openpgp: Fix use of Error::PolicyViolation.

  - When rejecting a bad critical notation, `Error::PolicyViolation`
    was used incorrectly.  The first field is the thing that is in
    violation of the policy, not a description.

1 files changed, 5 insertions, 3 deletions

diff --git a/openpgp/src/policy.rs b/openpgp/src/policy.rs
index 03d36b02..542fa64f 100644
--- a/openpgp/src/policy.rs
+++ b/openpgp/src/policy.rs
@@ -1489,9 +1489,11 @@ impl<'a> Policy for StandardPolicy<'a> {
                 .context("Policy rejected critical signature subpacket")?;
             if let SubpacketValue::NotationData(n) = csp.value() {
                 if ! self.good_critical_notations.contains(&n.name()) {
-                    return Err(Error::PolicyViolation(
-                        format!("Policy rejected critical notation {:?}",
-                                n.name()), None).into());
+                    return Err(anyhow::Error::from(
+                        Error::PolicyViolation(
+                            format!("Critical notation {:?}",
+                                    n.name()), None))
+                               .context("Policy rejected critical notation"));
                 }
             }
         }