use a subdirectory of annex.dbdir

This allows annex.dbdir to be set globally or always set to the same
value when needed. Each repository uses a subdirectory of it.

Sponsored-by: Dartmouth College's Datalad project

Types/GitConfig.hs

@@ -53,6 +53,7 @@ import Control.Concurrent.STM
 import qualified Data.Set as S
 import qualified Data.Map as M
 import qualified Data.ByteString as B
+import qualified System.FilePath.ByteString as P
 
 -- | A configurable value, that may not be fully determined yet because
 -- the global git config has not yet been loaded.
@@ -213,7 +214,8 @@ extractGitConfig configsource r = GitConfig
 	, annexPidLock = getbool (annexConfig "pidlock") False
 	, annexPidLockTimeout = Seconds $ fromMaybe 300 $
 		getmayberead (annexConfig "pidlocktimeout")
-	, annexDbDir = toRawFilePath <$> getmaybe (annexConfig "dbdir")
+	, annexDbDir = (\d -> toRawFilePath d P.</> fromUUID hereuuid)
+		<$> getmaybe (annexConfig "dbdir")
 	, annexAddUnlocked = configurable Nothing $
 		fmap Just $ getmaybe (annexConfig "addunlocked")
 	, annexSecureHashesOnly = getbool (annexConfig "securehashesonly") False