Merge bitcoin/bitcoin#23202: wallet: allow psbtbumpfee to work with txs with external inputs

c3b099ace031758cafeec08c38bedbf717d6b7fe wallet, tests: Test bumpfee's max input weight calculation (Andrew Chow)
116a620ce7e6724906d63de80a8a757004f22477 Make DUMMY_CHECKER availble outside of script/sign.cpp (Andrew Chow)
ff638323d1cde68b537bb20cf096cba4e88ac4eb test, bumpfee: Check that psbtbumpfee can bump txs with external inputs (Andrew Chow)
1bc8106d4cb75f7d4862d4651f30bd2df9cfeb34 bumpfee: be able to bump fee of a tx with external inputs (Andrew Chow)
31dd3dc9e5b27fa2bbb5170ad98107a36fe55958 bumpfee: Clear scriptSigs and scriptWitnesses before calculated max size (Andrew Chow)
a0c3afb898016c2e0a76dc48f68eaa5c3ae6282c bumpfee: extract weights of external inputs when bumping fee (Andrew Chow)
612f1e44fe7ead319ae87653607614dd1bc14d60 bumpfee: Calculate fee by looking up UTXOs (Andrew Chow)

Pull request description:

  This PR allows `psbtbumpfee` to return a PSBT for transactions that contain external inputs. This does not work for bumping in the GUI nor `bumpfee` because these need private keys available to sign and send the transaction. But `psbtbumpfee` returns a psbt, so it is fine to not be able to sign.

  In order to correctly estimate the size of the inputs for coin selection, the fee bumper will use the size of the inputs of the transaction being bumped. Because the sizes of signatures are not guaranteed, for external inputs, the fee bumper will verify the scripts with a special SignatureChecker which will compute the weight of all of the signatures in that input, and compute their weights if those signatures were maximally sized. This allows the fee bumper to obtain a max size estimate for each external input.

  Builds on #23201 as it relies on the ability to pass weights in to coin selection.

  Closes #23189

ACKs for top commit:
  ishaanam:
    reACK c3b099ace031758cafeec08c38bedbf717d6b7fe
  t-bast:
    Re-ran my tests agains https://github.com/bitcoin/bitcoin/pull/23202/commits/c3b099ace031758cafeec08c38bedbf717d6b7fe, ACK

Tree-SHA512: 40016ec52d351430977579cfa2694c7e6764f42c9ce09d3a6f1753b767f86053f296d9de988248df033be6d725d67badbf2a5ef82c8ace23c61487729b7691e5

1 files changed, 21 insertions, 2 deletions

diff --git a/test/functional/wallet_bumpfee.py b/test/functional/wallet_bumpfee.py
index 9a481b290b..79be016b72 100755
--- a/test/functional/wallet_bumpfee.py
+++ b/test/functional/wallet_bumpfee.py
@@ -86,7 +86,7 @@ class BumpFeeTest(BitcoinTestFramework):
         self.test_invalid_parameters(rbf_node, peer_node, dest_address)
         test_segwit_bumpfee_succeeds(self, rbf_node, dest_address)
         test_nonrbf_bumpfee_fails(self, peer_node, dest_address)
-        test_notmine_bumpfee_fails(self, rbf_node, peer_node, dest_address)
+        test_notmine_bumpfee(self, rbf_node, peer_node, dest_address)
         test_bumpfee_with_descendant_fails(self, rbf_node, rbf_node_address, dest_address)
         test_dust_to_fee(self, rbf_node, dest_address)
         test_watchonly_psbt(self, peer_node, rbf_node, dest_address)
@@ -232,7 +232,7 @@ def test_nonrbf_bumpfee_fails(self, peer_node, dest_address):
     self.clear_mempool()
 
 
-def test_notmine_bumpfee_fails(self, rbf_node, peer_node, dest_address):
+def test_notmine_bumpfee(self, rbf_node, peer_node, dest_address):
     self.log.info('Test that it cannot bump fee if non-owned inputs are included')
     # here, the rbftx has a peer_node coin and then adds a rbf_node input
     # Note that this test depends upon the RPC code checking input ownership prior to change outputs
@@ -250,8 +250,27 @@ def test_notmine_bumpfee_fails(self, rbf_node, peer_node, dest_address):
     signedtx = rbf_node.signrawtransactionwithwallet(rawtx)
     signedtx = peer_node.signrawtransactionwithwallet(signedtx["hex"])
     rbfid = rbf_node.sendrawtransaction(signedtx["hex"])
+    entry = rbf_node.getmempoolentry(rbfid)
+    old_fee = entry["fees"]["base"]
+    old_feerate = int(old_fee / entry["vsize"] * Decimal(1e8))
     assert_raises_rpc_error(-4, "Transaction contains inputs that don't belong to this wallet",
                             rbf_node.bumpfee, rbfid)
+
+    def finish_psbtbumpfee(psbt):
+        psbt = rbf_node.walletprocesspsbt(psbt)
+        psbt = peer_node.walletprocesspsbt(psbt["psbt"])
+        final = rbf_node.finalizepsbt(psbt["psbt"])
+        res = rbf_node.testmempoolaccept([final["hex"]])
+        assert res[0]["allowed"]
+        assert_greater_than(res[0]["fees"]["base"], old_fee)
+
+    self.log.info("Test that psbtbumpfee works for non-owned inputs")
+    psbt = rbf_node.psbtbumpfee(txid=rbfid)
+    finish_psbtbumpfee(psbt["psbt"])
+
+    psbt = rbf_node.psbtbumpfee(txid=rbfid, options={"fee_rate": old_feerate + 10})
+    finish_psbtbumpfee(psbt["psbt"])
+
     self.clear_mempool()