Replace .filter_map with just .filter when possible

If the function or closure passed into .filter_map doesn't do any
filtering or mapping. the method call can be replaced with a simple
.map or .filter. The clippy lint suggests which. In this change, we
can always replace .filter_map with .filter. We also need to change
the closure to return a boolean value, since that's what .filter
expects.

Found by clippy lint unnecessary_filter_map:
https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_filter_map

2 files changed, 8 insertions, 12 deletions

diff --git a/openpgp/src/cert/bundle.rs b/openpgp/src/cert/bundle.rs
index 8fa65131..ab634aa3 100644
--- a/openpgp/src/cert/bundle.rs
+++ b/openpgp/src/cert/bundle.rs
@@ -613,10 +613,10 @@ impl<C> ComponentBundle<C> {
         let check = |revs: &'a [Signature], sec: HashAlgoSecurity|
             -> Option<Vec<&'a Signature>>
         {
-            let revs = revs.iter().filter_map(|rev| {
+            let revs = revs.iter().filter(|rev| {
                 if let Err(err) = policy.signature(rev, sec) {
                     t!("  revocation rejected by caller policy: {}", err);
-                    None
+                    false
                 } else if hard_revocations_are_final
                     && rev.reason_for_revocation()
                     .map(|(r, _)| {
@@ -632,7 +632,7 @@ impl<C> ComponentBundle<C> {
                        .unwrap_or_else(time_zero),
                        rev.reason_for_revocation()
                        .map(|r| (r.0, String::from_utf8_lossy(r.1))));
-                    Some(rev)
+                    true
                 } else if selfsig_creation_time
                     > rev.signature_creation_time().unwrap_or_else(time_zero)
                 {
@@ -641,7 +641,7 @@ impl<C> ComponentBundle<C> {
                     t!("  newer binding signature trumps soft revocation ({:?} > {:?})",
                        selfsig_creation_time,
                        rev.signature_creation_time().unwrap_or_else(time_zero));
-                    None
+                    false
                 } else if let Err(err)
                     = rev.signature_alive(t, time::Duration::new(0, 0))
                 {
@@ -652,13 +652,13 @@ impl<C> ComponentBundle<C> {
                        rev.signature_validity_period()
                            .unwrap_or_else(|| time::Duration::new(0, 0)),
                        err);
-                    None
+                    false
                 } else {
                     t!("  got a revocation: {:?} ({:?})",
                        rev.signature_creation_time().unwrap_or_else(time_zero),
                        rev.reason_for_revocation()
                            .map(|r| (r.0, String::from_utf8_lossy(r.1))));
-                    Some(rev)
+                    true
                 }
             }).collect::<Vec<&Signature>>();
 
diff --git a/openpgp/src/serialize/cert_armored.rs b/openpgp/src/serialize/cert_armored.rs
index ab22ec51..83b68479 100644
--- a/openpgp/src/serialize/cert_armored.rs
+++ b/openpgp/src/serialize/cert_armored.rs
@@ -37,12 +37,8 @@ impl Cert {
         // Create a header per userid.
         let mut headers: Vec<String> = self.userids().with_policy(p, None)
             // Ignore revoked userids.
-            .filter_map(|uidb| {
-                if let RevocationStatus::Revoked(_) = uidb.revocation_status() {
-                    None
-                } else {
-                    Some(uidb)
-                }
+            .filter(|uidb| {
+                !matches!(uidb.revocation_status(), RevocationStatus::Revoked(_))
             // Ignore userids with non-printable characters.
             }).filter_map(|uidb| {
                 let value = str::from_utf8(uidb.userid().value()).ok()?;