Merge bitcoin#17522: test: Wait until mempool is loaded in wallet_abandonconflict

dddd09e test: Wait until mempool is loaded in wallet_abandonconflict (MarcoFalke)

Pull request description:

  This might or might not fix intermittent issues such as https://ci.appveyor.com/project/DrahtBot/bitcoin/builds/28724018#L4091

  I believe the mempool was not loaded fully after the restart, in which case it was not dumped either on the next restart. Thus, the previous mempool was attempted to be loaded a second time, which succeeded and contained the txs.

ACKs for top commit:
  laanwj:
    ACK dddd09e

Tree-SHA512: ab7061f946b5e5388f825dddceadb125f5197b24af3a7fcf1e700235d106a323419a56bfb4d84a2e27442e0de63e540c623b704343d83a98deaab3c02fcbdcbe

Author: MarcoFalke

test/functional/wallet_abandonconflict.py

@@ -18,6 +18,7 @@
     assert_raises_rpc_error,
     connect_nodes,
     disconnect_nodes,
+    wait_until,
 )
 
 
@@ -97,6 +98,7 @@ def run_test(self):
         # TODO: redo with eviction
         self.stop_node(0)
         self.start_node(0, extra_args=["-minrelaytxfee=0.0001"])
+        wait_until(lambda: self.nodes[0].getmempoolinfo()['loaded'])
 
         # Verify txs no longer in either node's mempool
         assert_equal(len(self.nodes[0].getrawmempool()), 0)
@@ -124,6 +126,8 @@ def run_test(self):
         # Verify that even with a low min relay fee, the tx is not reaccepted from wallet on startup once abandoned
         self.stop_node(0)
         self.start_node(0, extra_args=["-minrelaytxfee=0.00001"])
+        wait_until(lambda: self.nodes[0].getmempoolinfo()['loaded'])
+
         assert_equal(len(self.nodes[0].getrawmempool()), 0)
         assert_equal(self.nodes[0].getbalance(), balance)
 
@@ -144,6 +148,7 @@ def run_test(self):
         # Remove using high relay fee again
         self.stop_node(0)
         self.start_node(0, extra_args=["-minrelaytxfee=0.0001"])
+        wait_until(lambda: self.nodes[0].getmempoolinfo()['loaded'])
         assert_equal(len(self.nodes[0].getrawmempool()), 0)
         newbalance = self.nodes[0].getbalance()
         assert_equal(newbalance, balance - Decimal("24.9996"))