test: Return the largest utxo in MiniWallet.get_utxo

2 files changed, 3 insertions, 5 deletions

diff --git a/test/functional/rpc_txoutproof.py b/test/functional/rpc_txoutproof.py
index 3cb11b4c18..2aa3301b89 100755
--- a/test/functional/rpc_txoutproof.py
+++ b/test/functional/rpc_txoutproof.py
@@ -53,7 +53,7 @@ class MerkleBlockTest(BitcoinTestFramework):
         assert_equal(self.nodes[0].verifytxoutproof(self.nodes[0].gettxoutproof([txid1, txid2])), txlist)
         assert_equal(self.nodes[0].verifytxoutproof(self.nodes[0].gettxoutproof([txid1, txid2], blockhash)), txlist)
 
-        txin_spent = miniwallet.get_utxo()  # Get the change from txid2
+        txin_spent = miniwallet.get_utxo(txid=txid2)  # Get the change from txid2
         tx3 = miniwallet.send_self_transfer(from_node=self.nodes[0], utxo_to_spend=txin_spent)
         txid3 = tx3['txid']
         self.generate(self.nodes[0], 1)
diff --git a/test/functional/test_framework/wallet.py b/test/functional/test_framework/wallet.py
index 7de6994735..5f0b573c6e 100644
--- a/test/functional/test_framework/wallet.py
+++ b/test/functional/test_framework/wallet.py
@@ -133,10 +133,9 @@ class MiniWallet:
 
         Args:
         txid: get the first utxo we find from a specific transaction
-
-        Note: Can be used to get the change output immediately after a send_self_transfer
         """
         index = -1  # by default the last utxo
+        self._utxos = sorted(self._utxos, key=lambda k: (k['value'], -k['height']))  # Put the largest utxo last
         if txid:
             utxo = next(filter(lambda utxo: txid == utxo['txid'], self._utxos))
             index = self._utxos.index(utxo)
@@ -172,8 +171,7 @@ class MiniWallet:
 
     def create_self_transfer(self, *, fee_rate=Decimal("0.003"), from_node, utxo_to_spend=None, mempool_valid=True, locktime=0, sequence=0):
         """Create and return a tx with the specified fee_rate. Fee may be exact or at most one satoshi higher than needed."""
-        self._utxos = sorted(self._utxos, key=lambda k: (k['value'], -k['height']))
-        utxo_to_spend = utxo_to_spend or self._utxos.pop()  # Pick the largest utxo (if none provided) and hope it covers the fee
+        utxo_to_spend = utxo_to_spend or self.get_utxo()
         if self._priv_key is None:
             vsize = Decimal(104)  # anyone-can-spend
         else: