git-annex/Git/Filename.hs
Joey Hess da8e84efe9
fix failing quickcheck properties
QuickCheck 2.10 found a counterexample eg "\929184" broke the property.

As far as I can tell, Git.Filename is matching how git handles encoding
of strange high unicode characters in filenames for display. Git does
not display high unicode characters, and instead displays the C-style
escaped form of each byte. This is ambiguous, but since git is not
unicode aware, it doesn't need to roundtrip parse it.

So, making Git.FileName's roundtrip test only chars < 256 seems fine.

Utility.Format.format uses encode_c, in order to mimic git, so that's
ok.

Utility.Format.gen uses decode_c, but only so that stuff like "\n"
in the format string is handled. If the format string contains C-style
octal escapes, they will be converted to ascii characters, and not
combined into unicode characters, but that should not be a problem.
If the user wants unicode characters, they can include them in the
format string, without escaping them.

Finally, decode_c is used by Utility.Gpg.secretKeys, because gpg
--with-colons hex-escapes some characters in particular ':' and '\\'.
gpg passes unicode through, so this use of decode_c is not a problem.

This commit was sponsored by Henrik Riomar on Patreon.
2017-06-17 16:48:00 -04:00

34 lines
904 B
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 GPL version 3 or higher.
-}
module Git.Filename where
import Common
import Utility.Format (decode_c, encode_c)
import Data.Char
decode :: String -> FilePath
decode [] = []
decode f@(c:s)
-- encoded strings will be inside double quotes
| c == '"' && end s == ['"'] = decode_c $ beginning s
| otherwise = f
{- Should not need to use this, except for testing decode. -}
encode :: FilePath -> String
encode s = "\"" ++ encode_c s ++ "\""
{- For quickcheck.
-
- See comment on Utility.Format.prop_encode_c_decode_c_roundtrip for
- why this only tests chars < 256 -}
prop_encode_decode_roundtrip :: String -> Bool
prop_encode_decode_roundtrip s = s' == decode (encode s')
where
s' = filter (\c -> ord c < 256) s