous output exactly the same if we don't
            -- have multiple notes sections
            if startCounter == 1
-             then H.ol $ mconcat notes >> nl opts
-             else H.ol ! A.start (fromString (show startCounter)) $ mconcat notes >> nl opts
-           nl opts
+             then H.ol $ mconcat notes >> nl
+             else H.ol ! A.start (fromString (show startCounter)) $
+                         mconcat notes >> nl
+           nl
 
 -- | Parse a mailto link; return Just (name, domain) or Nothing.
 parseMailto :: Text -> Maybe (Text, Text)
@@ -715,8 +715,8 @@ figure opts attr@(_, _, attrList) txt (s,tit) = do
   img <- inlineToHtml opts (Image attr alt (s,tit))
   capt <- if null txt
              then return mempty
-             else (nl opts <>) . tocapt <$> inlineListToHtml opts txt
-  let inner = mconcat [nl opts, img, capt, nl opts]
+             else (nl <>) . tocapt <$> inlineListToHtml opts txt
+  let inner = mconcat [nl, img, capt, nl]
   return $ if html5
               then H5.figure inner
               else H.div ! A.class_ "figure" $ inner
@@ -820,32 +820,32 @@ blockToHtmlInner opts (Div (ident, "section":dclasses, dkvs)
   if titleSlide
      then do
        t <- addAttrs opts attr $
-             secttag $ nl opts <> header' <> nl opts <> titleContents <> nl opts
+             secttag $ nl <> header' <> nl <> titleContents <> nl
        -- ensure 2D nesting for revealjs, but only for one level;
        -- revealjs doesn't like more than one level of nesting
        return $
          if slideVariant == RevealJsSlides && not inSection &&
               not (null innerSecs)
-            then H5.section (nl opts <> t <> nl opts <> innerContents)
-            else t <> nl opts <> if null innerSecs
+            then H5.section (nl <> t <> nl <> innerContents)
+            else t <> nl <> if null innerSecs
                                     then mempty
-                                    else innerContents <> nl opts
+                                    else innerContents <> nl
      else if writerSectionDivs opts || slide ||
               (hident /= ident && not (T.null hident || T.null ident)) ||
               (hclasses /= dclasses) || (hkvs /= dkvs)
           then addAttrs opts attr
                $ secttag
-               $ nl opts <> header' <> nl opts <>
+               $ nl <> header' <> nl <>
                  if null innerSecs
                     then mempty
-                    else innerContents <> nl opts
+                    else innerContents <> nl
           else do
             let attr' = (ident, classes' \\ hclasses, dkvs \\ hkvs)
             t <- addAttrs opts attr' header'
             return $ t <>
                      if null innerSecs
                         then mempty
-                        else nl opts <> innerContents
+                        else nl <> innerContents
 blockToHtmlInner opts (Div attr@(ident, classes, kvs') bs) = do
   html5 <- gets stHtml5
   slideVariant <- gets stSlideVariant
@@ -883,7 +883,7 @@ blockToHtmlInner opts (Div attr@(ident, classes, kvs') bs) = do
                       -- off widths! see #4028
                       mconcat <$> mapM (blockToHtml opts) bs'
                  else blockListToHtml opts' bs'
-  let contents' = nl opts >> contents >> nl opts
+  let contents' = nl >> contents >> nl
   let (divtag, classes'') = if html5 && "section" `elem` classes'
                             then (H5.section, filter (/= "section") classes')
                             else (H.div, classes')
@@ -964,10 +964,10 @@ blockToHtmlInner opts (BlockQuote blocks) = do
                                   (DefinitionList lst)
              _                 -> do contents <- blockListToHtml opts blocks
                                      return $ H.blockquote
-                                            $ nl opts >> contents >> nl opts
+                                            $ nl >> contents >> nl
      else do
        contents <- blockListToHtml opts blocks
-       return $ H.blockquote $ nl opts >> contents >> nl opts
+       return $ H.blockquote $ nl >> contents >> nl
 blockToHtmlInner opts (Header level (ident,classes,kvs) lst) = do
   contents <- inlineListToHtml opts lst
   let secnum = fromMaybe mempty $ lookup "number" kvs
@@ -1022,10 +1022,10 @@ blockToHtmlInner opts (OrderedList (startnum, numstyle, _) lst) = do
 blockToHtmlInner opts (DefinitionList lst) = do
   contents <- mapM (\(term, defs) ->
                   do term' <- liftM H.dt $ inlineListToHtml opts term
-                     defs' <- mapM (liftM (\x -> H.dd (x >> nl opts)) .
+                     defs' <- mapM (liftM (\x -> H.dd (nl >> x >> nl)) .
                                     blockListToHtml opts) defs
-                     return $ mconcat $ nl opts : term' : nl opts :
-                                        intersperse (nl opts) defs') lst
+                     return $ mconcat $ nl : term' : nl :
+                                        intersperse (nl) defs') lst
   defList opts contents
 blockToHtmlInner opts (Table attr caption colspecs thead tbody tfoot) =
   tableToHtml opts (Ann.toTable attr caption colspecs thead tbody tfoot)
@@ -1052,7 +1052,7 @@ blockToHtml opts block = do
     then do
       notes <- if null (stNotes st)
         then return mempty
-        else footnoteSection opts (writerReferenceLocation opts) (stEmittedNotes st + 1) (reverse (stNotes st))
+        else footnoteSection (writerReferenceLocation opts) (stEmittedNotes st + 1) (reverse (stNotes st))
       modify (\st' -> st'{ stNotes = mempty, stEmittedNotes = stEmittedNotes st' + length (stNotes st') })
       return (doc <> notes)
     else return doc
@@ -1071,10 +1071,10 @@ tableToHtml opts (Ann.Table attr caption colspecs thead tbodies tfoot) = do
       cs <- blockListToHtml opts longCapt
       return $ do
         H.caption cs
-        nl opts
-  coltags <- colSpecListToHtml opts colspecs
+        nl
+  coltags <- colSpecListToHtml colspecs
   head' <- tableHeadToHtml opts thead
-  bodies <- intersperse (nl opts) <$> mapM (tableBodyToHtml opts) tbodies
+  bodies <- intersperse (nl) <$> mapM (tableBodyToHtml opts) tbodies
   foot' <- tableFootToHtml opts tfoot
   let (ident,classes,kvs) = attr
   -- When widths of columns are < 100%, we need to set width for the whole
@@ -1091,13 +1091,13 @@ tableToHtml opts (Ann.Table attr caption colspecs thead tbodies tfoot) = do
                          <> "%;"):kvs)
                 _ -> attr
   addAttrs opts attr' $ H.table $ do
-    nl opts
+    nl
     captionDoc
     coltags
     head'
     mconcat bodies
     foot'
-    nl opts
+    nl
 
