1 files changed, 32 insertions, 5 deletions
diff --git a/Backend/SHA1.hs b/Backend/SHA1.hs
index 5a232ec1d..8852e72e9 100644
--- a/Backend/SHA1.hs
+++ b/Backend/SHA1.hs
@@ -11,24 +11,51 @@ import Control.Monad.State
 import Data.String.Utils
 import System.Cmd.Utils
 import System.IO
+import System.Directory
 
 import qualified Backend.File
 import TypeInternals
 import Messages
+import qualified Annex
+import Locations
+import Core
 
 backend :: Backend
 backend = Backend.File.backend {
 	name = "SHA1",
-	getKey = keyValue
+	getKey = keyValue,
+	fsckKey = Backend.File.checkKey checkKeySHA1
 }
 
--- checksum the file to get its key
-keyValue :: FilePath -> Annex (Maybe Key)
-keyValue file = do
+sha1 :: FilePath -> Annex String
+sha1 file = do
 	showNote "checksum..."
 	liftIO $ pOpen ReadFromPipe "sha1sum" [file] $ \h -> do
 		line <- hGetLine h
 		let bits = split " " line
 		if (null bits)
 			then error "sha1sum parse error"
-			else return $ Just $ Key ((name backend), bits !! 0)
+			else return $ bits !! 0
+
+-- A key is a sha1 of its contents.
+keyValue :: FilePath -> Annex (Maybe Key)
+keyValue file = do
+	s <- sha1 file	
+	return $ Just  $ Key ((name backend), s)
+
+-- A key's sha1 is checked during fsck.
+checkKeySHA1 :: Key -> Annex Bool
+checkKeySHA1 key = do
+	g <- Annex.gitRepo
+	let file = annexLocation g key
+	present <- liftIO $ doesFileExist file
+	if (not present)
+		then return True
+		else do
+			s <- sha1 file
+			if (s == keyName key)
+				then return True
+				else do
+					dest <- moveBad key
+					showNote $ "bad file content (moved to "++dest++")"
+					return False