openpgp: Make test more robust.

  - Currently, the reference time is not set, hence evaluated to the
    current time on demand.  If `now` is at the end of a whole
    second (OpenPGP's time resolution), it may be that we are off by
    one second.  Explicitly set the reference time to avoid this.

  - See #998.

1 files changed, 1 insertions, 0 deletions

diff --git a/openpgp/src/packet/signature.rs b/openpgp/src/packet/signature.rs
index 510134fe..6af03296 100644
--- a/openpgp/src/packet/signature.rs
+++ b/openpgp/src/packet/signature.rs
@@ -4403,6 +4403,7 @@ mod test {
                     SubpacketValue::SignatureExpirationTime(hour_t), true)?)?;
                 Ok(a)
             })?;
+        let sig = sig.set_reference_time(now);
         assert_eq!(sig.signature_expiration_time(), Some(now + hour));
         let sig = sig.set_reference_time(past);
         assert_eq!(sig.signature_expiration_time(), Some(now - hour));