factor out nukeFile

Annex/Content.hs

@@ -168,7 +168,7 @@ withTmp :: Key -> (FilePath -> Annex a) -> Annex a
 withTmp key action = do
 	tmp <- prepTmp key
 	res <- action tmp
-	liftIO $ whenM (doesFileExist tmp) $ liftIO $ removeFile tmp
+	liftIO $ nukeFile tmp
 	return res
 
 {- Checks that there is disk space available to store a given key,

Command/Add.hs

@@ -57,13 +57,10 @@ lockDown file = do
 	createAnnexDirectory tmp
 	pid <- liftIO getProcessID
 	let tmpfile = tmp </> "add" ++ show pid ++ "." ++ takeFileName file
-	nuke tmpfile
+	liftIO $ nukeFile tmpfile
 	liftIO $ createLink file tmpfile
 	return tmpfile
 
-nuke :: FilePath -> Annex ()
-nuke file = liftIO $ whenM (doesFileExist file) $ removeFile file
-
 {- Moves the file into the annex. -}
 ingest :: FilePath -> Annex (Maybe Key)
 ingest file = do
@@ -75,7 +72,7 @@ ingest file = do
 		go _ Nothing = return Nothing
 		go tmpfile (Just (key, _)) = do
 			handle (undo file key) $ moveAnnex key tmpfile
-			nuke file
+			liftIO $ nukeFile file
 			return $ Just key
 
 perform :: FilePath -> CommandPerform
@@ -86,7 +83,7 @@ perform file = maybe stop (\key -> next $ cleanup file key True) =<< ingest file
 undo :: FilePath -> Key -> IOException -> Annex a
 undo file key e = do
 	whenM (inAnnex key) $ do
-		nuke file
+		liftIO $ nukeFile file
 		handle tryharder $ fromAnnex key file
 		logStatus key InfoMissing
 	throw e

Command/DropUnused.hs

@@ -40,5 +40,5 @@ perform key = maybe droplocal dropremote =<< Remote.byName =<< from
 performOther :: (Key -> Git.Repo -> FilePath) -> Key -> CommandPerform
 performOther filespec key = do
 	f <- fromRepo $ filespec key
-	liftIO $ whenM (doesFileExist f) $ removeFile f
+	liftIO $ nukeFile f
 	next $ return True

Utility/Directory.hs

@@ -88,6 +88,13 @@ moveFile src dest = tryIO (rename src dest) >>= onrename
 				(Left _) -> return False
 				(Right s) -> return $ isDirectory s
 
+{- Removes a file, which may or may not exist.
+ -
+ - Note that an exception is thrown if the file exists but
+ - cannot be removed. -}
+nukeFile :: FilePath -> IO ()
+nukeFile file = whenM (doesFileExist file) $ removeFile file
+
 {- Runs an action in another directory. -}
 bracketCd :: FilePath -> IO a -> IO a
 bracketCd dir a = go =<< getCurrentDirectory

git-union-merge.hs

@@ -28,7 +28,7 @@ setup :: Git.Repo -> IO ()
 setup = cleanup -- idempotency
 
 cleanup :: Git.Repo -> IO ()
-cleanup g = whenM (doesFileExist $ tmpIndex g) $ removeFile $ tmpIndex g
+cleanup g = nukeFile $ tmpIndex g
 
 parseArgs :: IO [String]
 parseArgs = do