From fb0d6c7cb63a791fa72becf21ed493282e65ea91 Mon Sep 17 00:00:00 2001
From: John MacFarlane <jgm@berkeley.edu>
Date: Fri, 1 Oct 2021 15:42:00 -0700
Subject: Depend on pandoc-types 1.23, remove Null constructor on Block.

---
 src/Text/Pandoc/Writers/Man.hs | 1 -
 1 file changed, 1 deletion(-)

(limited to 'src/Text/Pandoc/Writers/Man.hs')

diff --git a/src/Text/Pandoc/Writers/Man.hs b/src/Text/Pandoc/Writers/Man.hs
index 87b2d8d21..45516ea06 100644
--- a/src/Text/Pandoc/Writers/Man.hs
+++ b/src/Text/Pandoc/Writers/Man.hs
@@ -106,7 +106,6 @@ blockToMan :: PandocMonad m
            => WriterOptions -- ^ Options
            -> Block         -- ^ Block element
            -> StateT WriterState m (Doc Text)
-blockToMan _ Null = return empty
 blockToMan opts (Div _ bs) = blockListToMan opts bs
 blockToMan opts (Plain inlines) =
   liftM vcat $ mapM (inlineListToMan opts) $ splitSentences inlines
-- 
cgit v1.2.3


From 2befeaa29f9589f81a3d6cd394d88f29089e7338 Mon Sep 17 00:00:00 2001
From: John MacFarlane <jgm@berkeley.edu>
Date: Sat, 2 Oct 2021 22:13:03 -0700
Subject: Remove splitSentences from T.P.Shared [API change].

We used to attempt automatic sentence splitting in man and ms
output, since sentence-ending periods need to be followed by
two spaces or a newline in these formats.

But it's difficult to do this reliably at the level of
`[Inline]`.
---
 src/Text/Pandoc/Shared.hs      | 28 ----------------------------
 src/Text/Pandoc/Writers/Man.hs |  5 ++---
 src/Text/Pandoc/Writers/Ms.hs  |  5 ++---
 3 files changed, 4 insertions(+), 34 deletions(-)

(limited to 'src/Text/Pandoc/Writers/Man.hs')

diff --git a/src/Text/Pandoc/Shared.hs b/src/Text/Pandoc/Shared.hs
index 7bb830d0e..6e1f29fb1 100644
--- a/src/Text/Pandoc/Shared.hs
+++ b/src/Text/Pandoc/Shared.hs
@@ -68,7 +68,6 @@ module Text.Pandoc.Shared (
                      makeMeta,
                      eastAsianLineBreakFilter,
                      htmlSpanLikeElements,
-                     splitSentences,
                      filterIpynbOutput,
                      -- * TagSoup HTML handling
                      renderTags',
@@ -709,33 +708,6 @@ eastAsianLineBreakFilter = bottomUp go
 htmlSpanLikeElements :: Set.Set T.Text
 htmlSpanLikeElements = Set.fromList ["kbd", "mark", "dfn"]
 
--- | Returns the first sentence in a list of inlines, and the rest.
-breakSentence :: [Inline] -> ([Inline], [Inline])
-breakSentence [] = ([],[])
-breakSentence xs =
-  let isSentenceEndInline (Str ys)
-        | Just (_, c) <- T.unsnoc ys = c == '.' || c == '?'
-      isSentenceEndInline LineBreak  = True
-      isSentenceEndInline _          = False
-      (as, bs) = break isSentenceEndInline xs
-  in  case bs of
-        []             -> (as, [])
-        [c]            -> (as ++ [c], [])
-        (c:Space:cs)   -> (as ++ [c], cs)
-        (c:SoftBreak:cs) -> (as ++ [c], cs)
-        (Str ".":Str s@(T.uncons -> Just (')',_)):cs)
-          -> (as ++ [Str ".", Str s], cs)
-        (x@(Str (T.stripPrefix ".)" -> Just _)):cs) -> (as ++ [x], cs)
-        (LineBreak:x@(Str (T.uncons -> Just ('.',_))):cs) -> (as ++[LineBreak], x:cs)
-        (c:cs)         -> (as ++ [c] ++ ds, es)
-          where (ds, es) = breakSentence cs
-
--- | Split a list of inlines into sentences.
-splitSentences :: [Inline] -> [[Inline]]
-splitSentences xs =
-  let (sent, rest) = breakSentence xs
-  in  if null rest then [sent] else sent : splitSentences rest
-
 -- | Process ipynb output cells.  If mode is Nothing,
 -- remove all output.  If mode is Just format, select
 -- best output for the format.  If format is not ipynb,
diff --git a/src/Text/Pandoc/Writers/Man.hs b/src/Text/Pandoc/Writers/Man.hs
index 45516ea06..89789d3c5 100644
--- a/src/Text/Pandoc/Writers/Man.hs
+++ b/src/Text/Pandoc/Writers/Man.hs
@@ -108,10 +108,9 @@ blockToMan :: PandocMonad m
            -> StateT WriterState m (Doc Text)
 blockToMan opts (Div _ bs) = blockListToMan opts bs
 blockToMan opts (Plain inlines) =
-  liftM vcat $ mapM (inlineListToMan opts) $ splitSentences inlines
+  inlineListToMan opts inlines
 blockToMan opts (Para inlines) = do
-  contents <- liftM vcat $ mapM (inlineListToMan opts) $
-    splitSentences inlines
+  contents <- inlineListToMan opts inlines
   return $ text ".PP" $$ contents
 blockToMan opts (LineBlock lns) =
   blockToMan opts $ linesToPara lns
diff --git a/src/Text/Pandoc/Writers/Ms.hs b/src/Text/Pandoc/Writers/Ms.hs
index 055324448..719407ac1 100644
--- a/src/Text/Pandoc/Writers/Ms.hs
+++ b/src/Text/Pandoc/Writers/Ms.hs
@@ -142,7 +142,7 @@ blockToMs opts (Div (ident,cls,kvs) bs) = do
        setFirstPara
        return $ anchor $$ res
 blockToMs opts (Plain inlines) =
-  liftM vcat $ mapM (inlineListToMs' opts) $ splitSentences inlines
+  inlineListToMs' opts inlines
 blockToMs opts (Para [Image attr alt (src,_tit)])
   | let ext = takeExtension (T.unpack src) in (ext == ".ps" || ext == ".eps") = do
   let (mbW,mbH) = (inPoints opts <$> dimension Width attr,
@@ -165,8 +165,7 @@ blockToMs opts (Para [Image attr alt (src,_tit)])
 blockToMs opts (Para inlines) = do
   firstPara <- gets stFirstPara
   resetFirstPara
-  contents <- liftM vcat $ mapM (inlineListToMs' opts) $
-    splitSentences inlines
+  contents <- inlineListToMs' opts inlines
   return $ literal (if firstPara then ".LP" else ".PP") $$ contents
 blockToMs _ b@(RawBlock f str)
   | f == Format "ms" = return $ literal str
-- 
cgit v1.2.3


