Merge bitcoin/bitcoin#23281: test: check that bumpfee RPC fails for txs with descendants in mempool

4ac8c89 test: check that bumpfee RPC fails for txs with descendants in mempool (Sebastian Falbesoner)

Pull request description:

  This PR adds missing test coverage for the bumpfee RPC error _"Transaction has descendants in the mempool"_,

  https://github.com/bitcoin/bitcoin/blob/6419bdfeb130b20ccfed229d9ba7eca7f385d036/src/wallet/feebumper.cpp#L29-L32

  which is thrown if the bumped tx has descendants in the mempool and is _not_ connected to the bitcoin wallet (for those, the error "Transaction has descendants in the Wallet" is thrown a few lines above). To achieve that, the test framework's MiniWallet is used.

ACKs for top commit:
  brunoerg:
    tACK 4ac8c89
  promag:
    Code review ACK 4ac8c89. Nice stuff!
  lsilva01:
    Tested ACK 4ac8c89 cad756b10c9dee2d9e1405 on Ubuntu 20.04.
  stratospher:
    tested ACK 4ac8c89.

Tree-SHA512: 83e99f9dd2b140c0c0597c0c36c9c948fa334871be40e58a5e004440698d9685661c69bb83ab937d30f692545a3799705f991b31904f2ef31a2fbc3ae1179fa8

Author: MarcoFalke

test/functional/wallet_bumpfee.py

@@ -32,6 +32,8 @@
     assert_greater_than,
     assert_raises_rpc_error,
 )
+from test_framework.wallet import MiniWallet
+
 
 WALLET_PASSPHRASE = "test"
 WALLET_PASSPHRASE_TIMEOUT = 3600
@@ -265,6 +267,14 @@ def test_bumpfee_with_descendant_fails(self, rbf_node, rbf_node_address, dest_ad
     tx = rbf_node.signrawtransactionwithwallet(tx)
     rbf_node.sendrawtransaction(tx["hex"])
     assert_raises_rpc_error(-8, "Transaction has descendants in the wallet", rbf_node.bumpfee, parent_id)
+
+    # create tx with descendant in the mempool by using MiniWallet
+    miniwallet = MiniWallet(rbf_node)
+    parent_id = spend_one_input(rbf_node, miniwallet.get_address())
+    tx = rbf_node.gettransaction(txid=parent_id, verbose=True)['decoded']
+    miniwallet.scan_tx(tx)
+    miniwallet.send_self_transfer(from_node=rbf_node)
+    assert_raises_rpc_error(-8, "Transaction has descendants in the mempool", rbf_node.bumpfee, parent_id)
     self.clear_mempool()