Treat escaped \] better in definition lists (#717)

This fixes #546.

1 files changed, 14 insertions, 1 deletions

diff --git a/haddock-library/src/Documentation/Haddock/Parser.hs b/haddock-library/src/Documentation/Haddock/Parser.hs
index 8dc2a801..dd1044cb 100644
--- a/haddock-library/src/Documentation/Haddock/Parser.hs
+++ b/haddock-library/src/Documentation/Haddock/Parser.hs
@@ -338,7 +338,7 @@ definitionList :: BS.ByteString -> Parser (DocH mod Identifier)
 definitionList indent = DocDefList <$> p
   where
     p = do
-      label <- "[" *> (parseStringBS <$> takeWhile1 (notInClass "]\n")) <* ("]" <* optional ":")
+      label <- "[" *> (parseStringBS <$> scan False accept) <* ("]" <* optional ":")
       c <- takeLine
       (cs, items) <- more indent p
       let contents = parseString . dropNLs . unlines $ c : cs
@@ -346,6 +346,19 @@ definitionList indent = DocDefList <$> p
         Left x -> [(label, contents `docAppend` x)]
         Right i -> (label, contents) : i
 
+    -- handle '\]' escapes
+    accept True ']'  = Just False
+
+    -- stop on ']' or '\n'
+    accept _    ']'  = Nothing
+    accept _    '\n' = Nothing
+
+    -- starting an escape sequence
+    accept _    '\\' = Just True
+
+    -- anything else
+    accept _    _    = Just False
+
 -- | Drops all trailing newlines.
 dropNLs :: String -> String
 dropNLs = reverse . dropWhile (== '\n') . reverse