unused: Fix crash when file names contain invalid utf8.

Was decoding the git-cat-file of the symlink target as utf8, but that can't
do, unix filenames are from the 70's and need this shiny disco
fileSystemEncoding.

Command/Unused.hs

@@ -10,8 +10,7 @@
 module Command.Unused where
 
 import qualified Data.Set as S
-import qualified Data.Text.Lazy as L
-import qualified Data.Text.Lazy.Encoding as L
+import qualified Data.ByteString.Lazy as L
 import Data.BloomFilter
 import Data.BloomFilter.Easy
 import Data.BloomFilter.Hash
@@ -265,8 +264,9 @@ withKeysReferencedInGitRef a ref = do
 		go [] = noop
 		go (l:ls)
 			| isSymLink (LsTree.mode l) = do
-				content <- L.decodeUtf8 <$> catFile ref (LsTree.file l)
-				case fileKey (takeFileName $ L.unpack content) of
+				content <- encodeW8 . L.unpack
+					<$> catFile ref (LsTree.file l)
+				case fileKey (takeFileName content) of
 					Nothing -> go ls
 					Just k -> do
 						a k

debian/changelog

@@ -4,6 +4,7 @@ git-annex (3.20120616) UNRELEASED; urgency=low
     files and automatically annexes new files, etc, so you don't need
     to manually run git commands when manipulating files.
   * Enable diskfree on kfreebsd, using statvfs.
+  * unused: Fix crash when key names contain invalid utf8.
 
  -- Joey Hess <joeyh@debian.org>  Tue, 12 Jun 2012 11:35:59 -0400