Exercise copyChildrenAndKeyFrom for Node{48,256} to itself

test_conflict_set.py

@@ -66,6 +66,21 @@ def test_inner_full_words():
         cs.check(read(1, b"\x21", b"\xc2"))
 
 
+def test_decrease_capacity():
+    # make a Node48, then a Node256
+    for count in (17, 49):
+        with DebugConflictSet() as cs:
+            for i in range(count):
+                cs.addWrites(1, write(bytes(([0] * 99) + [i])))
+            # lower its partial key length
+            cs.addWrites(2, write(bytes([0] * 98)))
+            # create work for setOldestVersion
+            for i in range(3, 1000):
+                cs.addWrites(i)
+            # setOldestVersion should decrease the capacity
+            cs.setOldestVersion(1)
+
+
 if __name__ == "__main__":
     # budget "pytest" for ctest integration without pulling in a dependency. You can of course still use pytest in local development.
     import argparse