 tableBodyToHtml :: PandocMonad m
                 => WriterOptions
@@ -1144,7 +1144,7 @@ tablePartToHtml opts tblpart attr rows =
     tablePartElement <- addAttrs opts attr $ tag' contents
     return $ do
       tablePartElement
-      nl opts
+      nl
   where
     isEmptyRow (Ann.HeaderRow _attr _rownum cells) = all isEmptyCell cells
     isEmptyCell (Ann.Cell _colspecs _colnum cell) =
@@ -1185,14 +1185,13 @@ rowListToHtml :: PandocMonad m
               -> [TableRow]
               -> StateT WriterState m Html
 rowListToHtml opts rows =
-  (\x -> nl opts *> mconcat x) <$>
+  (\x -> nl *> mconcat x) <$>
      mapM (tableRowToHtml opts) rows
 
 colSpecListToHtml :: PandocMonad m
-                  => WriterOptions
-                  -> [ColSpec]
+                  => [ColSpec]
                   -> StateT WriterState m Html
-colSpecListToHtml opts colspecs = do
+colSpecListToHtml colspecs = do
   html5 <- gets stHtml5
   let hasDefaultWidth (_, ColWidthDefault) = True
       hasDefaultWidth _                    = False
@@ -1206,16 +1205,16 @@ colSpecListToHtml opts colspecs = do
           ColWidth w -> if html5
                         then A.style (toValue $ "width: " <> percent w)
                         else A.width (toValue $ percent w)
-        nl opts
+        nl
 
   return $
     if all hasDefaultWidth colspecs
     then mempty
     else do
       H.colgroup $ do
-        nl opts
+        nl
         mapM_ (col . snd) colspecs
-      nl opts
+      nl
 
 tableRowToHtml :: PandocMonad m
                => WriterOptions
@@ -1234,12 +1233,12 @@ tableRowToHtml opts (TableRow tblpart attr rownum rowhead rowbody) = do
   headcells <- mapM (cellToHtml opts HeaderCell) rowhead
   bodycells <- mapM (cellToHtml opts celltype) rowbody
   rowHtml <- addAttrs opts attr' $ H.tr $ do
-    nl opts
+    nl
     mconcat headcells
     mconcat bodycells
   return $ do
     rowHtml
-    nl opts
+    nl
 
 alignmentToString :: Alignment -> Maybe Text
 alignmentToString = \case
@@ -1297,18 +1296,18 @@ tableCellToHtml opts ctype colAlign (Cell attr align rowspan colspan item) = do
               : otherAttribs
   return $ do
     tag' ! attribs $ contents
-    nl opts
+    nl
 
-toListItems :: WriterOptions -> [Html] -> [Html]
-toListItems opts items = map (toListItem opts) items ++ [nl opts]
+toListItems :: [Html] -> [Html]
+toListItems items = map toListItem items ++ [nl]
 
-toListItem :: WriterOptions -> Html -> Html
-toListItem opts item = nl opts *> H.li item
+toListItem :: Html -> Html
+toListItem item = nl *> H.li item
 
 blockListToHtml :: PandocMonad m
                 => WriterOptions -> [Block] -> StateT WriterState m Html
 blockListToHtml opts lst =
-  mconcat . intersperse (nl opts) . filter nonempty
+  mconcat . intersperse (nl) . filter nonempty
     <$> mapM (blockToHtml opts) lst
   where nonempty (Empty _) = False
         nonempty _         = True
@@ -1340,9 +1339,9 @@ inlineToHtml opts inline = do
     (Str str)      -> return $ strToHtml str
     Space          -> return $ strToHtml " "
     SoftBreak      -> return $ case writerWrapText opts of
-                                     WrapNone     -> preEscapedText " "
+                                     WrapNone     -> " "
                                      WrapAuto     -> " "
-                                     WrapPreserve -> preEscapedText "\n"
+                                     WrapPreserve -> nl
     LineBreak      -> return $ do
                         if html5 then H5.br else H.br
                         strToHtml "\n"
@@ -1607,7 +1606,7 @@ blockListToNote opts ref blocks = do
                        _ | html5  -> noteItem !
                                        customAttribute "role" "doc-endnote"
                        _          -> noteItem
-  return $ nl opts >> noteItem'
+  return $ nl >> noteItem'
 
 inDiv :: PandocMonad m=> Text -> Html -> StateT WriterState m Html
 inDiv cls x = do