From 5d17020a20543a5c4864ecb81b0caa5b64c280a9 Mon Sep 17 00:00:00 2001
From: John MacFarlane <jgm@berkeley.edu>
Date: Sat, 2 Oct 2021 22:56:55 -0700
Subject: T.P.Writers.Shared: Export splitSentences as a Doc Text transform.

[API change]

Use this in man/ms.
---
 src/Text/Pandoc/Writers/Man.hs    |  4 +--
 src/Text/Pandoc/Writers/Ms.hs     |  7 +++--
 src/Text/Pandoc/Writers/Shared.hs | 66 ++++++++++++++++++++++++++++++++-------
 3 files changed, 61 insertions(+), 16 deletions(-)

(limited to 'src/Text/Pandoc/Writers/Man.hs')

diff --git a/src/Text/Pandoc/Writers/Man.hs b/src/Text/Pandoc/Writers/Man.hs
index 89789d3c5..9514a1ce7 100644
--- a/src/Text/Pandoc/Writers/Man.hs
+++ b/src/Text/Pandoc/Writers/Man.hs
@@ -108,10 +108,10 @@ blockToMan :: PandocMonad m
            -> StateT WriterState m (Doc Text)
 blockToMan opts (Div _ bs) = blockListToMan opts bs
 blockToMan opts (Plain inlines) =
-  inlineListToMan opts inlines
+  splitSentences <$> inlineListToMan opts inlines
 blockToMan opts (Para inlines) = do
   contents <- inlineListToMan opts inlines
-  return $ text ".PP" $$ contents
+  return $ text ".PP" $$ splitSentences contents
 blockToMan opts (LineBlock lns) =
   blockToMan opts $ linesToPara lns
 blockToMan _ b@(RawBlock f str)
diff --git a/src/Text/Pandoc/Writers/Ms.hs b/src/Text/Pandoc/Writers/Ms.hs
index 719407ac1..332368a67 100644
--- a/src/Text/Pandoc/Writers/Ms.hs
+++ b/src/Text/Pandoc/Writers/Ms.hs
@@ -142,7 +142,7 @@ blockToMs opts (Div (ident,cls,kvs) bs) = do
        setFirstPara
        return $ anchor $$ res
 blockToMs opts (Plain inlines) =
-  inlineListToMs' opts inlines
+  splitSentences <$> inlineListToMs' opts inlines
 blockToMs opts (Para [Image attr alt (src,_tit)])
   | let ext = takeExtension (T.unpack src) in (ext == ".ps" || ext == ".eps") = do
   let (mbW,mbH) = (inPoints opts <$> dimension Width attr,
@@ -155,7 +155,7 @@ blockToMs opts (Para [Image attr alt (src,_tit)])
                               space <>
                               doubleQuotes (literal (tshow (floor hp :: Int)))
                        _ -> empty
-  capt <- inlineListToMs' opts alt
+  capt <- splitSentences <$> inlineListToMs' opts alt
   return $ nowrap (literal ".PSPIC -C " <>
              doubleQuotes (literal (escapeStr opts src)) <>
              sizeAttrs) $$
@@ -166,7 +166,8 @@ blockToMs opts (Para inlines) = do
   firstPara <- gets stFirstPara
   resetFirstPara
   contents <- inlineListToMs' opts inlines
-  return $ literal (if firstPara then ".LP" else ".PP") $$ contents
+  return $ literal (if firstPara then ".LP" else ".PP") $$
+           splitSentences contents
 blockToMs _ b@(RawBlock f str)
   | f == Format "ms" = return $ literal str
   | otherwise        = do
diff --git a/src/Text/Pandoc/Writers/Shared.hs b/src/Text/Pandoc/Writers/Shared.hs
index 0b7c6bee0..34c4ebfba 100644
--- a/src/Text/Pandoc/Writers/Shared.hs
+++ b/src/Text/Pandoc/Writers/Shared.hs
@@ -36,6 +36,8 @@ module Text.Pandoc.Writers.Shared (
                      , toTableOfContents
                      , endsWithPlain
                      , toLegacyTable
+                     , breakable
+                     , splitSentences
                      )
 where
 import Safe (lastMay)
@@ -49,6 +51,7 @@ import Data.List.NonEmpty (NonEmpty(..), nonEmpty)
 import Data.Text.Conversions (FromText(..))
 import qualified Data.Map as M
 import qualified Data.Text as T
+import Data.Text (Text)
 import qualified Text.Pandoc.Builder as Builder
 import Text.Pandoc.Definition
 import Text.Pandoc.Options
@@ -119,13 +122,13 @@ metaValueToVal _ inlineWriter (MetaInlines is) = SimpleVal <$> inlineWriter is
 
