wait for git lstree to exit

Git/LsTree.hs

@@ -1,6 +1,6 @@
 {- git ls-tree interface
  -
- - Copyright 2011 Joey Hess <id@joeyh.name>
+ - Copyright 2011-2016 Joey Hess <id@joeyh.name>
  -
  - Licensed under the GNU GPL version 3 or higher.
  -}
@@ -32,9 +32,10 @@ data TreeItem = TreeItem
 
 {- Lists the complete contents of a tree, recursing into sub-trees,
  - with lazy output. -}
-lsTree :: Ref -> Repo -> IO [TreeItem]
-lsTree t repo = map parseLsTree
-	<$> pipeNullSplitZombie (lsTreeParams t []) repo
+lsTree :: Ref -> Repo -> IO ([TreeItem], IO Bool)
+lsTree t repo = do
+	(l, cleanup) <- pipeNullSplit (lsTreeParams t []) repo
+	return (map parseLsTree l, cleanup)
 
 lsTreeParams :: Ref -> [CommandParam] -> [CommandParam]
 lsTreeParams r ps =