Merge #15538: wallet_bumpfee.py: Make sure coin selection produces change

276972cb95 wallet_bumpfee.py: Make sure coin selection produces change (Gregory Sanders)

Pull request description:

  I was hitting the case where change-less transactions were being made.

ACKs for top commit:
  ryanofsky:
    utACK 276972cb95

Tree-SHA512: e2b7a50363daddd3ee749cacfc9d3d685a6c0c7e3e48118bb60131d205bf83ea06cdd66b69dfa3bd4dbb3bbf2b5b673d7225171486ae72fc762e5dabe2c01ef5

test/functional/wallet_bumpfee.py

@@ -304,7 +304,9 @@ def test_unconfirmed_not_spendable(rbf_node, rbf_node_address):
 
 
 def test_bumpfee_metadata(rbf_node, dest_address):
-    rbfid = rbf_node.sendtoaddress(dest_address, Decimal("0.00100000"), "comment value", "to value")
+    assert(rbf_node.getbalance() < 49)
+    rbf_node.generatetoaddress(101, rbf_node.getnewaddress())
+    rbfid = rbf_node.sendtoaddress(dest_address, 49, "comment value", "to value")
     bumped_tx = rbf_node.bumpfee(rbfid)
     bumped_wtx = rbf_node.gettransaction(bumped_tx["txid"])
     assert_equal(bumped_wtx["comment"], "comment value")