When parsing git configs, support all the documented ways to write true and false, including "yes", "on", "1", etc.

This change does impact git-annex config
eg "git annex config --set annex.addunlocked on"
will store "on" and new git-annex will understand that value, while
old git-annex will error:
git-annex: bad annex.addunlocked configuration in git annex config:
Parse failure: near "on"
That seems acceptable.

Not special remote configs that are only documented as =true or =false
however. Having git-annex support other values for those would break
backwards compatability when used with old versions of git-annex. And
older versions ignore invalid special remote configs.. That would not
be a good combination.

Annex/SpecialRemote.hs

@@ -22,7 +22,6 @@ import Config
 import Remote.List
 import Logs.Remote
 import Logs.Trust
-import qualified Git.Config
 import qualified Types.Remote as Remote
 import Git.Types (RemoteName)
 
@@ -99,7 +98,7 @@ autoEnable = do
 			_ -> return ()
   where
 	configured rc = fromMaybe False $
-		Git.Config.isTrueFalse . fromProposedAccepted
+		trueFalseParser' . fromProposedAccepted
 			=<< M.lookup autoEnableField rc
 	canenable u = (/= DeadTrusted) <$> lookupTrust u
 	getenabledremotes = M.fromList

Annex/SpecialRemote/Config.hs

@@ -17,7 +17,6 @@ import Types.UUID
 import Types.ProposedAccepted
 import Types.RemoteConfig
 import Types.GitConfig
-import qualified Git.Config
 
 import qualified Data.Map as M
 import qualified Data.Set as S
@@ -242,9 +241,17 @@ yesNoParser f v fd = genParser yesno f v fd
 	yesno _ = Nothing
 
 trueFalseParser :: RemoteConfigField -> Bool -> FieldDesc -> RemoteConfigFieldParser
-trueFalseParser f v fd = genParser Git.Config.isTrueFalse f v fd
+trueFalseParser f v fd = genParser trueFalseParser' f v fd
 	(Just (ValueDesc "true or false"))
 
+-- Not using Git.Config.isTrueFalse because git supports
+-- a lot of other values for true and false in its configs,
+-- and this is not a git config and we want to avoid that mess.
+trueFalseParser' :: String -> Maybe Bool
+trueFalseParser' "true" = Just True
+trueFalseParser' "false" = Just False
+trueFalseParser' _ = Nothing
+
 genParser
 	:: Typeable t
 	=> (String -> Maybe t)

CHANGELOG

@@ -9,6 +9,8 @@ git-annex (8.20200331) UNRELEASED; urgency=medium
   * Fix a potential failure to parse git config.
   * Support boolean git configs that are represented by the name of the
     setting with no value, eg "core.bare" is the same as "core.bare = true".
+  * When parsing git configs, support all the documented ways to write
+    true and false, including "yes", "on", "1", etc.
 
  -- Joey Hess <id@joeyh.name>  Mon, 30 Mar 2020 15:58:34 -0400
 

Git/Config.hs

@@ -166,8 +166,17 @@ isTrueFalse = isTrueFalse' . ConfigValue . encodeBS'
 
 isTrueFalse' :: ConfigValue -> Maybe Bool
 isTrueFalse' (ConfigValue s)
+	| s' == "yes" = Just True
+	| s' == "on" = Just True
 	| s' == "true" = Just True
+	| s' == "1" = Just True
+
+	| s' == "no" = Just False
+	| s' == "off" = Just False
 	| s' == "false" = Just False
+	| s' == "0" = Just False
+	| s' == "" = Just False
+
 	| otherwise = Nothing
   where
 	s' = S8.map toLower s