rpc: include_unsafe option for fundrawtransaction

Allow RPC users to opt-in to unsafe inputs when funding a raw transaction.

Applications that need to manage a complex RBF flow (such as lightning
nodes using anchor outputs) are very limited if they can only use safe inputs.

Fixes #21299

test/functional/rpc_fundrawtransaction.py

@@ -96,6 +96,7 @@ class RawTransactionsTest(BitcoinTestFramework):
         self.test_option_subtract_fee_from_outputs()
         self.test_subtract_fee_with_presets()
         self.test_transaction_too_large()
+        self.test_include_unsafe()
 
     def test_change_position(self):
         """Ensure setting changePosition in fundraw with an exact match is handled properly."""
@@ -928,6 +929,40 @@ class RawTransactionsTest(BitcoinTestFramework):
         self.nodes[0].generate(10)
         assert_raises_rpc_error(-4, "Transaction too large", recipient.fundrawtransaction, rawtx)
 
+    def test_include_unsafe(self):
+        self.log.info("Test fundrawtxn with unsafe inputs")
+
+        self.nodes[0].createwallet("unsafe")
+        wallet = self.nodes[0].get_wallet_rpc("unsafe")
+
+        # We receive unconfirmed funds from external keys (unsafe outputs).
+        addr = wallet.getnewaddress()
+        txid1 = self.nodes[2].sendtoaddress(addr, 6)
+        txid2 = self.nodes[2].sendtoaddress(addr, 4)
+        self.sync_all()
+        vout1 = find_vout_for_address(wallet, txid1, addr)
+        vout2 = find_vout_for_address(wallet, txid2, addr)
+
+        # Unsafe inputs are ignored by default.
+        rawtx = wallet.createrawtransaction([], [{self.nodes[2].getnewaddress(): 5}])
+        assert_raises_rpc_error(-4, "Insufficient funds", wallet.fundrawtransaction, rawtx)
+
+        # But we can opt-in to use them for funding.
+        fundedtx = wallet.fundrawtransaction(rawtx, {"include_unsafe": True})
+        tx_dec = wallet.decoderawtransaction(fundedtx['hex'])
+        assert any([txin['txid'] == txid1 and txin['vout'] == vout1 for txin in tx_dec['vin']])
+        signedtx = wallet.signrawtransactionwithwallet(fundedtx['hex'])
+        wallet.sendrawtransaction(signedtx['hex'])
+
+        # And we can also use them once they're confirmed.
+        self.nodes[0].generate(1)
+        rawtx = wallet.createrawtransaction([], [{self.nodes[2].getnewaddress(): 3}])
+        fundedtx = wallet.fundrawtransaction(rawtx, {"include_unsafe": True})
+        tx_dec = wallet.decoderawtransaction(fundedtx['hex'])
+        assert any([txin['txid'] == txid2 and txin['vout'] == vout2 for txin in tx_dec['vin']])
+        signedtx = wallet.signrawtransactionwithwallet(fundedtx['hex'])
+        wallet.sendrawtransaction(signedtx['hex'])
+
 
 if __name__ == '__main__':
     RawTransactionsTest().main()

test/functional/rpc_psbt.py

@@ -394,6 +394,14 @@ class PSBTTest(BitcoinTestFramework):
         # We don't care about the decode result, but decoding must succeed.
         self.nodes[0].decodepsbt(double_processed_psbt["psbt"])
 
+        # Make sure unsafe inputs are included if specified
+        self.nodes[2].createwallet(wallet_name="unsafe")
+        wunsafe = self.nodes[2].get_wallet_rpc("unsafe")
+        self.nodes[0].sendtoaddress(wunsafe.getnewaddress(), 2)
+        self.sync_mempools()
+        assert_raises_rpc_error(-4, "Insufficient funds", wunsafe.walletcreatefundedpsbt, [], [{self.nodes[0].getnewaddress(): 1}])
+        wunsafe.walletcreatefundedpsbt([], [{self.nodes[0].getnewaddress(): 1}], 0, {"include_unsafe": True})
+
         # BIP 174 Test Vectors
 
