Merge #16459: [qa] Fix race condition in example_test.py

d9ab0ff [qa] Fix race condition in example_test.py (Suhas Daftuar)

Pull request description:

  There's a race between sending a getdata for a bunch of blocks with the node receiving those blocks from a peer, which could cause test failure.  Fix this.

ACKs for top commit:
  MarcoFalke:
    ACK d9ab0ff
  laanwj:
    ACK  d9ab0ff
  promag:
    ACK d9ab0ff.

Tree-SHA512: c891f209eb2492f44e47da52ee6df950ff874ae26d2739011aca940d1caff6cedbac032b6509adbed07044c14fd711ba9d4d0e35c0f70bb2691f2ea4a46672ed

Author: MarcoFalke

test/functional/example_test.py

@@ -186,12 +186,15 @@ def run_test(self):
         self.log.info("Connect node2 and node1")
         connect_nodes(self.nodes[1], 2)
 
+        self.log.info("Wait for node2 to receive all the blocks from node1")
+        self.sync_all()
+
         self.log.info("Add P2P connection to node2")
         self.nodes[0].disconnect_p2ps()
 
         self.nodes[2].add_p2p_connection(BaseNode())
 
-        self.log.info("Wait for node2 reach current tip. Test that it has propagated all the blocks to us")
+        self.log.info("Test that node2 propagates all the blocks to us")
 
         getdata_request = msg_getdata()
         for block in blocks: