[wallet] [tests] Test disallowed multiwallet params

Add a test to check that bitcoind fails to start when specifying
-zapwallettxes, -salvagewallet and -upgradewallet when running in
multiwallet mode.

Author: jnewbery

test/functional/wallet_multiwallet.py

@@ -91,6 +91,19 @@ def run_test(self):
         open(not_a_dir, 'a').close()
         self.nodes[0].assert_start_raises_init_error(['-walletdir=' + not_a_dir], 'Error: Specified -walletdir "' + not_a_dir + '" is not a directory')
 
+        self.log.info("Do not allow -zapwallettxes with multiwallet")
+        self.nodes[0].assert_start_raises_init_error(['-zapwallettxes', '-wallet=w1', '-wallet=w2'], "Error: -zapwallettxes is only allowed with a single wallet file")
+        self.nodes[0].assert_start_raises_init_error(['-zapwallettxes=1', '-wallet=w1', '-wallet=w2'], "Error: -zapwallettxes is only allowed with a single wallet file")
+        self.nodes[0].assert_start_raises_init_error(['-zapwallettxes=2', '-wallet=w1', '-wallet=w2'], "Error: -zapwallettxes is only allowed with a single wallet file")
+
+        self.log.info("Do not allow -salvagewallet with multiwallet")
+        self.nodes[0].assert_start_raises_init_error(['-salvagewallet', '-wallet=w1', '-wallet=w2'], "Error: -salvagewallet is only allowed with a single wallet file")
+        self.nodes[0].assert_start_raises_init_error(['-salvagewallet=1', '-wallet=w1', '-wallet=w2'], "Error: -salvagewallet is only allowed with a single wallet file")
+
+        self.log.info("Do not allow -upgradewallet with multiwallet")
+        self.nodes[0].assert_start_raises_init_error(['-upgradewallet', '-wallet=w1', '-wallet=w2'], "Error: -upgradewallet is only allowed with a single wallet file")
+        self.nodes[0].assert_start_raises_init_error(['-upgradewallet=1', '-wallet=w1', '-wallet=w2'], "Error: -upgradewallet is only allowed with a single wallet file")
+
         # if wallets/ doesn't exist, datadir should be the default wallet dir
         wallet_dir2 = data_dir('walletdir')
         os.rename(wallet_dir(), wallet_dir2)