avoid cycles

diff --git a/Remote/Mask.hs b/Remote/Mask.hs
index f21a8513d5c20e1afa6ee235bef3f53de6881617..b4b981fbe9bdb601633a79f5b2ba3f80de18a462 100644 (file)
--- a/Remote/Mask.hs
+++ b/Remote/Mask.hs
@@ -46,7 +46,7 @@ remote = specialRemoteType $ RemoteType
 
 gen :: Git.Repo -> UUID -> RemoteConfig -> RemoteGitConfig -> RemoteStateHandle -> Annex (Maybe Remote)
 gen r u rc gc rs = do
-       maskedremote <- mkMaskedRemote rc gc
+       maskedremote <- mkMaskedRemote rc gc u
        c <- parsedRemoteConfig remote rc
        cst <- remoteCost gc c $ encryptedRemoteCostAdj + semiExpensiveRemoteCost
        let this = Remote
@@ -152,21 +152,19 @@ newtype MaskedRemote = MaskedRemote { getMaskedRemote :: Annex Remote }
 -- findMaskedRemote won't work until the remote list has been populated,
 -- so has to be done on the fly rather than at generation time.
 -- This caches it for speed.
-mkMaskedRemote :: RemoteConfig -> RemoteGitConfig -> Annex MaskedRemote
-mkMaskedRemote c gc = do
+mkMaskedRemote :: RemoteConfig -> RemoteGitConfig -> UUID -> Annex MaskedRemote
+mkMaskedRemote c gc u = do
        v <- liftIO $ newTMVarIO Nothing
        return $ MaskedRemote $ 
                liftIO (atomically (takeTMVar v)) >>= \case
                        Just maskedremote -> return maskedremote
                        Nothing -> do
-                               maskedremote <- findMaskedRemote c gc
+                               maskedremote <- findMaskedRemote c gc u
                                liftIO $ atomically $ putTMVar v (Just maskedremote)
                                return maskedremote
 
--- XXX prevent using self as masked remote, and prevent using mask special
--- remote, to avoid cycles
-findMaskedRemote :: RemoteConfig -> RemoteGitConfig -> Annex Remote
-findMaskedRemote c gc = case remoteAnnexMask gc of
+findMaskedRemote :: RemoteConfig -> RemoteGitConfig -> UUID -> Annex Remote
+findMaskedRemote c gc myuuid = case remoteAnnexMask gc of
        -- This remote was autoenabled, so use any remote with the
        -- uuid of the masked remote, so that it can also be autoenabled.
        Just "true" -> 
@@ -183,7 +181,12 @@ findMaskedRemote c gc = case remoteAnnexMask gc of
        selectremote u f = do
                remotelist <- Annex.getState Annex.remotes
                case filter f remotelist of
-                       (r:_) -> return r
+                       (r:_)
+                               | uuid r == myuuid -> giveup "Mask special remote is configured to mask itself. This is not a valid configuration."
+                               -- Avoid cycles, and there is no benefit
+                               -- to masking a mask special remote.
+                               | remotetype r == remote -> giveup "Mask special remote is configured to mask another mask special remote. This is not supported."
+                               | otherwise -> return r
                        [] -> missingMaskedRemote u
 
 missingMaskedRemote :: UUID -> Annex a