fix _put_recursive tree grow case

src/atmst/mst/node_wrangler.py

@@ -73,7 +73,11 @@ def _put_here(self, node: MSTNode, key: str, val: CID) -> MSTNode:
 	def _put_recursive(self, node: MSTNode, key: str, val: CID, key_height: int, tree_height: int) -> MSTNode:
 		if key_height > tree_height: # we need to grow the tree
 			return self.ns.stored_node(self._put_recursive(
-				MSTNode.empty_root(),
+				self.ns.stored_node(MSTNode(
+					keys=(),
+					vals=(),
+					subtrees=(node.cid,)
+				)),
 				key, val, key_height, tree_height + 1
 			))
 

tests/test_mst_diff.py

@@ -5,6 +5,13 @@
 from atmst.mst.node import MSTNode
 from cbrrr import CID
 
+def dump_mst(ns: NodeStore, cid: CID, lvl=0):
+	node = ns.get_node(cid)
+	print("  "*lvl + "-", node)
+	for subtree in node.subtrees:
+		if subtree:
+			dump_mst(ns, subtree, lvl+1)
+
 class MSTDiffTestCase(unittest.TestCase):
 	def setUp(self):
 		keys = []
@@ -60,6 +67,12 @@ def test_insertion_order_independent(self):
 		for k in keys:
 			mst_c = wrangler.put_record(mst_c, k, CID.cidv1_dag_cbor_sha256_32_from(k.encode()))
 
+		#print()
+		#dump_mst(self.ns, mst_a)
+
+		#print()
+		#dump_mst(self.ns, mst_b)
+
 		self.assertEqual(mst_a, mst_b)
 		self.assertEqual(mst_a, mst_c)