         # Check that unknown values are just passed through

test/functional/wallet_send.py

@@ -33,12 +33,15 @@ class WalletSendTest(BitcoinTestFramework):
     def test_send(self, from_wallet, to_wallet=None, amount=None, data=None,
                   arg_conf_target=None, arg_estimate_mode=None, arg_fee_rate=None,
                   conf_target=None, estimate_mode=None, fee_rate=None, add_to_wallet=None, psbt=None,
-                  inputs=None, add_inputs=None, change_address=None, change_position=None, change_type=None,
+                  inputs=None, add_inputs=None, include_unsafe=None, change_address=None, change_position=None, change_type=None,
                   include_watching=None, locktime=None, lock_unspents=None, replaceable=None, subtract_fee_from_outputs=None,
                   expect_error=None):
         assert (amount is None) != (data is None)
 
-        from_balance_before = from_wallet.getbalance()
+        from_balance_before = from_wallet.getbalances()["mine"]["trusted"]
+        if include_unsafe:
+            from_balance_before += from_wallet.getbalances()["mine"]["untrusted_pending"]
+
         if to_wallet is None:
             assert amount is None
         else:
@@ -71,6 +74,8 @@ class WalletSendTest(BitcoinTestFramework):
             options["inputs"] = inputs
         if add_inputs is not None:
             options["add_inputs"] = add_inputs
+        if include_unsafe is not None:
+            options["include_unsafe"] = include_unsafe
         if change_address is not None:
             options["change_address"] = change_address
         if change_position is not None:
@@ -133,6 +138,10 @@ class WalletSendTest(BitcoinTestFramework):
             assert not "txid" in res
             assert "psbt" in res
 
+        from_balance = from_wallet.getbalances()["mine"]["trusted"]
+        if include_unsafe:
+            from_balance += from_wallet.getbalances()["mine"]["untrusted_pending"]
+
         if add_to_wallet and not include_watching:
             # Ensure transaction exists in the wallet:
             tx = from_wallet.gettransaction(res["txid"])
@@ -143,13 +152,13 @@ class WalletSendTest(BitcoinTestFramework):
             assert tx
             if amount:
                 if subtract_fee_from_outputs:
-                    assert_equal(from_balance_before - from_wallet.getbalance(), amount)
+                    assert_equal(from_balance_before - from_balance, amount)
                 else:
-                    assert_greater_than(from_balance_before - from_wallet.getbalance(), amount)
+                    assert_greater_than(from_balance_before - from_balance, amount)
             else:
                 assert next((out for out in tx["vout"] if out["scriptPubKey"]["asm"] == "OP_RETURN 35"), None)
         else:
-            assert_equal(from_balance_before, from_wallet.getbalance())
+            assert_equal(from_balance_before, from_balance)
 
         if to_wallet:
             self.sync_mempools()
@@ -440,6 +449,14 @@ class WalletSendTest(BitcoinTestFramework):
         self.log.info("Subtract fee from output")
         self.test_send(from_wallet=w0, to_wallet=w1, amount=1, subtract_fee_from_outputs=[0])
 
+        self.log.info("Include unsafe inputs")
+        self.nodes[1].createwallet(wallet_name="w5")
+        w5 = self.nodes[1].get_wallet_rpc("w5")
+        self.test_send(from_wallet=w0, to_wallet=w5, amount=2)
+        self.test_send(from_wallet=w5, to_wallet=w0, amount=1, expect_error=(-4, "Insufficient funds"))
+        res = self.test_send(from_wallet=w5, to_wallet=w0, amount=1, include_unsafe=True)
+        assert res["complete"]
+
 
 if __name__ == '__main__':
     WalletSendTest().main()