 
 -- | Retrieve a field value from a template context.
-getField   :: FromContext a b => T.Text -> Context a -> Maybe b
+getField   :: FromContext a b => Text -> Context a -> Maybe b
 getField field (Context m) = M.lookup field m >>= fromVal
 
 -- | Set a field of a template context.  If the field already has a value,
 -- convert it into a list with the new value appended to the old value(s).
 -- This is a utility function to be used in preparing template contexts.
-setField   :: ToContext a b => T.Text -> b -> Context a -> Context a
+setField   :: ToContext a b => Text -> b -> Context a -> Context a
 setField field val (Context m) =
   Context $ M.insertWith combine field (toVal val) m
  where
@@ -135,21 +138,21 @@ setField field val (Context m) =
 -- | Reset a field of a template context.  If the field already has a
 -- value, the new value replaces it.
 -- This is a utility function to be used in preparing template contexts.
-resetField :: ToContext a b => T.Text -> b -> Context a -> Context a
+resetField :: ToContext a b => Text -> b -> Context a -> Context a
 resetField field val (Context m) =
   Context (M.insert field (toVal val) m)
 
 -- | Set a field of a template context if it currently has no value.
 -- If it has a value, do nothing.
 -- This is a utility function to be used in preparing template contexts.
-defField   :: ToContext a b => T.Text -> b -> Context a -> Context a
+defField   :: ToContext a b => Text -> b -> Context a -> Context a
 defField field val (Context m) =
   Context (M.insertWith f field (toVal val) m)
   where
     f _newval oldval = oldval
 
 -- | Get the contents of the `lang` metadata field or variable.
-getLang :: WriterOptions -> Meta -> Maybe T.Text
+getLang :: WriterOptions -> Meta -> Maybe Text
 getLang opts meta =
   case lookupContext "lang" (writerVariables opts) of
         Just s -> Just s
@@ -162,7 +165,7 @@ getLang opts meta =
                _                                 -> Nothing
 
 -- | Produce an HTML tag with the given pandoc attributes.
-tagWithAttrs :: HasChars a => T.Text -> Attr -> Doc a
+tagWithAttrs :: HasChars a => Text -> Attr -> Doc a
 tagWithAttrs tag (ident,classes,kvs) = hsep
   ["<" <> text (T.unpack tag)
   ,if T.null ident
@@ -213,7 +216,7 @@ fixDisplayMath x = x
 
 -- | Converts a Unicode character into the ASCII sequence used to
 -- represent the character in "smart" Markdown.
-unsmartify :: WriterOptions -> T.Text -> T.Text
+unsmartify :: WriterOptions -> Text -> Text
 unsmartify opts = T.concatMap $ \c -> case c of
   '\8217' -> "'"
   '\8230' -> "..."
@@ -345,7 +348,7 @@ gridTable opts blocksToDoc headless aligns widths headers rows = do
 
 -- | Retrieve the metadata value for a given @key@
 -- and convert to Bool.
-lookupMetaBool :: T.Text -> Meta -> Bool
+lookupMetaBool :: Text -> Meta -> Bool
 lookupMetaBool key meta =
   case lookupMeta key meta of
       Just (MetaBlocks _)  -> True
@@ -356,7 +359,7 @@ lookupMetaBool key meta =
 
 -- | Retrieve the metadata value for a given @key@
 -- and extract blocks.
-lookupMetaBlocks :: T.Text -> Meta -> [Block]
+lookupMetaBlocks :: Text -> Meta -> [Block]
 lookupMetaBlocks key meta =
   case lookupMeta key meta of
          Just (MetaBlocks bs)   -> bs
@@ -366,7 +369,7 @@ lookupMetaBlocks key meta =
 
 -- | Retrieve the metadata value for a given @key@
 -- and extract inlines.
-lookupMetaInlines :: T.Text -> Meta -> [Inline]
+lookupMetaInlines :: Text -> Meta -> [Inline]
 lookupMetaInlines key meta =
   case lookupMeta key meta of
          Just (MetaString s)           -> [Str s]
@@ -377,7 +380,7 @@ lookupMetaInlines key meta =
 
 -- | Retrieve the metadata value for a given @key@
 -- and convert to String.
-lookupMetaString :: T.Text -> Meta -> T.Text
+lookupMetaString :: Text -> Meta -> Text
 lookupMetaString key meta =
   case lookupMeta key meta of
          Just (MetaString s)    -> s
@@ -519,3 +522,44 @@ toLegacyTable (Caption _ cbody) specs thead tbodies tfoot
 
     getComponents (Cell _ _ (RowSpan h) (ColSpan w) body)
       = (h, w, body)
+
+-- | Create a breakable 'Doc' from a text.  Only regular spaces
+-- are break points (not tabs or nonbreaking spaces).
+breakable :: Text -> Doc Text
+breakable t
+  | T.any (== ' ') t = mconcat $ foldr go mempty (T.split (==' ') t)
+  | otherwise = Text (realLength t) t
+ where
+  go "" xs =
+   case xs of
+     BreakingSpace : _ -> xs
+     _ -> BreakingSpace : xs
+  go t' xs = Text (realLength t') t' :
+    case xs of
+      [] -> xs
+      BreakingSpace : _ -> xs
+      _ -> BreakingSpace : xs
+
+splitSentences :: Doc Text -> Doc Text
+splitSentences = go . toList
+ where
+  go [] = mempty
+  go (Text len t : BreakingSpace : xs) =
+     if isSentenceEnding t
+        then Text len t <> NewLine <> go xs
+        else Text len t <> BreakingSpace <> go xs
+  go (x:xs) = x <> go xs
+
+  toList (Concat (Concat a b) c) = toList (Concat a (Concat b c))
+  toList (Concat a b) = a : toList b
+  toList x = [x]
+
+  isSentenceEnding t =
+    case T.unsnoc t of
+      Just (t',c)
+        | c == '.' || c == '!' || c == '?' -> True
+        | c == ')' || c == ']' || c == '"' || c == '\x201D' ->
+           case T.unsnoc t' of
+             Just (_,d) -> d == '.' || d == '!' || d == '?'
+             _ -> False
+      _ -> False
-- 
cgit v1.2.3


From c636b5dd1640c1f13f21bb2828c817213455229f Mon Sep 17 00:00:00 2001
From: John MacFarlane <jgm@berkeley.edu>
Date: Tue, 12 Oct 2021 20:08:35 -0700
Subject: Revert "Depend on pandoc-types 1.23, remove Null constructor on
 Block."

