improve thirdpartypopulated support

May actually work now.

Note that, importKey now has to add the size to the key if it's supposed
to have size. Remote.Directory relied on the importer adding the size,
which is no longer done, so it was changed; it was the only one.
This way, importKey does not need to behave differently between regular
and thirdpartypopulated imports.

Command/Sync.hs

@@ -77,7 +77,6 @@ import Utility.Process.Transcript
 import Utility.Tuple
 
 import Control.Concurrent.MVar
-import Control.Concurrent.STM
 import qualified Data.Map as M
 import qualified Data.ByteString as S
 import Data.Char
@@ -492,24 +491,18 @@ importRemote importcontent o mergeconfig remote currbranch
  - updated, because the filenames are the names of annex object files,
  - not suitable for a tracking branch. Does not transfer any content. -}
 importThirdPartyPopulated :: Remote -> CommandSeek
-importThirdPartyPopulated remote = do
-	importabletvar <- liftIO $ newTVarIO Nothing
-	void $ includeCommandAction (Command.Import.listContents remote ImportTree (CheckGitIgnore False) importabletvar)
-	liftIO (atomically (readTVar importabletvar)) >>= \case
-		Nothing -> return ()
-		Just importable -> 
-			importKeys remote ImportTree False False importable >>= \case
-				Just importablekeys -> go importablekeys
-				Nothing -> warning $ concat
-					[ "Failed to import from"
-					, Remote.name remote
-					]
+importThirdPartyPopulated remote = 
+	void $ includeCommandAction $ starting "list" ai si $
+		Command.Import.listContents' remote ImportTree (CheckGitIgnore False) go
   where
-	go importablekeys = void $ includeCommandAction $ starting "pull" ai si $ do
-		(_imported, updatestate) <- recordImportTree remote ImportTree importablekeys
-		next $ do
-			updatestate
-			return True
+	go importable = importKeys remote ImportTree False True importable >>= \case
+		Just importablekeys -> do
+			(_imported, updatestate) <- recordImportTree remote ImportTree importablekeys
+			next $ do
+				updatestate
+				return True
+		Nothing -> next $ return False
+
 	ai = ActionItemOther (Just (Remote.name remote))
 	si = SeekInput []