info: Added --autoenable option

Use cases include using git-annex init --no-autoenable and then going back
and enabling the special remotes that have autoenable configured. As well
as just querying to remember which ones have it enabled.

It lists all special remotes that have autoenable=yes whether currently
enabled or not. And it can be used with --json.

I pondered making this "git-annex info autoenable", but that seemed wrong
because then if the use has a directory named "autoenable", it's unclear
what they are asking for. (Although "git-annex info remote" may be
similarly unclear.) Making it an option does mean that it can't be provided
via --batch though.

Sponsored-by: Dartmouth College's Datalad project

Command/Info.hs

@@ -22,6 +22,7 @@ import qualified Git
 import qualified Annex
 import qualified Remote
 import qualified Types.Remote as Remote
+import qualified Annex.SpecialRemote as SpecialRemote
 import Utility.DataUnits
 import Utility.DiskFree
 import Annex.Content
@@ -105,6 +106,7 @@ data InfoOptions = InfoOptions
 	{ infoFor :: CmdParams
 	, bytesOption :: Bool
 	, batchOption :: BatchMode
+	, autoenableOption :: Bool
 	}
 
 optParser :: CmdParamsDesc -> Parser InfoOptions
@@ -115,6 +117,10 @@ optParser desc = InfoOptions
 		<> help "display file sizes in bytes"
 		)
 	<*> parseBatchOption False
+	<*> switch
+		( long "autoenable"
+		<> help "list special remotes that are configured to autoenable"
+		)
 
 seek :: InfoOptions -> CommandSeek
 seek o = case batchOption o of
@@ -124,7 +130,9 @@ seek o = case batchOption o of
 
 start :: InfoOptions -> [String] -> CommandStart
 start o [] = do
-	globalInfo o
+	if autoenableOption o
+		then autoenableInfo
+		else globalInfo o
 	stop
 start o ps = do
 	mapM_ (\p -> itemInfo o (SeekInput [p], p)) ps
@@ -140,6 +148,19 @@ globalInfo o = do
 		evalStateT (mapM_ showStat stats) (emptyStatInfo o)
 		return True
 
+autoenableInfo :: Annex ()
+autoenableInfo = showCustom "info" (SeekInput []) $ do
+	m <- SpecialRemote.specialRemoteNameMap
+		<$> SpecialRemote.autoEnableable
+	descm <- M.unionWith Remote.addName
+		<$> uuidDescMap
+		<*> pure (M.map toUUIDDesc m)
+	s <- Remote.prettyPrintUUIDsDescs
+		"autoenable special remotes"
+		descm (M.keys m)
+	showRaw (encodeBS s)
+	return True
+
 itemInfo :: InfoOptions -> (SeekInput, String) -> Annex ()
 itemInfo o (si, p) = ifM (isdir p)
 	( dirInfo o p si