openpgp: Don't implement Default for the Bitflags types.

  - See #525.

18 files changed, 87 insertions, 93 deletions

diff --git a/autocrypt/src/cert.rs b/autocrypt/src/cert.rs
index d0b1fdc1..7bbe2545 100644
--- a/autocrypt/src/cert.rs
+++ b/autocrypt/src/cert.rs
@@ -28,11 +28,11 @@ pub fn cert_builder<'a, V, U>(version: V, userid: Option<U>)
             Autocrypt::V1_1 => CipherSuite::Cv25519,
         })
         .set_primary_key_flags(
-            KeyFlags::default()
+            KeyFlags::empty()
                 .set_certification()
                 .set_signing())
         .add_subkey(
-            KeyFlags::default()
+            KeyFlags::empty()
                 .set_transport_encryption()
                 .set_storage_encryption(),
             None,
diff --git a/openpgp-ffi/src/packet/signature.rs b/openpgp-ffi/src/packet/signature.rs
index fdab2d4f..b6ee4061 100644
--- a/openpgp-ffi/src/packet/signature.rs
+++ b/openpgp-ffi/src/packet/signature.rs
@@ -11,6 +11,7 @@ use libc::time_t;
 use libc::c_uint;
 
 extern crate sequoia_openpgp as openpgp;
+use openpgp::types::KeyFlags;
 use super::Packet;
 use super::super::fingerprint::Fingerprint;
 use super::super::keyid::KeyID;
@@ -71,14 +72,14 @@ fn pgp_signature_issuer_fingerprint(sig: *const Signature)
 /// make certifications.
 #[::sequoia_ffi_macros::extern_fn] #[no_mangle] pub extern "C"
 fn pgp_signature_for_certification(sig: *const Signature) -> bool {
-    sig.ref_raw().key_flags().unwrap_or_default().for_certification()
+    sig.ref_raw().key_flags().unwrap_or_else(KeyFlags::empty).for_certification()
 }
 
 /// Returns whether the KeyFlags indicates that the key can be used to
 /// make signatures.
 #[::sequoia_ffi_macros::extern_fn] #[no_mangle] pub extern "C"
 fn pgp_signature_for_signing(sig: *const Signature) -> bool {
-    sig.ref_raw().key_flags().unwrap_or_default().for_signing()
+    sig.ref_raw().key_flags().unwrap_or_else(KeyFlags::empty).for_signing()
 }
 
 /// Returns whether the KeyFlags indicates that the key can be used to
@@ -86,35 +87,35 @@ fn pgp_signature_for_signing(sig: *const Signature) -> bool {
 #[::sequoia_ffi_macros::extern_fn] #[no_mangle] pub extern "C"
 fn pgp_signature_for_transport_encryption(sig: *const Signature)
                                            -> bool {
-    sig.ref_raw().key_flags().unwrap_or_default().for_transport_encryption()
+    sig.ref_raw().key_flags().unwrap_or_else(KeyFlags::empty).for_transport_encryption()
 }
 
 /// Returns whether the KeyFlags indicates that the key can be used to
 /// encrypt data at rest.
 #[::sequoia_ffi_macros::extern_fn] #[no_mangle] pub extern "C"
 fn pgp_signature_for_storage_encryption(sig: *const Signature) -> bool {
-    sig.ref_raw().key_flags().unwrap_or_default().for_storage_encryption()
+    sig.ref_raw().key_flags().unwrap_or_else(KeyFlags::empty).for_storage_encryption()
 }
 
 /// Returns whether the KeyFlags indicates that the key can be used
 /// for authentication.
 #[::sequoia_ffi_macros::extern_fn] #[no_mangle] pub extern "C"
 fn pgp_signature_for_authentication(sig: *const Signature) -> bool {
-    sig.ref_raw().key_flags().unwrap_or_default().for_authentication()
+    sig.ref_raw().key_flags().unwrap_or_else(KeyFlags::empty).for_authentication()
 }
 
