Merge #20466: test: Fix intermittent p2p_fingerprint issue

fad7be5 test: Fix intermittent p2p_finerprint issue (MarcoFalke)

Pull request description:

  A single sync_with_ping can't be used to drop a block announcement, as the block might be sent *after* the ping has been responded to.

  Fix that by waiting for the block.

ACKs for top commit:
  theStack:
    ACK fad7be5

Tree-SHA512: d43ba9d07273486858f65a26326cc6637ef743bf7b400e5048ba7eac266fb1893283e6503dd49f179caa1abab2977315fb70ba9fba34be9a817a74259d8e4034

Author: MarcoFalke

test/functional/p2p_fingerprint.py

@@ -98,9 +98,9 @@ def run_test(self):
 
         # Longest chain is extended so stale is much older than chain tip
         self.nodes[0].setmocktime(0)
-        self.nodes[0].generatetoaddress(1, self.nodes[0].get_deterministic_priv_key().address)
+        block_hash = int(self.nodes[0].generatetoaddress(1, self.nodes[0].get_deterministic_priv_key().address)[-1], 16)
         assert_equal(self.nodes[0].getblockcount(), 14)
-        node0.sync_with_ping()
+        node0.wait_for_block(block_hash, timeout=3)
 
         # Request for very old stale block should now fail
         with p2p_lock:
@@ -128,5 +128,6 @@ def run_test(self):
         self.send_header_request(block_hash, node0)
         node0.wait_for_header(hex(block_hash), timeout=3)
 
+
 if __name__ == '__main__':
     P2PFingerprintTest().main()