3 files changed, 38 insertions, 18 deletions
diff --git a/Backend/URL.hs b/Backend/URL.hs
index ace578a24..a8161c98d 100644
--- a/Backend/URL.hs
+++ b/Backend/URL.hs
@@ -10,11 +10,10 @@ module Backend.URL (
 	fromUrl
 ) where
 
-import Data.Hash.MD5
-
 import Common.Annex
 import Types.Backend
 import Types.Key
+import Backend.Utilities
 
 backends :: [Backend]
 backends = [backend]
@@ -27,18 +26,12 @@ backend = Backend
 	, canUpgradeKey = Nothing
 	}
 
-{- When it's not too long, use the full url as the key name.
- - If the url is too long, it's truncated at half the filename length
- - limit, and the md5 of the url is prepended to ensure a unique key. -}
+{- Every unique url has a corresponding key. -}
 fromUrl :: String -> Maybe Integer -> Annex Key
 fromUrl url size = do
-	limit <- liftIO . fileNameLengthLimit =<< fromRepo gitAnnexDir
-	let truncurl = truncateFilePath (limit `div` 2) url
-	let key = if url == truncurl
-		then url
-		else truncurl ++ "-" ++ md5s (Str url)
+	n <- genKeyName url
 	return $ stubKey
-		{ keyName = key
+		{ keyName = n
 		, keyBackendName = "URL"
 		, keySize = size
-	}
+		}
diff --git a/Backend/Utilities.hs b/Backend/Utilities.hs
new file mode 100644
index 000000000..24dbfd6d9
--- /dev/null
+++ b/Backend/Utilities.hs
@@ -0,0 +1,25 @@
+{- git-annex backend utilities
+ -
+ - Copyright 2012 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Backend.Utilities where
+
+import Data.Hash.MD5
+
+import Common.Annex
+
+{- Generates a keyName from an input string. Takes care of sanitizing it.
+ - If it's not too long, the full string is used as the keyName.
+ - Otherwise, it's truncated at half the filename length limit, and its
+ - md5 is prepended to ensure a unique key. -}
+genKeyName :: String -> Annex String
+genKeyName s = do
+	limit <- liftIO . fileNameLengthLimit =<< fromRepo gitAnnexDir
+	let s' = preSanitizeKeyName s
+	let truncs = truncateFilePath (limit `div` 2) s'
+	return $ if s' == truncs
+		then s'
+		else truncs ++ "-" ++ md5s (Str s)
diff --git a/Backend/WORM.hs b/Backend/WORM.hs
index 3471eedc1..60db42f56 100644
--- a/Backend/WORM.hs
+++ b/Backend/WORM.hs
@@ -11,6 +11,7 @@ import Common.Annex
 import Types.Backend
 import Types.Key
 import Types.KeySource
+import Backend.Utilities
 
 backends :: [Backend]
 backends = [backend]
@@ -33,9 +34,10 @@ backend = Backend
 keyValue :: KeySource -> Annex (Maybe Key)
 keyValue source = do
 	stat <- liftIO $ getFileStatus $ contentLocation source
-	return $ Just Key {
-		keyName = takeFileName $ keyFilename source,
-		keyBackendName = name backend,
-		keySize = Just $ fromIntegral $ fileSize stat,
-		keyMtime = Just $ modificationTime stat
-	}
+	n <- genKeyName $ keyFilename source
+	return $ Just Key
+		{ keyName = n
+		, keyBackendName = name backend
+		, keySize = Just $ fromIntegral $ fileSize stat
+		, keyMtime = Just $ modificationTime stat
+		}