MediaWiki reader: use `_` instead of `-` in auto-identifiers.

Partially addresses #4731.
We may not still be exactly matching mediawiki's algorithm
for identifiers.

1 files changed, 6 insertions, 1 deletions

diff --git a/src/Text/Pandoc/Readers/MediaWiki.hs b/src/Text/Pandoc/Readers/MediaWiki.hs
index c7a3bcfc7..d7f52c697 100644
--- a/src/Text/Pandoc/Readers/MediaWiki.hs
+++ b/src/Text/Pandoc/Readers/MediaWiki.hs
@@ -411,9 +411,14 @@ header = try $ do
   lev <- length <$> many1 (char '=')
   guard $ lev <= 6
   contents <- trimInlines . mconcat <$> manyTill inline (count lev $ char '=')
-  attr <- registerHeader nullAttr contents
+  attr <- modifyIdentifier <$> registerHeader nullAttr contents
   return $ B.headerWith attr lev contents
 
+-- See #4731:
+modifyIdentifier :: Attr -> Attr
+modifyIdentifier (ident,cl,kv) = (ident',cl,kv)
+  where ident' = map (\c -> if c == '-' then '_' else c) ident
+
 bulletList :: PandocMonad m => MWParser m Blocks
 bulletList = B.bulletList <$>
    (   many1 (listItem '*')