factor out utility function

Annex/Content/Direct.hs

@@ -66,15 +66,10 @@ changeAssociatedFiles key transform = do
 	let files' = transform files
 	when (files /= files') $ do
 		modifyContent mapping $
-			liftIO $ viaTmp write mapping $ unlines files'
+			liftIO $ viaTmp writeFileAnyEncoding mapping $
+				unlines files'
 	top <- fromRepo Git.repoPath
 	return $ map (top </>) files'
-  where
-	write file content = do
-		h <- openFile file WriteMode
-		fileEncoding h
- 		hPutStr h content
-		hClose h
 
 {- Removes the list of associated files. -}
 removeAssociatedFiles :: Key -> Annex ()

Utility/Misc.hs

@@ -40,6 +40,13 @@ readFileStrictAnyEncoding f = withFile f ReadMode $ \h -> do
 	fileEncoding h
 	hClose h `after` hGetContentsStrict h
 
+{- Writes a file, using the FileSystemEncoding so it will never crash
+ - on a badly encoded content string. -}
+writeFileAnyEncoding :: FilePath -> String -> IO ()
+writeFileAnyEncoding f content = withFile f WriteMode $ \h -> do
+	fileEncoding h
+	hPutStr h content
+
 {- Like break, but the item matching the condition is not included
  - in the second result list.
  -