This reverts commit fb0d6c7cb63a791fa72becf21ed493282e65ea91.
---
 cabal.project                                      | 2 +-
 pandoc.cabal                                       | 4 ++--
 src/Text/Pandoc/Lua/Marshaling/AST.hs              | 2 ++
 src/Text/Pandoc/Shared.hs                          | 1 +
 src/Text/Pandoc/Writers/AsciiDoc.hs                | 1 +
 src/Text/Pandoc/Writers/ConTeXt.hs                 | 1 +
 src/Text/Pandoc/Writers/Custom.hs                  | 2 ++
 src/Text/Pandoc/Writers/Docbook.hs                 | 1 +
 src/Text/Pandoc/Writers/Docx.hs                    | 1 +
 src/Text/Pandoc/Writers/DokuWiki.hs                | 2 ++
 src/Text/Pandoc/Writers/FB2.hs                     | 1 +
 src/Text/Pandoc/Writers/HTML.hs                    | 1 +
 src/Text/Pandoc/Writers/Haddock.hs                 | 1 +
 src/Text/Pandoc/Writers/ICML.hs                    | 1 +
 src/Text/Pandoc/Writers/JATS.hs                    | 1 +
 src/Text/Pandoc/Writers/Jira.hs                    | 1 +
 src/Text/Pandoc/Writers/LaTeX.hs                   | 1 +
 src/Text/Pandoc/Writers/Man.hs                     | 1 +
 src/Text/Pandoc/Writers/Markdown.hs                | 3 ++-
 src/Text/Pandoc/Writers/MediaWiki.hs               | 2 ++
 src/Text/Pandoc/Writers/Ms.hs                      | 1 +
 src/Text/Pandoc/Writers/Muse.hs                    | 1 +
 src/Text/Pandoc/Writers/OpenDocument.hs            | 1 +
 src/Text/Pandoc/Writers/Org.hs                     | 1 +
 src/Text/Pandoc/Writers/Powerpoint/Presentation.hs | 1 +
 src/Text/Pandoc/Writers/RST.hs                     | 1 +
 src/Text/Pandoc/Writers/RTF.hs                     | 1 +
 src/Text/Pandoc/Writers/TEI.hs                     | 1 +
 src/Text/Pandoc/Writers/Texinfo.hs                 | 2 ++
 src/Text/Pandoc/Writers/Textile.hs                 | 2 ++
 src/Text/Pandoc/Writers/XWiki.hs                   | 2 ++
 src/Text/Pandoc/Writers/ZimWiki.hs                 | 2 ++
 stack.yaml                                         | 4 ++--
 33 files changed, 44 insertions(+), 6 deletions(-)

(limited to 'src/Text/Pandoc/Writers/Man.hs')

diff --git a/cabal.project b/cabal.project
index 64ab70164..04b79c0a7 100644
--- a/cabal.project
+++ b/cabal.project
@@ -16,7 +16,7 @@ source-repository-package
 source-repository-package
   type: git
   location: https://github.com/jgm/pandoc-types.git
-  tag: 87711e7e60a3981da0f1cc3df9e57f1134f1b82e
+  tag: 99402a46361a3e52805935b1fbe9dfe54f852d6a
 
 source-repository-package
   type: git
diff --git a/pandoc.cabal b/pandoc.cabal
index c13c768f4..615feaccb 100644
--- a/pandoc.cabal
+++ b/pandoc.cabal
@@ -561,7 +561,7 @@ library
                  mtl                   >= 2.2      && < 2.3,
                  network               >= 2.6,
                  network-uri           >= 2.6      && < 2.8,
-                 pandoc-types          >= 1.23     && < 1.24,
+                 pandoc-types          >= 1.22     && < 1.23,
                  parsec                >= 3.1      && < 3.2,
                  process               >= 1.2.3    && < 1.7,
                  random                >= 1        && < 1.3,
@@ -847,7 +847,7 @@ test-suite test-pandoc
                   filepath          >= 1.1     && < 1.5,
                   hslua             >= 1.1     && < 1.4,
                   mtl               >= 2.2     && < 2.3,
-                  pandoc-types      >= 1.23    && < 1.24,
+                  pandoc-types      >= 1.22    && < 1.23,
                   process           >= 1.2.3   && < 1.7,
                   tasty             >= 0.11    && < 1.5,
                   tasty-golden      >= 2.3     && < 2.4,
diff --git a/src/Text/Pandoc/Lua/Marshaling/AST.hs b/src/Text/Pandoc/Lua/Marshaling/AST.hs
index a1ad2cda3..8e12d232c 100644
--- a/src/Text/Pandoc/Lua/Marshaling/AST.hs
+++ b/src/Text/Pandoc/Lua/Marshaling/AST.hs
@@ -165,6 +165,7 @@ pushBlock = \case
   LineBlock blcks          -> pushViaConstructor "LineBlock" blcks
   OrderedList lstAttr list -> pushViaConstructor "OrderedList" list
                                                  (LuaListAttributes lstAttr)
+  Null                     -> pushViaConstructor "Null"
   Para blcks               -> pushViaConstructor "Para" blcks
   Plain blcks              -> pushViaConstructor "Plain" blcks
   RawBlock f cs            -> pushViaConstructor "RawBlock" f cs
@@ -188,6 +189,7 @@ peekBlock idx = defineHowTo "get Block value" $! do
       "OrderedList"    -> (\(LuaListAttributes lstAttr, lst) ->
                              OrderedList lstAttr lst)
                           <$!> elementContent
+      "Null"           -> return Null
       "Para"           -> Para <$!> elementContent
       "Plain"          -> Plain <$!> elementContent
       "RawBlock"       -> uncurry RawBlock <$!> elementContent
diff --git a/src/Text/Pandoc/Shared.hs b/src/Text/Pandoc/Shared.hs
index 6e1f29fb1..06fd052b9 100644
--- a/src/Text/Pandoc/Shared.hs
+++ b/src/Text/Pandoc/Shared.hs
@@ -920,6 +920,7 @@ blockToInlines (Table _ _ _ (TableHead _ hbd) bodies (TableFoot _ fbd)) =
     unTableBody (TableBody _ _ hd bd) = hd <> bd
     unTableBodies = concatMap unTableBody
 blockToInlines (Div _ blks) = blocksToInlines' blks
+blockToInlines Null = mempty
 