 /// Returns whether the KeyFlags indicates that the key is a split
 /// key.
 #[::sequoia_ffi_macros::extern_fn] #[no_mangle] pub extern "C"
 fn pgp_signature_is_split_key(sig: *const Signature) -> bool {
-    sig.ref_raw().key_flags().unwrap_or_default().is_split_key()
+    sig.ref_raw().key_flags().unwrap_or_else(KeyFlags::empty).is_split_key()
 }
 
 /// Returns whether the KeyFlags indicates that the key is a group
 /// key.
 #[::sequoia_ffi_macros::extern_fn] #[no_mangle] pub extern "C"
 fn pgp_signature_is_group_key(sig: *const Signature) -> bool {
-    sig.ref_raw().key_flags().unwrap_or_default().is_group_key()
+    sig.ref_raw().key_flags().unwrap_or_else(KeyFlags::empty).is_group_key()
 }
 
 
diff --git a/openpgp/examples/encrypt-for.rs b/openpgp/examples/encrypt-for.rs
index e1b580ef..80fe52e5 100644
--- a/openpgp/examples/encrypt-for.rs
+++ b/openpgp/examples/encrypt-for.rs
@@ -24,8 +24,8 @@ fn main() {
     }
 
     let mode = match args[1].as_ref() {
-        "at-rest" => KeyFlags::default().set_storage_encryption(),
-        "for-transport" => KeyFlags::default().set_transport_encryption(),
+        "at-rest" => KeyFlags::empty().set_storage_encryption(),
+        "for-transport" => KeyFlags::empty().set_transport_encryption(),
         x => panic!("invalid mode: {:?}, \
                      must be either 'at-rest' or 'for-transport'",
                     x),
diff --git a/openpgp/examples/pad.rs b/openpgp/examples/pad.rs
index d0c7a759..5d31d969 100644
--- a/openpgp/examples/pad.rs
+++ b/openpgp/examples/pad.rs
@@ -24,8 +24,8 @@ fn main() {
     }
 
     let mode = match args[1].as_ref() {
-        "at-rest" => KeyFlags::default().set_storage_encryption(),
-        "for-transport" => KeyFlags::default().set_transport_encryption(),
+        "at-rest" => KeyFlags::empty().set_storage_encryption(),
+        "for-transport" => KeyFlags::empty().set_transport_encryption(),
         x => panic!("invalid mode: {:?}, \
                      must be either 'at-rest' or 'for-transport'",
                     x),
diff --git a/openpgp/src/cert/amalgamation/key.rs b/openpgp/src/cert/amalgamation/key.rs
index 78f34f5d..beea857d 100644
--- a/openpgp/src/cert/amalgamation/key.rs
+++ b/openpgp/src/cert/amalgamation/key.rs
@@ -1548,7 +1548,7 @@ impl<'a, P, R, R2> ValidKeyAmalgamation<'a, P, R, R2>
     pub fn has_any_key_flag<F>(&self, flags: F) -> bool
         where F: Borrow<KeyFlags>
     {
-        let our_flags = self.key_flags().unwrap_or_default();
+        let our_flags = self.key_flags().unwrap_or_else(KeyFlags::empty);
         !(&our_flags & flags.borrow()).is_empty()
     }
 
@@ -1599,7 +1599,7 @@ impl<'a, P, R, R2> ValidKeyAmalgamation<'a, P, R, R2>
     /// [Section 12.1 of RFC 4880]: https://tools.ietf.org/html/rfc4880#section-5.2.3.21
     /// [`ValidKeyAmalgamation::key_flags`]: #method.key_flags
     pub fn for_certification(&self) -> bool {
-        self.has_any_key_flag(KeyFlags::default().set_certification())
+        self.has_any_key_flag(KeyFlags::empty().set_certification())
     }
 
