Test that offset is applied to all gossiped peers

Use some mock gossiped peers where some have `last_seen` times in the
past and some have times in the future. Check that all the peers have
an offset applied to them by the `validate_addrs` function.

This tests if the offset is applied to all peers that a malicious peer
gossiped to us.

zebra-network/src/peer_set/candidate_set/tests/vectors.rs

@@ -53,6 +53,33 @@ fn doesnt_offset_last_seen_times_in_the_past() {
     assert_eq!(validated_peers, expected_peers);
 }
 
+/// Test that offset is applied to all the addresses if at least one has a `last_seen` time in the
+/// future.
+///
+/// Times that are in the past should be changed as well.
+#[test]
+fn offsets_all_last_seen_times_if_one_is_in_the_future() {
+    let last_seen_limit = DateTime32::now();
+    let last_seen_limit_chrono = last_seen_limit.to_chrono();
+
+    let input_peers = mock_gossiped_peers(vec![
+        last_seen_limit_chrono + Duration::minutes(55),
+        last_seen_limit_chrono - Duration::days(3),
+        last_seen_limit_chrono - Duration::hours(2),
+    ]);
+
+    let validated_peers: Vec<_> = validate_addrs(input_peers, last_seen_limit).collect();
+
+    let expected_offset = Duration::minutes(55);
+    let expected_peers = mock_gossiped_peers(vec![
+        last_seen_limit_chrono + Duration::minutes(55) - expected_offset,
+        last_seen_limit_chrono - Duration::days(3) - expected_offset,
+        last_seen_limit_chrono - Duration::hours(2) - expected_offset,
+    ]);
+
+    assert_eq!(validated_peers, expected_peers);
+}
+
 /// Create a mock list of gossiped [`MetaAddr`]s with the specified `last_seen_times`.
 ///
 /// The IP address and port of the generated ports should not matter for the test.