Merge ffaac6e into merged_master (Bitcoin PR #16378)

Adds a new "send" RPC which I didn't really look at too closely to match
our other RPC modifications. In particular our backport of #17211 adds a
"solving_data" field to other transaction-creation RPCs, but not this
one. (But I checked the current status of #17211 and Andy hasn't updated
upstream either, just passes NullUniValue to FundTransaction from `send`.
So that's what I did here.)

doc/release-notes-16378.md

@@ -0,0 +1,5 @@
+RPC
+---
+- A new `send` RPC with similar syntax to `walletcreatefundedpsbt`, including
+  support for coin selection and a custom fee rate. Using the new `send` method
+  is encouraged: `sendmany` and `sendtoaddress` may be deprecated in a future release.

src/rpc/client.cpp

@@ -128,6 +128,9 @@ static const CRPCConvertParam vRPCConvertParams[] =
     { "gettxoutproof", 0, "txids" },
     { "lockunspent", 0, "unlock" },
     { "lockunspent", 1, "transactions" },
+    { "send", 0, "outputs" },
+    { "send", 1, "conf_target" },
+    { "send", 3, "options" },
     { "importprivkey", 2, "rescan" },
     { "importaddress", 2, "rescan" },
     { "importaddress", 3, "p2sh" },

src/rpc/rawtransaction_util.cpp

@@ -145,10 +145,15 @@ void CreatePegInInput(CMutableTransaction& mtx, uint32_t input_idx, Sidechain::B
 
 CMutableTransaction ConstructTransaction(const UniValue& inputs_in, const UniValue& outputs_in, const UniValue& locktime, bool rbf, const UniValue& assets_in, std::vector<CPubKey>* output_pubkeys_out, bool allow_peg_in)
 {
-    if (inputs_in.isNull() || outputs_in.isNull())
-        throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, arguments 1 and 2 must be non-null");
+    if (outputs_in.isNull())
+        throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, output argument must be non-null");
+
+    UniValue inputs;
+    if (inputs_in.isNull())
+        inputs = UniValue::VARR;
+    else
+        inputs = inputs_in.get_array();
 
-    UniValue inputs = inputs_in.get_array();
     const bool outputs_is_obj = outputs_in.isObject();
     UniValue outputs = outputs_is_obj ? outputs_in.get_obj() : outputs_in.get_array();
 

test/functional/rpc_fundrawtransaction.py

@@ -231,7 +231,7 @@ def test_invalid_change_address(self):
         dec_tx  = self.nodes[2].decoderawtransaction(rawtx)
         assert_equal(utx['txid'], dec_tx['vin'][0]['txid'])
 
-        assert_raises_rpc_error(-5, "changeAddress must be a valid address", self.nodes[2].fundrawtransaction, rawtx, {'changeAddress':'foobar'})
+        assert_raises_rpc_error(-5, "Change address must be a valid address", self.nodes[2].fundrawtransaction, rawtx, {'changeAddress':'foobar'})
 
     def test_valid_change_address(self):
         self.log.info("Test fundrawtxn with a provided change address")

test/functional/rpc_psbt.py

@@ -126,6 +126,9 @@ def run_basic_tests(self, confidential):
         #  just make sure that we added at least one input
         assert len(self.nodes[0].decodepsbt(psbtx1)['tx']['vin']) > 1
 
+        # Inputs argument can be null
+        self.nodes[0].walletcreatefundedpsbt(None, {self.nodes[2].getnewaddress():10})
+
         # Node 1 should not be able to add anything to it but still return the psbtx same as before
         psbtx = self.nodes[1].walletfillpsbtdata(psbtx1)['psbt']
         assert_equal(psbtx1, psbtx)

test/functional/test_runner.py

@@ -250,6 +250,7 @@
     'rpc_estimatefee.py',
     'rpc_getblockstats.py',
     'wallet_create_tx.py',
+    'wallet_send.py',
     'p2p_fingerprint.py',
     'feature_uacomment.py',
     'wallet_coinbase_category.py',