recognise differently-named shaN programs

Backend/SHA.hs

@@ -35,7 +35,7 @@ backends = catMaybes $ map genBackend [1, 256, 512, 224, 384]
 
 genBackend :: SHASize -> Maybe (Backend Annex)
 genBackend size
-	| supported size = Just b 
+	| shaCommand size /= "" = Just b
 	| otherwise = Nothing
 	where
 		b = Backend.File.backend 
@@ -43,12 +43,14 @@ genBackend size
 			, getKey = keyValue size
 			, fsckKey = Backend.File.checkKey $ checkKeyChecksum size
 			}
-		supported 1 = SysConfig.sha1sum
-		supported 256 = SysConfig.sha256sum
-		supported 224 = SysConfig.sha224sum
-		supported 384 = SysConfig.sha384sum
-		supported 512 = SysConfig.sha512sum
-		supported _ = False
+
+shaCommand :: SHASize -> String
+shaCommand 1 = SysConfig.sha1
+shaCommand 256 = SysConfig.sha256
+shaCommand 224 = SysConfig.sha224
+shaCommand 384 = SysConfig.sha384
+shaCommand 512 = SysConfig.sha512
+shaCommand _ = ""
 
 shaName :: SHASize -> String
 shaName size = "SHA" ++ show size
@@ -63,7 +65,7 @@ shaN size file = do
 			then error $ command ++ " parse error"
 			else return $ head bits
 	where
-		command = "sha" ++ (show size) ++ "sum"
+		command = shaCommand size
 
 {- A key is a checksum of its contents. -}
 keyValue :: SHASize -> FilePath -> Annex (Maybe Key)

TestConfig.hs

@@ -72,13 +72,25 @@ selectCmd k cmds = search cmds
 	where
 		search [] = do
 			testEnd $ Config k (BoolConfig False)
-			error $ "* need one of these commands, but none are available: " ++ show cmds
+			error $ "* need one of these commands, but none are available: " ++ show (map (head . words) cmds)
 		search (c:cs) = do
 			ret <- system $ quiet c
 			if (ret == ExitSuccess)
 				then return $ Config k (StringConfig c)
 				else search cs
 
+whichCmd :: ConfigKey -> [String] -> Test
+whichCmd k cmds = search cmds
+	where
+		search [] = do
+			testEnd $ Config k (StringConfig "")
+			return $ Config k (StringConfig "")
+		search (c:cs) = do
+			ret <- system $ quiet c
+			if (ret == ExitSuccess)
+				then return $ Config k (StringConfig $ head $ words c)
+				else search cs
+
 quiet :: String -> String
 quiet s = s ++ " >/dev/null 2>&1"
 

configure.hs

@@ -20,10 +20,11 @@ tests = [
 
 shaTestCases :: [Int] -> [TestCase]
 shaTestCases l = map make l
-	where
-		make n = 
-			let cmd = "sha" ++ show n ++ "sum"
-			in TestCase cmd $ requireCmd cmd (cmd ++ " </dev/null")
+	where make n =
+		let
+			cmds = map (\x -> "sha" ++ show n ++ x ++ " </dev/null") ["", "sum"]
+			key = "sha" ++ show n
+		in TestCase key $ whichCmd key cmds
 
 tmpDir :: String
 tmpDir = "tmp"