 blocksToInlinesWithSep :: Inlines -> [Block] -> Inlines
 blocksToInlinesWithSep sep =
diff --git a/src/Text/Pandoc/Writers/AsciiDoc.hs b/src/Text/Pandoc/Writers/AsciiDoc.hs
index f0973178e..bcef4a089 100644
--- a/src/Text/Pandoc/Writers/AsciiDoc.hs
+++ b/src/Text/Pandoc/Writers/AsciiDoc.hs
@@ -140,6 +140,7 @@ blockToAsciiDoc :: PandocMonad m
                 => WriterOptions -- ^ Options
                 -> Block         -- ^ Block element
                 -> ADW m (Doc Text)
+blockToAsciiDoc _ Null = return empty
 blockToAsciiDoc opts (Div (id',"section":_,_)
                        (Header level (_,cls,kvs) ils : xs)) = do
   hdr <- blockToAsciiDoc opts (Header level (id',cls,kvs) ils)
diff --git a/src/Text/Pandoc/Writers/ConTeXt.hs b/src/Text/Pandoc/Writers/ConTeXt.hs
index 0150f7dff..3cafcefba 100644
--- a/src/Text/Pandoc/Writers/ConTeXt.hs
+++ b/src/Text/Pandoc/Writers/ConTeXt.hs
@@ -154,6 +154,7 @@ toLabel z = T.concatMap go z
 
 -- | Convert Pandoc block element to ConTeXt.
 blockToConTeXt :: PandocMonad m => Block -> WM m (Doc Text)
+blockToConTeXt Null = return empty
 blockToConTeXt (Div attr@(_,"section":_,_)
                  (Header level _ title' : xs)) = do
   header' <- sectionHeader attr level title'
diff --git a/src/Text/Pandoc/Writers/Custom.hs b/src/Text/Pandoc/Writers/Custom.hs
index d207f5093..1e9f37d2f 100644
--- a/src/Text/Pandoc/Writers/Custom.hs
+++ b/src/Text/Pandoc/Writers/Custom.hs
@@ -116,6 +116,8 @@ docToCustom opts (Pandoc (Meta metamap) blocks) = do
 blockToCustom :: Block         -- ^ Block element
               -> Lua String
 
+blockToCustom Null = return ""
+
 blockToCustom (Plain inlines) = Lua.callFunc "Plain" (Stringify inlines)
 
 blockToCustom (Para [Image attr txt (src,tit)]) =
diff --git a/src/Text/Pandoc/Writers/Docbook.hs b/src/Text/Pandoc/Writers/Docbook.hs
index 3cb68c311..33a6f5f0c 100644
--- a/src/Text/Pandoc/Writers/Docbook.hs
+++ b/src/Text/Pandoc/Writers/Docbook.hs
@@ -165,6 +165,7 @@ imageToDocbook _ attr src = selfClosingTag "imagedata" $
 
 -- | Convert a Pandoc block element to Docbook.
 blockToDocbook :: PandocMonad m => WriterOptions -> Block -> DB m (Doc Text)
+blockToDocbook _ Null = return empty
 -- Add ids to paragraphs in divs with ids - this is needed for
 -- pandoc-citeproc to get link anchors in bibliographies:
 blockToDocbook opts (Div (id',"section":_,_) (Header lvl (_,_,attrs) ils : xs)) = do
diff --git a/src/Text/Pandoc/Writers/Docx.hs b/src/Text/Pandoc/Writers/Docx.hs
index a3949792d..686a2f662 100644
--- a/src/Text/Pandoc/Writers/Docx.hs
+++ b/src/Text/Pandoc/Writers/Docx.hs
@@ -800,6 +800,7 @@ blockToOpenXML :: (PandocMonad m) => WriterOptions -> Block -> WS m [Content]
 blockToOpenXML opts blk = withDirection $ blockToOpenXML' opts blk
 
 blockToOpenXML' :: (PandocMonad m) => WriterOptions -> Block -> WS m [Content]
+blockToOpenXML' _ Null = return []
 blockToOpenXML' opts (Div (ident,_classes,kvs) bs) = do
   stylemod <- case lookup dynamicStyleKey kvs of
                    Just (fromString . T.unpack -> sty) -> do
diff --git a/src/Text/Pandoc/Writers/DokuWiki.hs b/src/Text/Pandoc/Writers/DokuWiki.hs
index 5fe64717a..602c70ebe 100644
--- a/src/Text/Pandoc/Writers/DokuWiki.hs
+++ b/src/Text/Pandoc/Writers/DokuWiki.hs
@@ -98,6 +98,8 @@ blockToDokuWiki :: PandocMonad m
                 -> Block         -- ^ Block element
                 -> DokuWiki m Text
 