     /// Returns whether the key is signing capable.
@@ -1632,7 +1632,7 @@ impl<'a, P, R, R2> ValidKeyAmalgamation<'a, P, R, R2>
     ///
     /// [`ValidKeyAmalgamation::key_flags`]: #method.key_flags
     pub fn for_signing(&self) -> bool {
-        self.has_any_key_flag(KeyFlags::default().set_signing())
+        self.has_any_key_flag(KeyFlags::empty().set_signing())
     }
 
     /// Returns whether the key is authentication capable.
@@ -1666,7 +1666,7 @@ impl<'a, P, R, R2> ValidKeyAmalgamation<'a, P, R, R2>
     /// [`ValidKeyAmalgamation::key_flags`]: #method.key_flags
     pub fn for_authentication(&self) -> bool
     {
-        self.has_any_key_flag(KeyFlags::default().set_authentication())
+        self.has_any_key_flag(KeyFlags::empty().set_authentication())
     }
 
     /// Returns whether the key is storage-encryption capable.
@@ -1713,7 +1713,7 @@ impl<'a, P, R, R2> ValidKeyAmalgamation<'a, P, R, R2>
     /// [`ValidKeyAmalgamation::key_flags`]: #method.key_flags
     pub fn for_storage_encryption(&self) -> bool
     {
-        self.has_any_key_flag(KeyFlags::default().set_storage_encryption())
+        self.has_any_key_flag(KeyFlags::empty().set_storage_encryption())
     }
 
     /// Returns whether the key is transport-encryption capable.
@@ -1760,7 +1760,7 @@ impl<'a, P, R, R2> ValidKeyAmalgamation<'a, P, R, R2>
     /// [`ValidKeyAmalgamation::key_flags`]: #method.key_flags
     pub fn for_transport_encryption(&self) -> bool
     {
-        self.has_any_key_flag(KeyFlags::default().set_transport_encryption())
+        self.has_any_key_flag(KeyFlags::empty().set_transport_encryption())
     }
 
     /// Returns how long the key is live.
diff --git a/openpgp/src/cert/amalgamation/key/iter.rs b/openpgp/src/cert/amalgamation/key/iter.rs
index f1d66c0c..d14fdc0b 100644
--- a/openpgp/src/cert/amalgamation/key/iter.rs
+++ b/openpgp/src/cert/amalgamation/key/iter.rs
@@ -947,7 +947,7 @@ impl<'a, P, R> ValidKeyAmalgamationIter<'a, P, R>
     ///   [Section 12.1 of RFC 4880]: https://tools.ietf.org/html/rfc4880#section-5.2.3.21
     ///   [`ValidKeyAmalgamation::key_flags`]: struct.ValidKeyAmalgamation.html#method.key_flags
     pub fn for_certification(self) -> Self {
-        self.key_flags(KeyFlags::default().set_certification())
+        self.key_flags(KeyFlags::empty().set_certification())
     }
 
     /// Returns signing-capable keys.
@@ -990,7 +990,7 @@ impl<'a, P, R> ValidKeyAmalgamationIter<'a, P, R>
     ///
     ///   [`ValidKeyAmalgamation::for_signing`]: struct.ValidKeyAmalgamation.html#method.for_signing
     pub fn for_signing(self) -> Self {
-        self.key_flags(KeyFlags::default().set_signing())
+        self.key_flags(KeyFlags::empty().set_signing())
     }
 
     /// Returns authentication-capable keys.
@@ -1033,7 +1033,7 @@ impl<'a, P, R> ValidKeyAmalgamationIter<'a, P, R>
     ///
     ///   [`ValidKeyAmalgamation::for_authentication`]: struct.ValidKeyAmalgamation.html#method.for_authentication
     pub fn for_authentication(self) -> Self {
-        self.key_flags(KeyFlags::default().set_authentication())
+        self.key_flags(KeyFlags::empty().set_authentication())
     }
 
