Docx reader: key list numbering off abstractNumId.

Word represents "restart numbering" on a style-based list by pointing
only the first item of the restarted list at a new `numId` that shares the
original list's abstract numbering definition but carries a
`w:startOverride`; the remaining items keep using the original `numId`.

Pandoc keyed list continuation and grouping on the `numId`, so the
restarted items continued the stale count from the earlier list (and
were split into a separate ordered list with the wrong start).

Key continuation and grouping off the `abstractNumId` instead (the real
running counter in Word), and treat `startOverride` as a restart that
resets the count.

Closes #8367.

Co-Authored-By: Claude <noreply@anthropic.com>

src/Text/Pandoc/Readers/Docx.hs

@@ -782,15 +782,16 @@ bodyPartToBlocks (Paragraph pPr parparts) = do
       then (<> horizontalRule)
       else id)
     <$> getMainPar
-bodyPartToBlocks (ListItem pPr numId lvl (Just levelInfo) parparts) = do
-  -- We check whether this current numId has previously been used,
-  -- since Docx expects us to pick up where we left off.
+bodyPartToBlocks (ListItem pPr numId lvl isRestart (Just levelInfo) parparts) = do
+  -- We check whether this current abstract numbering id has previously been
+  -- used, since Docx expects us to pick up where we left off -- unless this
+  -- item explicitly restarts numbering (see #8367).
   listState <- gets docxListState
   let startFromState = M.lookup (numId, lvl) listState
       Level _ fmt txt startFromLevelInfo = levelInfo
       start = case startFromState of
-        Just n -> n + 1
-        Nothing -> fromMaybe 1 startFromLevelInfo
+        Just n | not isRestart -> n + 1
+        _ -> fromMaybe 1 startFromLevelInfo
       kvs = [ ("level", lvl)
             , ("num-id", numId)
             , ("format", fmt)
@@ -804,7 +805,7 @@ bodyPartToBlocks (ListItem pPr numId lvl (Just levelInfo) parparts) = do
     in M.insert (numId, lvl) start (M.filterWithKey notExpired listState) }
   blks <- bodyPartToBlocks (Paragraph pPr parparts)
   return $ divWith ("", ["list-item"], kvs) blks
-bodyPartToBlocks (ListItem pPr _ _ _ parparts) =
+bodyPartToBlocks (ListItem pPr _ _ _ _ parparts) =
   let pPr' = pPr {pStyle = constructBogusParStyleData "list-paragraph": pStyle pPr}
   in
     bodyPartToBlocks $ Paragraph pPr' parparts

src/Text/Pandoc/Readers/Docx/Parse.hs

@@ -304,7 +304,7 @@ defaultParagraphStyle = ParagraphStyle { pStyle = []
 data BodyPart = Paragraph ParagraphStyle [ParPart]
               | Heading Int ParaStyleName ParagraphStyle T.Text T.Text (Maybe Level)
                  [ParPart]
-              | ListItem ParagraphStyle T.Text T.Text (Maybe Level) [ParPart]
+              | ListItem ParagraphStyle T.Text T.Text Bool (Maybe Level) [ParPart]
               | Tbl (Maybe T.Text) T.Text TblGrid TblLook [Row]
               | Captioned ParagraphStyle [ParPart] BodyPart
               | HRule
@@ -619,6 +619,28 @@ lookupLevel numId ilvl (Numbering _ numbs absNumbs) = do
     _ ->
       lookup ilvl $ map (\l@(Level i _ _ _) -> (i, l)) lvls
 
+-- | Given a @numId@ and level, return the abstract numbering id (the stable
+-- identifier shared by all numbering instances based on the same abstract
+-- numbering definition) together with a flag indicating whether this
+-- particular instance restarts numbering at this level (via a
+-- @w:startOverride@).  Word represents "restart numbering" by pointing the
+-- first item of the restarted list at a new numId that shares the abstract
+-- numbering of the original list but carries a startOverride; the remaining
+-- items keep using the original numId.  Keying list continuation off the
+-- abstract numbering id (rather than the numId) lets those items be treated
+-- as one continuous, restarted list.  See #8367.
+lookupNumberingInfo :: T.Text -> T.Text -> Numbering -> (T.Text, Bool)
+lookupNumberingInfo numId ilvl (Numbering _ numbs _) =
+  case lookup numId $
+       map (\(Numb nid absnumid ovr) -> (nid, (absnumid, ovr))) numbs of
+    Nothing -> (numId, False)
+    Just (absNumId, ovrrides) ->
+      let isRestart = case lookup ilvl $
+                           map (\lo@(LevelOverride i _ _) -> (i, lo)) ovrrides of
+                        Just (LevelOverride _ (Just _) _) -> True
+                        _ -> False
+      in (absNumId, isRestart)
+
 loElemToLevelOverride :: NameSpaces -> Element -> Maybe LevelOverride
 loElemToLevelOverride ns element
   | isElem ns "w" "lvlOverride" element = do
@@ -820,8 +842,10 @@ pNumInfo = getParStyleField numInfo . pStyle
 
