fix quickcheck failure

prop_encode_decode_roundtrip failed on "\175" in C locale.

This may be a new problem after the switch to RawFilePath, but it
already had filtering for high chars, so changed to only test ascii
chars.

Git/Filename.hs

@@ -46,8 +46,8 @@ prop_encode_decode_roundtrip s = s' ==
 	-- "\343\200\271".
 	--
 	-- This property papers over the problem, by only
-	-- testing chars < 256.
-	nohigh = filter (\c -> ord c < 256)
+	-- testing ascii
+	nohigh = filter isAscii
 	-- A String can contain a NUL, but toRawFilePath
 	-- truncates on the NUL, which is generally fine
 	-- because unix filenames cannot contain NUL.

Utility/Format.hs

@@ -15,7 +15,7 @@ module Utility.Format (
 ) where
 
 import Text.Printf (printf)
-import Data.Char (isAlphaNum, isOctDigit, isHexDigit, isSpace, chr, ord)
+import Data.Char (isAlphaNum, isOctDigit, isHexDigit, isSpace, chr, ord, isAscii)
 import Data.Maybe (fromMaybe)
 import Data.Word (Word8)
 import Data.List (isPrefixOf)
@@ -176,12 +176,12 @@ encode_c' p = concatMap echar
 {- For quickcheck. 
  -
  - Encoding and then decoding roundtrips only when
- - the string does not contain high unicode, because eg, 
- - both "\12345" and "\227\128\185" are encoded to "\343\200\271".
+ - the string is ascii because eg, both "\12345" and
+ - "\227\128\185" are encoded to "\343\200\271".
  -
- - This property papers over the problem, by only testing chars < 256.
+ - This property papers over the problem, by only testing ascii.
  -}
 prop_encode_c_decode_c_roundtrip :: String -> Bool
 prop_encode_c_decode_c_roundtrip s = s' == decode_c (encode_c s')
   where
-	s' = filter (\c -> ord c < 256) s
+	s' = filter isAscii s