.

wcfs/internal/xbtree.py

@@ -104,7 +104,7 @@ def StructureOf(node):
         if kind == bcheck.BTREE_ONE:
             b = node._bucket_type()
             b.__setstate__(keys)    # it is keys+values for BTREE_ONE case
-            return StructureOf(b)
+            return Tree([], StructureOf(b))
 
         if kind == bcheck.BTREE_NORMAL:
             return Tree(keys, *[StructureOf(_) for _ in children])