     /// Returns encryption-capable keys for data at rest.
@@ -1076,7 +1076,7 @@ impl<'a, P, R> ValidKeyAmalgamationIter<'a, P, R>
     ///
     ///   [`ValidKeyAmalgamation::for_storage_encryption`]: struct.ValidKeyAmalgamation.html#method.for_storage_encryption
     pub fn for_storage_encryption(self) -> Self {
-        self.key_flags(KeyFlags::default().set_storage_encryption())
+        self.key_flags(KeyFlags::empty().set_storage_encryption())
     }
 
     /// Returns encryption-capable keys for data in transit.
@@ -1119,7 +1119,7 @@ impl<'a, P, R> ValidKeyAmalgamationIter<'a, P, R>
     ///
     ///   [`ValidKeyAmalgamation::for_transport_encryption`]: struct.ValidKeyAmalgamation.html#method.for_transport_encryption
     pub fn for_transport_encryption(self) -> Self {
-        self.key_flags(KeyFlags::default().set_transport_encryption())
+        self.key_flags(KeyFlags::empty().set_transport_encryption())
     }
 
     /// Returns keys that are alive.
@@ -1533,7 +1533,7 @@ mod test {
         let p = &P::new();
         let (cert, _) = CertBuilder::new()
             .generate().unwrap();
-        let flags = KeyFlags::default().set_transport_encryption();
+        let flags = KeyFlags::empty().set_transport_encryption();
 
         assert_eq!(cert.keys().with_policy(p, None).key_flags(flags).count(), 0);
     }
@@ -1544,7 +1544,7 @@ mod test {
         let (cert, _) = CertBuilder::new()
             .add_transport_encryption_subkey()
             .generate().unwrap();
-        let flags = KeyFlags::default().set_transport_encryption();
+        let flags = KeyFlags::empty().set_transport_encryption();
 
         assert_eq!(cert.keys().with_policy(p, None).key_flags(flags).count(), 1);
     }
@@ -1556,7 +1556,7 @@ mod test {
             .add_transport_encryption_subkey()
             .add_signing_subkey()
             .generate().unwrap();
-        let flags = KeyFlags::default().set_transport_encryption();
+        let flags = KeyFlags::empty().set_transport_encryption();
 
         assert_eq!(cert.keys().with_policy(p, None).key_flags(flags).count(), 1);
     }
@@ -1567,7 +1567,7 @@ mod test {
         let (cert, _) = CertBuilder::new()
             .add_transport_encryption_subkey()
             .generate().unwrap();
-        let flags = KeyFlags::default().set_transport_encryption();
+        let flags = KeyFlags::empty().set_transport_encryption();
 
         let now = SystemTime::now()
             - std::time::Duration::new(52 * 7 * 24 * 60 * 60, 0);
@@ -1581,7 +1581,7 @@ mod test {
         let (cert, _) = CertBuilder::new()
             .add_certification_subkey()
             .generate().unwrap();
-        let flags = KeyFlags::default().set_certification();
+        let flags = KeyFlags::empty().set_certification();
 