+blockToDokuWiki _ Null = return ""
+
 blockToDokuWiki opts (Div _attrs bs) = do
   contents <- blockListToDokuWiki opts bs
   return $ contents <> "\n"
diff --git a/src/Text/Pandoc/Writers/FB2.hs b/src/Text/Pandoc/Writers/FB2.hs
index f393f031f..6bad37404 100644
--- a/src/Text/Pandoc/Writers/FB2.hs
+++ b/src/Text/Pandoc/Writers/FB2.hs
@@ -358,6 +358,7 @@ blockToXml (Table _ blkCapt specs thead tbody tfoot) = do
       align_str AlignCenter  = "center"
       align_str AlignRight   = "right"
       align_str AlignDefault = "left"
+blockToXml Null = return []
 
 -- Replace plain text with paragraphs and add line break after paragraphs.
 -- It is used to convert plain text from tight list items to paragraphs.
diff --git a/src/Text/Pandoc/Writers/HTML.hs b/src/Text/Pandoc/Writers/HTML.hs
index 5992c994f..8fc81ed24 100644
--- a/src/Text/Pandoc/Writers/HTML.hs
+++ b/src/Text/Pandoc/Writers/HTML.hs
@@ -730,6 +730,7 @@ adjustNumbers opts doc =
    showSecNum = T.intercalate "." . map tshow
 
 blockToHtmlInner :: PandocMonad m => WriterOptions -> Block -> StateT WriterState m Html
+blockToHtmlInner _ Null = return mempty
 blockToHtmlInner opts (Plain lst) = inlineListToHtml opts lst
 blockToHtmlInner opts (Para [Image attr@(_,classes,_) txt (src,tit)])
   | "stretch" `elem` classes = do
diff --git a/src/Text/Pandoc/Writers/Haddock.hs b/src/Text/Pandoc/Writers/Haddock.hs
index 9a61c339a..75e14714b 100644
--- a/src/Text/Pandoc/Writers/Haddock.hs
+++ b/src/Text/Pandoc/Writers/Haddock.hs
@@ -90,6 +90,7 @@ blockToHaddock :: PandocMonad m
                => WriterOptions -- ^ Options
                -> Block         -- ^ Block element
                -> StateT WriterState m (Doc Text)
+blockToHaddock _ Null = return empty
 blockToHaddock opts (Div _ ils) = do
   contents <- blockListToHaddock opts ils
   return $ contents <> blankline
diff --git a/src/Text/Pandoc/Writers/ICML.hs b/src/Text/Pandoc/Writers/ICML.hs
index 8da931406..c254fbc58 100644
--- a/src/Text/Pandoc/Writers/ICML.hs
+++ b/src/Text/Pandoc/Writers/ICML.hs
@@ -381,6 +381,7 @@ blockToICML opts style (Table _ blkCapt specs thead tbody tfoot) =
 blockToICML opts style (Div (_ident, _, kvs) lst) =
   let dynamicStyle = maybeToList $ lookup dynamicStyleKey kvs
   in  blocksToICML opts (dynamicStyle <> style) lst
+blockToICML _ _ Null = return empty
 
 -- | Convert a list of lists of blocks to ICML list items.
 listItemsToICML :: PandocMonad m => WriterOptions -> Text -> Style -> Maybe ListAttributes -> [[Block]] -> WS m (Doc Text)
diff --git a/src/Text/Pandoc/Writers/JATS.hs b/src/Text/Pandoc/Writers/JATS.hs
index f20178bd1..9db8723d1 100644
--- a/src/Text/Pandoc/Writers/JATS.hs
+++ b/src/Text/Pandoc/Writers/JATS.hs
@@ -251,6 +251,7 @@ codeAttr opts (ident,classes,kvs) = (lang, attr)
 
