Fix error silently discarding code ranges, make sure ByteString intervals are created with the correct byte length and decode utf16BE encoded values in single-value ranges

src/PDF/CMap.hs

@@ -14,7 +14,7 @@ import Data.Attoparsec.ByteString.Char8 (count)
 import Data.ByteString (ByteString)
 import qualified Data.ByteString as BS (length)
 import Data.ByteString.Char8.Util (
-    decodeHex, fromInt, toInt, utf16BEToutf8
+    decodeHex, toBytes, toInt, utf16BEToutf8
   )
 import Data.Map (Map, union)
 import qualified Data.Map as Map (adjust, empty, fromList, insertWith)
@@ -31,7 +31,7 @@ data CRange = CRange {
       fromSequence :: ByteString
     , toSequence :: ByteString
     , mapping :: Mapping
-  }
+  } deriving Show
 type RangeSize = Int
 type CMap = Map RangeSize [CRange]
 
@@ -53,11 +53,11 @@ cMap = fmap snd <$> runParser
 codeRanges :: Parser CMap ()
 codeRanges = do
   size <- integer <* line "begincodespacerange"
-  count size (createMapping <$> codeRange) *> return ()
+  mapM_ createMapping =<< count size codeRange
   line "endcodespacerange"
   where
     codeRange =
-      (,) <$> (stringObject <* blank) <*> (stringObject <* blank) <* EOL.parser
+      (,) <$> stringObject <* blank <*> stringObject <* EOL.parser
 
 createMapping :: (StringObject, StringObject) -> Parser CMap ()
 createMapping (Hexadecimal from, Hexadecimal to) = modify $
@@ -72,7 +72,8 @@ createMapping _ = return ()
 cMapRange :: Parser CMap ()
 cMapRange = do
   size <- integer <* line "beginbfrange"
-  mapM_ saveMapping =<< count size rangeMapping <* line "endbfrange"
+  mapM_ saveMapping =<< count size rangeMapping
+  line "endbfrange"
   where
     rangeMapping = (,,) 
       <$> (stringObject <* blank)
@@ -98,18 +99,22 @@ cMapChar = do
   saveMapping =<< count size charMapping <* line "endbfchar"
   where
     charMapping =
-      (,) <$> (stringObject <* blank) <*> (stringObject <* blank) <* EOL.parser
+      (,) <$> stringObject <* blank <*> stringObject <* EOL.parser
       >>= pairMapping
 
 between :: ByteString -> ByteString -> [ByteString]
-between from to = fromInt <$> [toInt from .. toInt to]
+between from to =
+  let size = BS.length from in
+  toBytes size <$> [toInt from .. toInt to]
 
 startFrom :: ByteString -> [ByteString]
-startFrom from = fromInt <$> [toInt from .. ]
+startFrom from =
+  let size = BS.length from in
+  toBytes size <$> [toInt from .. ]
 
 mapFromTo :: MonadParser m => (StringObject, StringObject, DirectObject) -> m [(ByteString, ByteString)]
 mapFromTo (Hexadecimal from, Hexadecimal to, StringObject (Hexadecimal dstFrom)) =
-  return $ zip (between fromBS toBS) (startFrom dstBS)
+  return $ zip (between fromBS toBS) (utf16BEToutf8 <$> startFrom dstBS)
   where
     (fromBS, toBS, dstBS) = (decodeHex from, decodeHex to, decodeHex dstFrom)