         assert_eq!(cert.keys().with_policy(p, None).key_flags(flags).count(),
                    2);
@@ -1611,7 +1611,7 @@ mod test {
                        .for_signing().count(),
                    1);
         assert_eq!(cert.keys().with_policy(p, None).alive().revoked(false)
-                       .key_flags(KeyFlags::default().set_authentication())
+                       .key_flags(KeyFlags::empty().set_authentication())
                        .count(),
                    1);
     }
diff --git a/openpgp/src/cert/bindings.rs b/openpgp/src/cert/bindings.rs
index a5a32976..1884fe72 100644
--- a/openpgp/src/cert/bindings.rs
+++ b/openpgp/src/cert/bindings.rs
@@ -38,7 +38,7 @@ impl<P: key::KeyParts> Key<P, key::SubordinateRole> {
     ///     .parts_into_secret()?.into_keypair()?;
     ///
     /// // Let's add an encryption subkey.
-    /// let flags = KeyFlags::default().set_storage_encryption();
+    /// let flags = KeyFlags::empty().set_storage_encryption();
     /// assert_eq!(cert.keys().with_policy(p, None).alive().revoked(false)
     ///                .key_flags(&flags).count(),
     ///            0);
@@ -146,7 +146,7 @@ impl UserID {
     /// # fn f() -> Result<()> {
     /// // Generate a Cert, and create a keypair from the primary key.
     /// let (alice, _) = CertBuilder::new()
-    ///     .set_primary_key_flags(KeyFlags::default().set_certification())
+    ///     .set_primary_key_flags(KeyFlags::empty().set_certification())
     ///     .add_userid("alice@example.org")
     ///     .generate()?;
     /// let mut keypair = alice.primary_key().key().clone()
@@ -154,7 +154,7 @@ impl UserID {
     ///
     /// // Generate a Cert for Bob.
     /// let (bob, _) = CertBuilder::new()
-    ///     .set_primary_key_flags(KeyFlags::default().set_certification())
+    ///     .set_primary_key_flags(KeyFlags::empty().set_certification())
     ///     .add_userid("bob@example.org")
     ///     .generate()?;
     ///
@@ -294,7 +294,7 @@ impl UserAttribute {
     ///         Image::Private(100, vec![0, 1, 2].into_boxed_slice())),
     /// ])?;
     /// let (bob, _) = CertBuilder::new()
-    ///     .set_primary_key_flags(KeyFlags::default().set_certification())
+    ///     .set_primary_key_flags(KeyFlags::empty().set_certification())
     ///     .add_user_attribute(user_attr)
     ///     .generate()?;
     ///
diff --git a/openpgp/src/cert/builder.rs b/openpgp/src/cert/builder.rs
index 0750143a..1f725732 100644
--- a/openpgp/src/cert/builder.rs
+++ b/openpgp/src/cert/builder.rs
@@ -211,7 +211,7 @@ impl CertBuilder {
             creation_time: None,
             ciphersuite: CipherSuite::default(),
             primary: KeyBlueprint{
-                flags: KeyFlags::default().set_certification(),
+                flags: KeyFlags::empty().set_certification(),
                 validity: None,
                 ciphersuite: None,
             },
@@ -254,7 +254,7 @@ impl CertBuilder {
             creation_time: None,
             ciphersuite: ciphersuite.into().unwrap_or(Default::default()),
             primary: KeyBlueprint {
-                flags: KeyFlags::default()
+                flags: KeyFlags::empty()
                     .set_certification()
                     .set_signing(),
                 validity: Some(time::Duration::new(3 * 52 * 7 * 24 * 60 * 60, 0)),
@@ -262,7 +262,7 @@ impl CertBuilder {
             },
             subkeys: vec![
                 KeyBlueprint {
-                    flags: KeyFlags::default()
+                    flags: KeyFlags::empty()
                         .set_transport_encryption()
                         .set_storage_encryption(),
                     validity: None,
@@ -551,7 +551,7 @@ impl CertBuilder {
     /// # }
     /// ```
     pub fn add_signing_subkey(self) -> Self {
-        self.add_subkey(KeyFlags::default().set_signing(), None, None)
+        self.add_subkey(KeyFlags::empty().set_signing(), None, None)
     }
 
     /// Adds a subkey suitable for transport encryption.
@@ -589,7 +589,7 @@ impl CertBuilder {
     /// # }
     /// ```
     pub fn add_transport_encryption_subkey(self) -> Self {
-        self.add_subkey(KeyFlags::default().set_transport_encryption(),
+        self.add_subkey(KeyFlags::empty().set_transport_encryption(),
                         None, None)
     }
 
@@ -628,7 +628,7 @@ impl CertBuilder {
     /// # }
     /// ```
     pub fn add_storage_encryption_subkey(self) -> Self {
-        self.add_subkey(KeyFlags::default().set_storage_encryption(),
+        self.add_subkey(KeyFlags::empty().set_storage_encryption(),
                         None, None)
     }
 
@@ -667,7 +667,7 @@ impl CertBuilder {
     /// # }
     /// ```
     pub fn add_certification_subkey(self) -> Self {
-        self.add_subkey(KeyFlags::default().set_certification(), None, None)
+        self.add_subkey(KeyFlags::empty().set_certification(), None, None)
     }
 
