tweak

Backend.hs

@@ -122,8 +122,7 @@ lookupBackendName s = fromMaybe unknown $ maybeLookupBackendName s
 	where
 		unknown = error $ "unknown backend " ++ s
 maybeLookupBackendName :: String -> Maybe (Backend Annex)
-maybeLookupBackendName s =
-	if 1 /= length matches
-		then Nothing
-		else Just $ head matches
+maybeLookupBackendName s
+	| length matches == 1 = Just $ head matches
+	| otherwise = Nothing
 	where matches = filter (\b -> s == B.name b) list

Utility/DataUnits.hs

@@ -137,8 +137,7 @@ compareSizes units abbrev old new
 {- Parses strings like "10 kilobytes" or "0.5tb". -}
 readSize :: [Unit] -> String -> Maybe ByteSize
 readSize units input
-	| null parsednum = Nothing
-	| null parsedunit = Nothing
+	| null parsednum || null parsedunit = Nothing
 	| otherwise = Just $ round $ number * fromIntegral multiplier
 	where
 		(number, rest) = head parsednum