Update name_ant_workflow.py.

Upstream bitcoin/bitcoin#17211 solved a
long-standing issue for doing atomic trades with names (namely that
the buyer's wallet was not able to directly fund a transaction with the
non-wallet name input in it).

Based on this, we can now streamline name_ant_workflow.py to make use
of this new feature.  This allows us to properly use fundrawtransaction
to fund the final transaction including already the name input and output,
and thus with correct fee estimation done.  (Previously we just funded a
dummy transaction with a guessed higher fee, and then added in the name
input and output manually, hoping the fee would still be fine.)

test/functional/name_ant_workflow.py

@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-# Copyright (c) 2020 Daniel Kraft
+# Copyright (c) 2020-2021 Daniel Kraft
 # Distributed under the MIT/X11 software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
@@ -28,31 +28,43 @@ def run_test (self):
     self.sync_blocks ()
     self.checkName (0, "x/name", "value", None, False)
 
-    # fundrawtransaction and friends does not support non-wallet provided
-    # inputs.  Thus we have to first build up the funded transaction without
-    # the name coins and a slightly higher fee, and then combine it with the
-    # name input/output to obtain the final raw transaction.
-    addrPayment = self.nodes[0].getnewaddress ()
-    outs = [{addrPayment: 10}]
-    options = {
-      "fee_rate": 100,
-    }
-    part1 = self.nodes[1].walletcreatefundedpsbt ([], outs, 0, options)["psbt"]
+    # We construct the base transaction first, with just the name input,
+    # name output (including the operation) and the payment output.
+    # We then apply fundrawtransaction to add the necessary input and change
+    # for the payment; this needs solving data for the non-wallet input
+    # (the name) to be passed in, which in this case is the pubkey for the
+    # name input address.
 
+    addrPayment = self.nodes[0].getnewaddress ()
     addrNm = self.nodes[1].getnewaddress ()
+
     nmData = self.nodes[0].name_show ("x/name")
-    part2 = self.nodes[0].createpsbt ([nmData], [{addrNm: 0.01}])
+    addrNmOld = nmData["address"]
+    pubKey = self.nodes[0].getaddressinfo (addrNmOld)["pubkey"]
+
+    tx = self.nodes[1].createrawtransaction ([nmData], {
+      addrPayment: 10,
+      addrNm: 0.01,
+    })
+    vout = self.rawtxOutputIndex (1, tx, addrNm)
     nameOp = {
       "op": "name_update",
       "name": "x/name",
       "value": "updated",
     }
-    part2 = self.nodes[1].namepsbt (part2, 0, nameOp)["psbt"]
-    combined = self.nodes[1].joinpsbts ([part1, part2])
+    tx = self.nodes[1].namerawtransaction (tx, vout, nameOp)["hex"]
+
+    options = {
+      "solving_data": {
+        "pubkeys": [pubKey],
+      },
+    }
+    tx = self.nodes[1].fundrawtransaction (tx, options)["hex"]
+    psbt = self.nodes[1].converttopsbt (tx)
 
     # Sign and broadcast the partial tx.
-    sign1 = self.nodes[0].walletprocesspsbt (combined)
-    sign2 = self.nodes[1].walletprocesspsbt (combined)
+    sign1 = self.nodes[0].walletprocesspsbt (psbt)
+    sign2 = self.nodes[1].walletprocesspsbt (psbt)
     combined = self.nodes[1].combinepsbt ([sign1["psbt"], sign2["psbt"]])
     tx = self.nodes[1].finalizepsbt (combined)
     assert_equal (tx["complete"], True)