     /// Adds an authentication-capable subkey.
@@ -705,7 +705,7 @@ impl CertBuilder {
     /// # }
     /// ```
     pub fn add_authentication_subkey(self) -> Self {
-        self.add_subkey(KeyFlags::default().set_authentication(), None, None)
+        self.add_subkey(KeyFlags::empty().set_authentication(), None, None)
     }
 
     /// Adds a custom subkey.
@@ -1062,7 +1062,7 @@ impl CertBuilder {
     {
         let mut key = self.primary.ciphersuite
             .unwrap_or(self.ciphersuite)
-            .generate_key(&KeyFlags::default().set_certification())?;
+            .generate_key(&KeyFlags::empty().set_certification())?;
         key.set_creation_time(creation_time)?;
         let mut sig = signature::SignatureBuilder::new(SignatureType::DirectKey)
             // GnuPG wants at least a 512-bit hash for P521 keys.
@@ -1182,7 +1182,7 @@ mod tests {
         let p = &P::new();
         let (cert1, _) = CertBuilder::new()
             .set_cipher_suite(CipherSuite::Cv25519)
-            .set_primary_key_flags(KeyFlags::default())
+            .set_primary_key_flags(KeyFlags::empty())
             .add_transport_encryption_subkey()
             .generate().unwrap();
         assert!(cert1.primary_key().with_policy(p, None).unwrap().for_certification());
@@ -1193,8 +1193,8 @@ mod tests {
     fn gen_wired_subkeys() {
         let (cert1, _) = CertBuilder::new()
             .set_cipher_suite(CipherSuite::Cv25519)
-            .set_primary_key_flags(KeyFlags::default())
-            .add_subkey(KeyFlags::default().set_certification(), None, None)
+            .set_primary_key_flags(KeyFlags::empty())
+            .add_subkey(KeyFlags::empty().set_certification(), None, None)
             .generate().unwrap();
         let sig_pkts = cert1.subkeys().next().unwrap().bundle().self_signatures[0].hashed_area();
 
@@ -1265,9 +1265,9 @@ mod tests {
         let (cert,_) = CertBuilder::new()
             .set_creation_time(now)
             .set_validity_period(600 * s)
-            .add_subkey(KeyFlags::default().set_signing(),
+            .add_subkey(KeyFlags::empty().set_signing(),
                         300 * s, None)
-            .add_subkey(KeyFlags::default().set_authentication(),
+            .add_subkey(KeyFlags::empty().set_authentication(),
                         None, None)
             .generate().unwrap();
 
diff --git a/openpgp/src/cert/mod.rs b/openpgp/src/cert/mod.rs
index f932292a..75695e82 100644
--- a/openpgp/src/cert/mod.rs
+++ b/openpgp/src/cert/mod.rs
@@ -4073,7 +4073,7 @@ mod test {
         let (bind1, rev1, bind2, rev2) = {
             let bind1 = signature::SignatureBuilder::new(SignatureType::DirectKey)
                 .set_features(&Features::sequoia()).unwrap()
-                .set_key_flags(&KeyFlags::default()).unwrap()
+                .set_key_flags(&KeyFlags::empty()).unwrap()
                 .set_signature_creation_time(t1).unwrap()
                 .set_key_validity_period(Some(time::Duration::new(10 * 52 * 7 * 24 * 60 * 60, 0))).unwrap()
                 .set_preferred_hash_algorithms(vec![HashAlgorithm::SHA512]).unwrap()
@@ -4087,7 +4087,7 @@ mod test {
 
