Merge #11307: wallet: Display non-HD error on first run

fadf31e wallet: Display non-HD error on first run (MarcoFalke)

Pull request description:

  On current master a fresh wallet created with `-usehd=0` is silently created as HD wallet.
  An error should be displayed on the first run.

  Also, this restores a test that was removed in c22a53c

  Fixes: #11313

Tree-SHA512: 226a4129984324f88a431c7e2726383f6841711f0227d8e9f5b4f89d4bb9f2b8e922e6cf0a6f91d6efa747d139543a236b9f29326fc5d1e5d6f1dea2465d9b85

test/functional/wallet-hd.py

@@ -20,6 +20,12 @@ class WalletHDTest(BitcoinTestFramework):
     def run_test (self):
         tmpdir = self.options.tmpdir
 
+        # Make sure can't switch off usehd after wallet creation
+        self.stop_node(1)
+        self.assert_start_raises_init_error(1, ['-usehd=0'], 'already existing HD wallet')
+        self.start_node(1)
+        connect_nodes_bi(self.nodes, 0, 1)
+
         # Make sure we use hd, keep masterkeyid
         masterkeyid = self.nodes[1].getwalletinfo()['hdmasterkeyid']
         assert_equal(len(masterkeyid), 40)