test: Run invalid_txs.InputMissing test in feature_block

Author: MarcoFalke

src/wallet/test/wallet_tests.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2012-2018 The Bitcoin Core developers
+// Copyright (c) 2012-2019 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
@@ -47,7 +47,7 @@ BOOST_FIXTURE_TEST_CASE(scan_for_wallet_transactions, TestChain100Setup)
 
     auto locked_chain = chain->lock();
 
-    // Verify ScanForWalletTransactions accomodates a null start block.
+    // Verify ScanForWalletTransactions accommodates a null start block.
     {
         CWallet wallet(*chain, WalletLocation(), WalletDatabase::CreateDummy());
         AddKey(wallet, coinbaseKey);

test/functional/feature_block.py

@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-# Copyright (c) 2015-2018 The Bitcoin Core developers
+# Copyright (c) 2015-2019 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 """Test block processing."""
@@ -137,20 +137,29 @@ def run_test(self):
         for TxTemplate in invalid_txs.iter_all_templates():
             template = TxTemplate(spend_tx=attempt_spend_tx)
 
-            # Something about the serialization code for missing inputs creates
-            # a different hash in the test client than on bitcoind, resulting
-            # in a mismatching merkle root during block validation.
-            # Skip until we figure out what's going on.
-            if TxTemplate == invalid_txs.InputMissing:
-                continue
             if template.valid_in_block:
                 continue
 
             self.log.info("Reject block with invalid tx: %s", TxTemplate.__name__)
             blockname = "for_invalid.%s" % TxTemplate.__name__
             badblock = self.next_block(blockname)
             badtx = template.get_tx()
-            self.sign_tx(badtx, attempt_spend_tx)
+            if TxTemplate != invalid_txs.InputMissing:
+                self.sign_tx(badtx, attempt_spend_tx)
+            else:
+                # Segwit is active in regtest at this point, so to deserialize a
+                # transaction without any inputs correctly, we set the outputs
+                # to an empty list. This is a hack, as the serialization of an
+                # empty list of outputs is deserialized as flags==0 and thus
+                # deserialization of the outputs is skipped.
+                # A policy check requires "loose" txs to be of a minimum size,
+                # so vtx is not set to be empty in the TxTemplate class and we
+                # only apply the workaround where txs are not "loose", i.e. in
+                # blocks.
+                #
+                # The workaround has the purpose that both sides calculate
+                # the same tx hash in the merkle tree
+                badtx.vout = []
             badtx.rehash()
             badblock = self.update_block(blockname, [badtx])
             self.sync_blocks(