git-annex/Git/Filename.hs
Joey Hess 885974be99
add newtypes for QuickCheck to avoid LANG=C issues
All properties changed to use them, except for
prop_encode_c_decode_c_roundtrip, which already filtered to ascii
for other reasons.

A few modules had to be split out, because Setup does not build-depend
on QuickCheck.
2020-11-09 20:21:18 -04:00

49 lines
1.4 KiB
Haskell

{- Some git commands output encoded filenames, in a rather annoyingly complex
- C-style encoding.
-
- Copyright 2010, 2011 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
module Git.Filename where
import Common
import Utility.Format (decode_c, encode_c)
import Utility.QuickCheck
import Data.Char
import Data.Word
import qualified Data.ByteString as S
-- encoded filenames will be inside double quotes
decode :: S.ByteString -> RawFilePath
decode b = case S.uncons b of
Nothing -> b
Just (h, t)
| h /= q -> b
| otherwise -> case S.unsnoc t of
Nothing -> b
Just (i, l)
| l /= q -> b
| otherwise ->
encodeBS $ decode_c $ decodeBS i
where
q :: Word8
q = fromIntegral (ord '"')
{- Should not need to use this, except for testing decode. -}
encode :: RawFilePath -> S.ByteString
encode s = encodeBS $ "\"" ++ encode_c (decodeBS s) ++ "\""
-- 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".
--
-- That is not a real-world problem, and using TestableFilePath
-- limits what's tested to ascii, so avoids running into it.
prop_encode_decode_roundtrip :: TestableFilePath -> Bool
prop_encode_decode_roundtrip ts =
s == fromRawFilePath (decode (encode (toRawFilePath s)))
where
s = fromTestableFilePath ts