use lowercase hash by default; non-bare repos are a special case

Directory special remotes will now always store keys in the lowercase name,
which avoids the complication of catching failures to create the mixed case
name.

Git remotes using http will now try the lowercase name first.

Remote/Directory.hs

@@ -64,7 +64,7 @@ directorySetup u c = do
 
 {- Locations to try to access a given Key in the Directory. -}
 locations :: FilePath -> Key -> [FilePath]
-locations d k = map (d </>) (keyLocations k)
+locations d k = map (d </>) (keyPaths k)
 
 withCheckedFile :: (FilePath -> IO Bool) -> FilePath -> Key -> (FilePath -> IO Bool) -> IO Bool
 withCheckedFile _ [] _ _ = return False
@@ -95,18 +95,16 @@ storeEncrypted d (cipher, enck) k = do
 			return True
 
 storeHelper :: FilePath -> Key -> (FilePath -> IO Bool) -> IO Bool
-storeHelper d key a = withCheckedFile check d key go
-	where
-		check dest = isJust <$> mkdir (parentDir dest)
-		mkdir = catchMaybeIO . createDirectoryIfMissing True
-		go dest = do
-			let dir = parentDir dest
-			allowWrite dir
-			ok <- a dest
-			when ok $ do
-				preventWrite dest
-				preventWrite dir
-			return ok
+storeHelper d key a = do
+	let dest = head $ locations d key
+	let dir = parentDir dest
+	createDirectoryIfMissing True dir
+	allowWrite dir
+	ok <- a dest
+	when ok $ do
+		preventWrite dest
+		preventWrite dir
+	return ok
 
 retrieve :: FilePath -> Key -> FilePath -> Annex Bool
 retrieve d k f = liftIO $ withStoredFile d k $ \file -> copyFileExternal file f