use openTempFile from file-io

And follow-on changes.

Note that relatedTemplate was changed to operate on a RawFilePath, and
so when it counts the length, it is now the number of bytes, not the
number of code points. This will just make it truncate shorter strings
in some cases, the truncation is still unicode aware.

When not building with the OsPath flag, toOsPath . fromRawFilePath and
fromRawFilePath . fromOsPath do extra conversions back and forth between
String and ByteString. That overhead could be avoided, but that's the
non-optimised build mode, so didn't bother.

Sponsored-by: unqueued

Logs/File.hs

@@ -37,11 +37,11 @@ import qualified Data.ByteString.Lazy.Char8 as L8
 -- making the new file have whatever permissions the git repository is
 -- configured to use. Creates the parent directory when necessary.
 writeLogFile :: RawFilePath -> String -> Annex ()
-writeLogFile f c = createDirWhenNeeded f $ viaTmp writelog (fromRawFilePath f) c
+writeLogFile f c = createDirWhenNeeded f $ viaTmp writelog (toOsPath f) c
   where
 	writelog tmp c' = do
-		liftIO $ writeFile tmp c'
-		setAnnexFilePerm (toRawFilePath tmp)
+		liftIO $ writeFile (fromRawFilePath (fromOsPath tmp)) c'
+		setAnnexFilePerm (fromOsPath tmp)
 
 -- | Runs the action with a handle connected to a temp file.
 -- The temp file replaces the log file once the action succeeds.
@@ -77,16 +77,16 @@ appendLogFile f lck c =
 modifyLogFile :: RawFilePath -> RawFilePath -> ([L.ByteString] -> [L.ByteString]) -> Annex ()
 modifyLogFile f lck modf = withExclusiveLock lck $ do
 	ls <- liftIO $ fromMaybe []
-		<$> tryWhenExists (fileLines <$> L.readFile f')
+		<$> tryWhenExists (fileLines <$> F.readFile f')
 	let ls' = modf ls
 	when (ls' /= ls) $
 		createDirWhenNeeded f $
 			viaTmp writelog f' (L8.unlines ls')
   where
-	f' = fromRawFilePath f
+	f' = toOsPath f
 	writelog lf b = do
-		liftIO $ L.writeFile lf b
-		setAnnexFilePerm (toRawFilePath lf)
+		liftIO $ F.writeFile lf b
+		setAnnexFilePerm (fromOsPath lf)
 
 -- | Checks the content of a log file to see if any line matches.
 checkLogFile :: RawFilePath -> RawFilePath -> (L.ByteString -> Bool) -> Annex Bool