 -- | Convert a Pandoc block element to JATS.
 blockToJATS :: PandocMonad m => WriterOptions -> Block -> JATS m (Doc Text)
+blockToJATS _ Null = return empty
 blockToJATS opts (Div (id',"section":_,kvs) (Header _lvl _ ils : xs)) = do
   let idAttr = [ ("id", writerIdentifierPrefix opts <> escapeNCName id')
                | not (T.null id')]
diff --git a/src/Text/Pandoc/Writers/Jira.hs b/src/Text/Pandoc/Writers/Jira.hs
index 709064270..1351814e9 100644
--- a/src/Text/Pandoc/Writers/Jira.hs
+++ b/src/Text/Pandoc/Writers/Jira.hs
@@ -103,6 +103,7 @@ toJiraBlocks blocks = do
         Para xs              -> singleton . Jira.Para <$> toJiraInlines xs
         Plain xs             -> singleton . Jira.Para <$> toJiraInlines xs
         RawBlock fmt cs      -> rawBlockToJira fmt cs
+        Null                 -> return mempty
         Table _ blkCapt specs thead tbody tfoot -> singleton <$> do
           let (_, _, _, hd, body) = toLegacyTable blkCapt specs thead tbody tfoot
           headerRow <- if all null hd
diff --git a/src/Text/Pandoc/Writers/LaTeX.hs b/src/Text/Pandoc/Writers/LaTeX.hs
index 144c3d579..8c45c8db5 100644
--- a/src/Text/Pandoc/Writers/LaTeX.hs
+++ b/src/Text/Pandoc/Writers/LaTeX.hs
@@ -253,6 +253,7 @@ isListBlock _                  = False
 blockToLaTeX :: PandocMonad m
              => Block     -- ^ Block to convert
              -> LW m (Doc Text)
+blockToLaTeX Null = return empty
 blockToLaTeX (Div attr@(identifier,"block":dclasses,_)
              (Header _ _ ils : bs)) = do
   let blockname
diff --git a/src/Text/Pandoc/Writers/Man.hs b/src/Text/Pandoc/Writers/Man.hs
index 9514a1ce7..8a34bf47f 100644
--- a/src/Text/Pandoc/Writers/Man.hs
+++ b/src/Text/Pandoc/Writers/Man.hs
@@ -106,6 +106,7 @@ blockToMan :: PandocMonad m
            => WriterOptions -- ^ Options
            -> Block         -- ^ Block element
            -> StateT WriterState m (Doc Text)
+blockToMan _ Null = return empty
 blockToMan opts (Div _ bs) = blockListToMan opts bs
 blockToMan opts (Plain inlines) =
   splitSentences <$> inlineListToMan opts inlines
diff --git a/src/Text/Pandoc/Writers/Markdown.hs b/src/Text/Pandoc/Writers/Markdown.hs
index 49fb873a9..fda2bbcef 100644
--- a/src/Text/Pandoc/Writers/Markdown.hs
+++ b/src/Text/Pandoc/Writers/Markdown.hs
@@ -313,6 +313,7 @@ blockToMarkdown' :: PandocMonad m
                  => WriterOptions -- ^ Options
                  -> Block         -- ^ Block element
                  -> MD m (Doc Text)
+blockToMarkdown' _ Null = return empty
 blockToMarkdown' opts (Div attrs ils) = do
   contents <- blockListToMarkdown opts ils
   variant <- asks envVariant
@@ -811,7 +812,7 @@ blockListToMarkdown opts blocks = do
       isListBlock (DefinitionList _) = True
       isListBlock _                  = False
       commentSep
-        | variant == PlainText        = RawBlock "html" "<!-- -->\n"
+        | variant == PlainText        = Null
         | isEnabled Ext_raw_html opts = RawBlock "html" "<!-- -->\n"
         | otherwise                   = RawBlock "markdown" "&nbsp;\n"
   mconcat <$> mapM (blockToMarkdown opts) (fixBlocks blocks)
diff --git a/src/Text/Pandoc/Writers/MediaWiki.hs b/src/Text/Pandoc/Writers/MediaWiki.hs
index 899e40418..5029be69f 100644
--- a/src/Text/Pandoc/Writers/MediaWiki.hs
+++ b/src/Text/Pandoc/Writers/MediaWiki.hs
@@ -81,6 +81,8 @@ blockToMediaWiki :: PandocMonad m
                  => Block         -- ^ Block element
                  -> MediaWikiWriter m Text
 
+blockToMediaWiki Null = return ""
+
 blockToMediaWiki (Div attrs bs) = do
   contents <- blockListToMediaWiki bs
   return $ render Nothing (tagWithAttrs "div" attrs) <> "\n\n" <>
diff --git a/src/Text/Pandoc/Writers/Ms.hs b/src/Text/Pandoc/Writers/Ms.hs
index 332368a67..eeb8eca62 100644
--- a/src/Text/Pandoc/Writers/Ms.hs
+++ b/src/Text/Pandoc/Writers/Ms.hs
@@ -110,6 +110,7 @@ blockToMs :: PandocMonad m
           => WriterOptions -- ^ Options
           -> Block         -- ^ Block element
           -> MS m (Doc Text)
+blockToMs _ Null = return empty
 blockToMs opts (Div (ident,cls,kvs) bs) = do
   let anchor = if T.null ident
                   then empty
diff --git a/src/Text/Pandoc/Writers/Muse.hs b/src/Text/Pandoc/Writers/Muse.hs
index 329522a48..d5100f43f 100644
--- a/src/Text/Pandoc/Writers/Muse.hs
+++ b/src/Text/Pandoc/Writers/Muse.hs
@@ -275,6 +275,7 @@ blockToMuse (Table _ blkCapt specs thead tbody tfoot) =
               (length aligns :| length widths : map length (headers:rows))
     isSimple = onlySimpleTableCells (headers : rows) && all (== 0) widths
 blockToMuse (Div _ bs) = flatBlockListToMuse bs
+blockToMuse Null = return empty
 
 -- | Return Muse representation of notes collected so far.
 currentNotesToMuse :: PandocMonad m
diff --git a/src/Text/Pandoc/Writers/OpenDocument.hs b/src/Text/Pandoc/Writers/OpenDocument.hs
index 27473775b..5f3224c2f 100644
--- a/src/Text/Pandoc/Writers/OpenDocument.hs
+++ b/src/Text/Pandoc/Writers/OpenDocument.hs
@@ -398,6 +398,7 @@ blockToOpenDocument o = \case
     b@(RawBlock f s) -> if f == Format "opendocument"
                         then return $ text $ T.unpack s
                         else empty <$ report (BlockNotRendered b)
+    Null             -> return empty
     where
       defList       b = do setInDefinitionList True
                            r <- vcat  <$> mapM (deflistItemToOpenDocument o) b
diff --git a/src/Text/Pandoc/Writers/Org.hs b/src/Text/Pandoc/Writers/Org.hs
index aae6fe0ef..f4a22695c 100644
--- a/src/Text/Pandoc/Writers/Org.hs
+++ b/src/Text/Pandoc/Writers/Org.hs
@@ -102,6 +102,7 @@ isRawFormat f =
 blockToOrg :: PandocMonad m
            => Block         -- ^ Block element
            -> Org m (Doc Text)
+blockToOrg Null = return empty
 blockToOrg (Div attr bs) = divToOrg attr bs
 blockToOrg (Plain inlines) = inlineListToOrg inlines
 -- title beginning with fig: indicates that the image is a figure
diff --git a/src/Text/Pandoc/Writers/Powerpoint/Presentation.hs b/src/Text/Pandoc/Writers/Powerpoint/Presentation.hs
index 99b016a63..fe34d24dc 100644
--- a/src/Text/Pandoc/Writers/Powerpoint/Presentation.hs
+++ b/src/Text/Pandoc/Writers/Powerpoint/Presentation.hs
@@ -1041,6 +1041,7 @@ blockIsBlank
       HorizontalRule -> True
       Table{} -> False
       Div _ bls -> all blockIsBlank bls
+      Null -> True
 
