Few more tiny trivial fixes

test/functional/dip3-deterministicmns.py

@@ -34,8 +34,8 @@ class DIP3Test(BitcoinTestFramework):
 
     def start_controller_node(self, extra_args=None):
         self.log.info("starting controller node")
-        if self.nodes is None:
-            self.nodes = [None]
+        if len(self.nodes) == 0:
+            self.nodes.append(None)
         args = self.extra_args
         if extra_args is not None:
             args += extra_args

test/functional/keypool-hd.py

@@ -28,7 +28,7 @@ class KeyPoolTest(BitcoinTestFramework):
 
         # Encrypt wallet and wait to terminate
         nodes[0].encryptwallet('test')
-        bitcoind_processes[0].wait()
+        self.bitcoind_processes[0].wait()
         # Restart node 0
         nodes[0] = self.start_node(0, self.options.tmpdir, ['-usehd=1'], stderr=sys.stdout)
         # Keep creating keys

test/functional/test_framework/test_framework.py

@@ -421,7 +421,7 @@ class BitcoinTestFramework(object):
                     args.extend(extra_args)
                 self.bitcoind_processes[i] = subprocess.Popen(args, stderr=stderr)
                 self.log.debug("initialize_chain: dashd started, waiting for RPC to come up")
-                self.wait_for_bitcoind_start(bitcoind_processes[i], datadir, i)
+                self._wait_for_bitcoind_start(self.bitcoind_processes[i], datadir, i)
                 self.log.debug("initialize_chain: RPC successfully started")
 
             self.nodes = []