message: Improve blocksdir functional test.
  A new node should not create an unused `blocks` directory in the root of
  the data directory when `-testnet` or `-regtest` is specified.
diff: @@ -18,6 +18,8 @@ class BlocksdirTest(BitcoinTestFramework):
  def run_test(self):
  self.stop_node(0)
  + assert os.path.isdir(os.path.join(self.nodes[0].datadir, "regtest", "blocks"))
  + assert not os.path.isdir(os.path.join(self.nodes[0].datadir, "blocks"))
  shutil.rmtree(self.nodes[0].datadir)
  initialize_datadir(self.options.tmpdir, 0)
  self.log.info("Starting with nonexistent blocksdir ...")
  