Use git-annex init --version=6 to get v6 for now

Not ready to make it default because of the direct mode upgrade needing to
all happen at once.

Command/Init.hs

@@ -10,25 +10,44 @@ module Command.Init where
 import Common.Annex
 import Command
 import Annex.Init
+import Annex.Version
 import qualified Annex.SpecialRemote
 	
 cmd :: Command
 cmd = dontCheck repoExists $
 	command "init" SectionSetup "initialize git-annex"
-		paramDesc (withParams seek)
+		paramDesc (seek <$$> optParser)
 
-seek :: CmdParams -> CommandSeek
-seek = withWords start
+data InitOptions = InitOptions
+	{ initDesc :: String
+	, initVersion :: Maybe Version
+	}
 
-start :: [String] -> CommandStart
-start ws = do
-	showStart "init" description
-	next $ perform description
-  where
-	description = unwords ws
+optParser :: CmdParamsDesc -> Parser InitOptions
+optParser desc = InitOptions
+	<$> (unwords <$> cmdParams desc)
+	<*> optional (option (str >>= parseVersion)
+		( long "version" <> metavar paramValue
+		<> help "Override default annex.version"
+		))
 
-perform :: String -> CommandPerform
-perform description = do
-	initialize $ if null description then Nothing else Just description
+parseVersion :: Monad m => String -> m Version
+parseVersion v
+	| v `elem` supportedVersions = return v
+	| otherwise = fail $ v ++ " is not a currently supported repository version"
+
+seek :: InitOptions -> CommandSeek
+seek = commandAction . start
+
+start :: InitOptions -> CommandStart
+start os = do
+	showStart "init" (initDesc os)
+	next $ perform os
+
+perform :: InitOptions -> CommandPerform
+perform os = do
+	initialize 
+		(if null (initDesc os) then Nothing else Just (initDesc os))
+		(initVersion os)
 	Annex.SpecialRemote.autoEnable
 	next $ return True