diff options
| -rwxr-xr-x | test/functional/wallet_bumpfee.py | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/test/functional/wallet_bumpfee.py b/test/functional/wallet_bumpfee.py index 38c9807757..2e6a3e0ce4 100755 --- a/test/functional/wallet_bumpfee.py +++ b/test/functional/wallet_bumpfee.py @@ -253,12 +253,18 @@ def test_dust_to_fee(self, rbf_node, dest_address): self.log.info('Test that bumped output that is dust is dropped to fee') rbfid = spend_one_input(rbf_node, dest_address) fulltx = rbf_node.getrawtransaction(rbfid, 1) - # size of transaction (p2wpkh, 1 input, 2 outputs): 141 vbytes - assert_equal(fulltx["vsize"], 141) - # bump with fee_rate of 0.00350000 BTC per 1000 vbytes - # expected bump fee of 141 vbytes * fee_rate 0.00350000 BTC / 1000 vbytes = 0.00049350 BTC - # but dust is dropped, so actual bump fee is 0.00050000 - bumped_tx = rbf_node.bumpfee(rbfid, {"fee_rate": 0.0035}) + # The DER formatting used by Bitcoin to serialize ECDSA signatures means that signatures can have a + # variable size of 70-72 bytes (or possibly even less), with most being 71 or 72 bytes. The signature + # in the witness is divided by 4 for the vsize, so this variance can take the weight across a 4-byte + # boundary. Thus expected transaction size (p2wpkh, 1 input, 2 outputs) is 140-141 vbytes, usually 141. + if not 140 <= fulltx["vsize"] <= 141: + print("Error: Invalid tx vsize of {} (140-141 expected), full tx: {}".format(fulltx["vsize"], fulltx)) + raise AssertionError + # Bump with fee_rate of 0.00350250 BTC per 1000 vbytes to create dust. + # Expected fee is 141 vbytes * fee_rate 0.00350250 BTC / 1000 vbytes = 0.00049385 BTC. + # or occasionally 140 vbytes * fee_rate 0.00350250 BTC / 1000 vbytes = 0.00049035 BTC. + # Dust should be dropped to the fee, so actual bump fee is 0.00050000 BTC. + bumped_tx = rbf_node.bumpfee(rbfid, {"fee_rate": 0.00350250}) full_bumped_tx = rbf_node.getrawtransaction(bumped_tx["txid"], 1) assert_equal(bumped_tx["fee"], Decimal("0.00050000")) assert_equal(len(fulltx["vout"]), 2) |