 textIsBlank :: T.Text -> Bool
 textIsBlank = T.all isSpace
diff --git a/src/Text/Pandoc/Writers/RST.hs b/src/Text/Pandoc/Writers/RST.hs
index 88e185897..8b2002851 100644
--- a/src/Text/Pandoc/Writers/RST.hs
+++ b/src/Text/Pandoc/Writers/RST.hs
@@ -197,6 +197,7 @@ bordered contents c =
 blockToRST :: PandocMonad m
            => Block         -- ^ Block element
            -> RST m (Doc Text)
+blockToRST Null = return empty
 blockToRST (Div ("",["title"],[]) _) = return empty
   -- this is generated by the rst reader and can safely be
   -- omitted when we're generating rst
diff --git a/src/Text/Pandoc/Writers/RTF.hs b/src/Text/Pandoc/Writers/RTF.hs
index 7e3e770ba..063371ebc 100644
--- a/src/Text/Pandoc/Writers/RTF.hs
+++ b/src/Text/Pandoc/Writers/RTF.hs
@@ -229,6 +229,7 @@ blockToRTF :: PandocMonad m
            -> Alignment -- ^ alignment
            -> Block     -- ^ block to convert
            -> m Text
+blockToRTF _ _ Null = return ""
 blockToRTF indent alignment (Div _ bs) =
   blocksToRTF indent alignment bs
 blockToRTF indent alignment (Plain lst) =
diff --git a/src/Text/Pandoc/Writers/TEI.hs b/src/Text/Pandoc/Writers/TEI.hs
index e8682018b..18015259d 100644
--- a/src/Text/Pandoc/Writers/TEI.hs
+++ b/src/Text/Pandoc/Writers/TEI.hs
@@ -97,6 +97,7 @@ imageToTEI opts attr src = return $ selfClosingTag "graphic" $
 
 -- | Convert a Pandoc block element to TEI.
 blockToTEI :: PandocMonad m => WriterOptions -> Block -> m (Doc Text)
+blockToTEI _ Null = return empty
 blockToTEI opts (Div attr@(_,"section":_,_) (Header lvl _ ils : xs)) =
   do
   -- TEI doesn't allow sections with no content, so insert some if needed
diff --git a/src/Text/Pandoc/Writers/Texinfo.hs b/src/Text/Pandoc/Writers/Texinfo.hs
index f817900e5..6a33b4283 100644
--- a/src/Text/Pandoc/Writers/Texinfo.hs
+++ b/src/Text/Pandoc/Writers/Texinfo.hs
@@ -115,6 +115,8 @@ blockToTexinfo :: PandocMonad m
                => Block     -- ^ Block to convert
                -> TI m (Doc Text)
 
+blockToTexinfo Null = return empty
+
 blockToTexinfo (Div _ bs) = blockListToTexinfo bs
 
 blockToTexinfo (Plain lst) =
diff --git a/src/Text/Pandoc/Writers/Textile.hs b/src/Text/Pandoc/Writers/Textile.hs
index b1a4ed4a0..03d030477 100644
--- a/src/Text/Pandoc/Writers/Textile.hs
+++ b/src/Text/Pandoc/Writers/Textile.hs
@@ -100,6 +100,8 @@ blockToTextile :: PandocMonad m
                -> Block         -- ^ Block element
                -> TW m Text
 
+blockToTextile _ Null = return ""
+
 blockToTextile opts (Div attr bs) = do
   let startTag = render Nothing $ tagWithAttrs "div" attr
   let endTag = "</div>"
diff --git a/src/Text/Pandoc/Writers/XWiki.hs b/src/Text/Pandoc/Writers/XWiki.hs
index 0d7387eaa..c35235650 100644
--- a/src/Text/Pandoc/Writers/XWiki.hs
+++ b/src/Text/Pandoc/Writers/XWiki.hs
@@ -74,6 +74,8 @@ blockListToXWiki blocks =
 
 blockToXWiki :: PandocMonad m => Block -> XWikiReader m Text
 
+blockToXWiki Null = return ""
+
 blockToXWiki (Div (id', _, _) blocks) = do
   content <- blockListToXWiki blocks
   return $ genAnchor id' <> content
diff --git a/src/Text/Pandoc/Writers/ZimWiki.hs b/src/Text/Pandoc/Writers/ZimWiki.hs
index 651da4e46..df914f590 100644
--- a/src/Text/Pandoc/Writers/ZimWiki.hs
+++ b/src/Text/Pandoc/Writers/ZimWiki.hs
@@ -78,6 +78,8 @@ escapeText = T.replace "__" "''__''" .
 -- | Convert Pandoc block element to ZimWiki.
 blockToZimWiki :: PandocMonad m => WriterOptions -> Block -> ZW m Text
 
+blockToZimWiki _ Null = return ""
+
 blockToZimWiki opts (Div _attrs bs) = do
   contents <- blockListToZimWiki opts bs
   return $ contents <> "\n"
diff --git a/stack.yaml b/stack.yaml
index 3d99d80b5..d12ab3587 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -13,9 +13,9 @@ extra-deps:
 - emojis-0.1.2
 - doclayout-0.3.1.1
 - git: https://github.com/jgm/pandoc-types.git
-  commit: 87711e7e60a3981da0f1cc3df9e57f1134f1b82e
+  commit: 99402a46361a3e52805935b1fbe9dfe54f852d6a
 - git: https://github.com/jgm/texmath.git
-  commit: c046e6e5a93510f2c37dbc700f82a2c53ed87b5f
+  commit: 19700530733707284bb41f24add757f19ca23430
 - git: https://github.com/jgm/citeproc.git
   commit: 673a7fb643d24a3bb0f60f8f29e189c0ba7ef15b
 - git: https://github.com/jgm/commonmark-hs.git
-- 
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