fix remote uuid learning bug

Remotes.hs

@@ -30,17 +30,22 @@ withKey key = do
 	g <- Annex.gitRepo
 	uuids <- liftIO $ keyLocations g key
 	allremotes <- remotesByCost
-	-- this only uses cached data, so may not find new remotes
+	-- This only uses cached data, so may not include new remotes
+	-- or remotes whose uuid has changed (eg by a different drive being
+	-- mounted at their location). So unless it happens to find all
+	-- remotes, try harder, loading the remotes' configs.
 	remotes <- reposByUUID allremotes uuids
-	if (0 == length remotes)
+	remotesread <- Annex.flagIsSet RemotesRead
+	if ((length allremotes /= length remotes) && not remotesread)
 		then tryharder allremotes uuids
 		else return remotes
 	where
 		tryharder allremotes uuids = do
-			-- more expensive; check each remote's config
+			-- more expensive; read each remote's config
 			mayberemotes <- mapM tryGitConfigRead allremotes
 			let allremotes' = catMaybes mayberemotes
 			remotes' <- reposByUUID allremotes' uuids
+			Annex.flagChange RemotesRead True
 			return remotes'
 
 {- Cost Ordered list of remotes. -}

TODO

@@ -1,9 +1,6 @@
 * bug: cannot "git annex ../foo"   (GitRepo.relative is buggy and
   git-ls-files also refuses w/o --full-name, which would need other changes)
 
-* bug: doesn't learn new remote's uuids if a known (but maybe not accessible) 
-  uuids has a wanted file
-
 * --push/--pull should take a reponame and files, and push those files
   to that repo; dropping them from the current repo
 

TypeInternals.hs

@@ -10,8 +10,10 @@ import Data.String.Utils
 
 import qualified GitRepo as Git
 
--- command-line flags
-data Flag = Force deriving (Eq, Read, Show)
+data Flag = 
+	Force |		-- command-line flags
+	RemotesRead	-- indicates that remote repo configs have been read
+		deriving (Eq, Read, Show)
 
 -- git-annex's runtime state type doesn't really belong here,
 -- but it uses Backend, so has to be here to avoid a depends loop.