Merge bitcoin/bitcoin#25590: wallet: Precompute Txdata after setting PSBT inputs' UTXOs

d2ed976 wallet: Precompute Txdata after setting PSBT inputs' UTXOs (Andrew Chow)

Pull request description:

  If we are given a PSBT that is missing one or more input UTXOs, our
  PrecomputedTransactionData will be incorrect and missing information
  that it should otherwise have, and therefore we may not produce a
  signature when we should. To avoid this problem, we can do the
  precomputation after we have set the UTXOs the wallet is able to set for
  the PSBT.

  Also adds a test for this behavior.

ACKs for top commit:
  instagibbs:
    reACK bitcoin/bitcoin@d2ed976
  Sjors:
    ACK d2ed976
  aureleoules:
    ACK d2ed976.

Tree-SHA512: 71beb6c7946096e82cfca83f36277302aa9e69d27b4f6d73d7d8f2f9f0ea1c0d653e846fa6aebee5e4763f56f950b4481240e953f6a2412caa84908d519171e1

Author: MacroFake

src/wallet/wallet.cpp

@@ -1984,7 +1984,6 @@ TransactionError CWallet::FillPSBT(PartiallySignedTransaction& psbtx, bool& comp
     if (n_signed) {
         *n_signed = 0;
     }
-    const PrecomputedTransactionData txdata = PrecomputePSBTData(psbtx);
     LOCK(cs_wallet);
     // Get all of the previous transactions
     for (unsigned int i = 0; i < psbtx.tx->vin.size(); ++i) {
@@ -2008,6 +2007,8 @@ TransactionError CWallet::FillPSBT(PartiallySignedTransaction& psbtx, bool& comp
         }
     }
 
+    const PrecomputedTransactionData txdata = PrecomputePSBTData(psbtx);
+
     // Fill in information from ScriptPubKeyMans
     for (ScriptPubKeyMan* spk_man : GetAllScriptPubKeyMans()) {
         int n_signed_this_spkm = 0;

test/functional/rpc_psbt.py

@@ -22,6 +22,7 @@
     assert_greater_than,
     assert_raises_rpc_error,
     find_output,
+    find_vout_for_address,
 )
 from test_framework.wallet_util import bytes_to_wif
 
@@ -764,5 +765,15 @@ def test_psbt_input_keys(psbt_input, keys):
             psbt = self.nodes[0].walletprocesspsbt(psbt)["psbt"]
             self.nodes[0].sendrawtransaction(self.nodes[0].finalizepsbt(psbt)["hex"])
 
+            self.log.info("Test that walletprocesspsbt both updates and signs a non-updated psbt containing Taproot inputs")
+            addr = self.nodes[0].getnewaddress("", "bech32m")
+            txid = self.nodes[0].sendtoaddress(addr, 1)
+            vout = find_vout_for_address(self.nodes[0], txid, addr)
+            psbt = self.nodes[0].createpsbt([{"txid": txid, "vout": vout}], [{self.nodes[0].getnewaddress(): 0.9999}])
+            signed = self.nodes[0].walletprocesspsbt(psbt)
+            rawtx = self.nodes[0].finalizepsbt(signed["psbt"])["hex"]
+            self.nodes[0].sendrawtransaction(rawtx)
+            self.generate(self.nodes[0], 1)
+
 if __name__ == '__main__':
     PSBTTest().main()