             let bind2 = signature::SignatureBuilder::new(SignatureType::DirectKey)
                 .set_features(&Features::sequoia()).unwrap()
-                .set_key_flags(&KeyFlags::default()).unwrap()
+                .set_key_flags(&KeyFlags::empty()).unwrap()
                 .set_signature_creation_time(t3).unwrap()
                 .set_key_validity_period(Some(time::Duration::new(10 * 52 * 7 * 24 * 60 * 60, 0))).unwrap()
                 .set_preferred_hash_algorithms(vec![HashAlgorithm::SHA512]).unwrap()
@@ -4751,7 +4751,7 @@ Pu1xwz57O4zo1VYf6TqHJzVC3OMvMUM2hhdecMUe5x6GorNaj6g=
             for i in 0..N {
                 let binding = signature::SignatureBuilder::new(SignatureType::DirectKey)
                     .set_features(&Features::sequoia()).unwrap()
-                    .set_key_flags(&KeyFlags::default()).unwrap()
+                    .set_key_flags(&KeyFlags::empty()).unwrap()
                     .set_signature_creation_time(t1).unwrap()
                     // Vary this...
                     .set_key_validity_period(Some(
@@ -5017,7 +5017,7 @@ Pu1xwz57O4zo1VYf6TqHJzVC3OMvMUM2hhdecMUe5x6GorNaj6g=
             key::Key4::generate_ecc(false, Curve::Cv25519)?.into();
         let subkey_pub = subkey_sec.clone().take_secret().0;
         let builder = signature::SignatureBuilder::new(SignatureType::SubkeyBinding)
-            .set_key_flags(&KeyFlags::default()
+            .set_key_flags(&KeyFlags::empty()
                            .set_transport_encryption())?;
         let binding = subkey_sec.bind(&mut primary_pair, &cert, builder)?;
 
diff --git a/openpgp/src/packet/signature/subpacket.rs b/openpgp/src/packet/signature/subpacket.rs
index 875a3a73..c776b0f8 100644
--- a/openpgp/src/packet/signature/subpacket.rs
+++ b/openpgp/src/packet/signature/subpacket.rs
@@ -3018,7 +3018,7 @@ fn accessors() {
         sig.clone().sign_hash(&mut keypair, hash.clone()).unwrap();
     assert_eq!(sig_.preferred_compression_algorithms(), Some(&pref[..]));
 
-    let pref = KeyServerPreferences::default()
+    let pref = KeyServerPreferences::empty()
         .set_no_modify();
     sig = sig.set_key_server_preferences(pref.clone()).unwrap();
     let sig_ =
@@ -3039,7 +3039,7 @@ fn accessors() {
         sig.clone().sign_hash(&mut keypair, hash.clone()).unwrap();
     assert_eq!(sig_.policy_uri(), Some(&b"foobar"[..]));
 
-    let key_flags = KeyFlags::default()
+    let key_flags = KeyFlags::empty()
         .set_certification()
         .set_signing();
     sig = sig.set_key_flags(&key_flags).unwrap();
@@ -3322,13 +3322,13 @@ fn subpacket_test_2() {
                        )}));
 
         assert_eq!(sig.key_server_preferences().unwrap(),
-                   KeyServerPreferences::default().set_no_modify());
+                   KeyServerPreferences::empty().set_no_modify());
         assert_eq!(sig.subpacket(SubpacketTag::KeyServerPreferences),
                    Some(&Subpacket {
                        length: 2.into(),
                        critical: false,
                        value: SubpacketValue::KeyServerPreferences(
-                           KeyServerPreferences::default().set_no_modify()),
+                           KeyServerPreferences::empty().set_no_modify()),
                    }));
 
         assert!(sig.key_flags().unwrap().for_certification());
@@ -3338,7 +3338,7 @@ fn subpacket_test_2() {
                        length: 2.into(),
                        critical: false,
                        value: SubpacketValue::KeyFlags(
-                           KeyFlags::default().set_certification().set_signing())
+                           KeyFlags::empty().set_certification().set_signing())
                    }));
 
         assert_eq!(sig.features().unwrap(), Features::empty().set_mdc());
diff --git a/openpgp/src/policy.rs b/openpgp/src/policy.rs
index 641a756d..43c448ae 100644
--- a/