-readParseDatabase :: PackageDBName -> IO (PackageDBName,PackageDB)
-readParseDatabase filename = do
- str <- readFile filename `catchIO` \_ -> return emptyPackageConfig
- let packages = map convertPackageInfoIn $ read str
- Exception.evaluate packages
- `catchError` \e->
- die ("error while parsing " ++ filename ++ ": " ++ show e)
- return (filename,packages)
-
-emptyPackageConfig :: String
-emptyPackageConfig = "[]"
+readParseDatabase :: Maybe (PackageDBName,Bool)
+ -> PackageDBName
+ -> IO (PackageDBName,PackageDB)
+readParseDatabase mb_user_conf filename
+ -- the user database (only) is allowed to be non-existent
+ | Just (user_conf,False) <- mb_user_conf, filename == user_conf
+ = return (filename, [])
+ | otherwise
+ = do str <- readFile filename
+ let packages = map convertPackageInfoIn $ read str
+ Exception.evaluate packages
+ `catchError` \e->
+ die ("error while parsing " ++ filename ++ ": " ++ show e)
+ return (filename,packages)