 mkListItem :: ParagraphStyle -> Text -> Text -> [ParPart] -> D BodyPart
 mkListItem parstyle numId lvl parparts = do
-  lvlInfo <- lookupLevel numId lvl <$> asks envNumbering
-  return $ ListItem parstyle numId lvl lvlInfo parparts
+  numbering <- asks envNumbering
+  let lvlInfo = lookupLevel numId lvl numbering
+      (absNumId, isRestart) = lookupNumberingInfo numId lvl numbering
+  return $ ListItem parstyle absNumId lvl isRestart lvlInfo parparts
 
 pStyleIndentation :: ParagraphStyle -> Maybe ParIndentation
 pStyleIndentation style = (getParStyleField indent . pStyle) style
@@ -877,7 +901,8 @@ elemToBodyPart ns element
 elemToBodyPart ns element
   | isElem ns "w" "p" element
   , Just (numId, lvl) <- getNumInfo ns element = do
-    lvlInfo <- lookupLevel numId lvl <$> asks envNumbering
+    numbering <- asks envNumbering
+    let lvlInfo = lookupLevel numId lvl numbering
     parstyle <- elemToParagraphStyle ns element
                 <$> asks envParStyles
                 <*> asks envNumbering
@@ -885,7 +910,8 @@ elemToBodyPart ns element
     case pHeading parstyle of
       Nothing -> mkListItem parstyle numId lvl parparts
       Just (parstylename, lev)
-        -> return $ Heading lev parstylename parstyle numId lvl lvlInfo parparts
+        -> let (absNumId, _) = lookupNumberingInfo numId lvl numbering
+           in return $ Heading lev parstylename parstyle absNumId lvl lvlInfo parparts
 elemToBodyPart ns element
   | isElem ns "w" "p" element
   , [ppr] <- elChildren element
@@ -928,8 +954,10 @@ elemToBodyPart ns element
                     mkListItem parstyle numId lvl parparts
         Just (parstylename, lev) -> do
           let (numId, lvl) = fromMaybe ("","") $ pNumInfo parstyle
-          lvlInfo <- lookupLevel numId lvl <$> asks envNumbering
-          return $ Heading lev parstylename parstyle numId lvl lvlInfo parparts
+          numbering <- asks envNumbering
+          let lvlInfo = lookupLevel numId lvl numbering
+              (absNumId, _) = lookupNumberingInfo numId lvl numbering
+          return $ Heading lev parstylename parstyle absNumId lvl lvlInfo parparts
         Nothing -> return $ Paragraph parstyle parparts
 elemToBodyPart ns element
   | isElem ns "w" "tbl" element = do

test/Tests/Readers/Docx.hs

@@ -281,6 +281,10 @@ tests = [ testGroup "document"
             "sublists reset numbering to 1"
             "docx/lists_sublist_reset.docx"
             "docx/lists_sublist_reset.native"
+          , testCompare
+            "style-based list restarted on one item (#8367)"
+            "docx/lists_restart_8367.docx"
+            "docx/lists_restart_8367.native"
           , testCompare
             "definition lists"
             "docx/definition_list.docx"

test/docx/lists_restart_8367.native

@@ -0,0 +1,13 @@
+[Header 1 ("section-1",[],[]) [Str "Section",Space,Str "1"]
+,OrderedList (1,Decimal,Period)
+ [[Para [Str "Item",Space,Str "1"]]
+ ,[Para [Str "Item",Space,Str "2"]]
+ ,[Para [Str "Item",Space,Str "3"]]]
+,Para [Str "Conclusion"]
+,Header 1 ("section-2",[],[]) [Str "Section",Space,Str "2"]
+,OrderedList (1,Decimal,Period)
+ [[Para [Str "Item",Space,Str "1"]]
+ ,[Para [Str "Item",Space,Str "2"]]
+ ,[Para [Str "Item",Space,Str "3"]]
+ ,[Para [Str "Item",Space,Str "4"]]]
+,Para [Str "Conclusion"]]