convert TopFilePath to use RawFilePath

Adds a dependency on filepath-bytestring, an as yet unreleased fork of
filepath that operates on RawFilePath.

Git.Repo also changed to use RawFilePath for the path to the repo.

This does eliminate some RawFilePath -> FilePath -> RawFilePath
conversions. And filepath-bytestring's </> is probably faster.
But I don't expect a major performance improvement from this.
This is mostly groundwork for making Annex.Location use RawFilePath,
which will allow for a conversion-free pipleline.

Git.hs

@@ -51,35 +51,35 @@ import Utility.FileMode
 repoDescribe :: Repo -> String
 repoDescribe Repo { remoteName = Just name } = name
 repoDescribe Repo { location = Url url } = show url
-repoDescribe Repo { location = Local { worktree = Just dir } } = dir
-repoDescribe Repo { location = Local { gitdir = dir } } = dir
-repoDescribe Repo { location = LocalUnknown dir } = dir
+repoDescribe Repo { location = Local { worktree = Just dir } } = fromRawFilePath dir
+repoDescribe Repo { location = Local { gitdir = dir } } = fromRawFilePath dir
+repoDescribe Repo { location = LocalUnknown dir } = fromRawFilePath dir
 repoDescribe Repo { location = Unknown } = "UNKNOWN"
 
 {- Location of the repo, either as a path or url. -}
 repoLocation :: Repo -> String
 repoLocation Repo { location = Url url } = show url
-repoLocation Repo { location = Local { worktree = Just dir } } = dir
-repoLocation Repo { location = Local { gitdir = dir } } = dir
-repoLocation Repo { location = LocalUnknown dir } = dir
+repoLocation Repo { location = Local { worktree = Just dir } } = fromRawFilePath dir
+repoLocation Repo { location = Local { gitdir = dir } } = fromRawFilePath dir
+repoLocation Repo { location = LocalUnknown dir } = fromRawFilePath dir
 repoLocation Repo { location = Unknown } = error "unknown repoLocation"
 
 {- Path to a repository. For non-bare, this is the worktree, for bare, 
  - it's the gitdir, and for URL repositories, is the path on the remote
  - host. -}
-repoPath :: Repo -> FilePath
-repoPath Repo { location = Url u } = unEscapeString $ uriPath u
+repoPath :: Repo -> RawFilePath
+repoPath Repo { location = Url u } = toRawFilePath $ unEscapeString $ uriPath u
 repoPath Repo { location = Local { worktree = Just d } } = d
 repoPath Repo { location = Local { gitdir = d } } = d
 repoPath Repo { location = LocalUnknown dir } = dir
 repoPath Repo { location = Unknown } = error "unknown repoPath"
 
-repoWorkTree :: Repo -> Maybe FilePath
+repoWorkTree :: Repo -> Maybe RawFilePath
 repoWorkTree Repo { location = Local { worktree = Just d } } = Just d
 repoWorkTree _ = Nothing
 
 {- Path to a local repository's .git directory. -}
-localGitDir :: Repo -> FilePath
+localGitDir :: Repo -> RawFilePath
 localGitDir Repo { location = Local { gitdir = d } } = d
 localGitDir _ = error "unknown localGitDir"
 
@@ -132,16 +132,17 @@ assertLocal repo action
 attributes :: Repo -> FilePath
 attributes repo
 	| repoIsLocalBare repo = attributesLocal repo
-	| otherwise = repoPath repo </> ".gitattributes"
+	| otherwise = fromRawFilePath (repoPath repo) </> ".gitattributes"
 
 attributesLocal :: Repo -> FilePath
-attributesLocal repo = localGitDir repo </> "info" </> "attributes"
+attributesLocal repo = fromRawFilePath (localGitDir repo)
+	</> "info" </> "attributes"
 
 {- Path to a given hook script in a repository, only if the hook exists
  - and is executable. -}
 hookPath :: String -> Repo -> IO (Maybe FilePath)
 hookPath script repo = do
-	let hook = localGitDir repo </> "hooks" </> script
+	let hook = fromRawFilePath (localGitDir repo) </> "hooks" </> script
 	ifM (catchBoolIO $ isexecutable hook)
 		( return $ Just hook , return Nothing )
   where
@@ -157,22 +158,22 @@ relPath = adjustPath torel
   where
 	torel p = do
 		p' <- relPathCwdToFile p
-		if null p'
-			then return "."
-			else return p'
+		return $ if null p' then "." else p'
 
 {- Adusts the path to a local Repo using the provided function. -}
 adjustPath :: (FilePath -> IO FilePath) -> Repo -> IO Repo
 adjustPath f r@(Repo { location = l@(Local { gitdir = d, worktree = w }) }) = do
-	d' <- f d
-	w' <- maybe (pure Nothing) (Just <$$> f) w
+	d' <- f' d
+	w' <- maybe (pure Nothing) (Just <$$> f') w
 	return $ r 
 		{ location = l 
 			{ gitdir = d'
 			, worktree = w'
 			}
 		}
+  where
+	f' v = toRawFilePath <$> f (fromRawFilePath v)
 adjustPath f r@(Repo { location = LocalUnknown d }) = do
-	d' <- f d
+	d' <- toRawFilePath <$> f (fromRawFilePath d)
 	return $ r { location = LocalUnknown d' }
 adjustPath _ r = pure r