openpgp: Introduce feature flag for quickcheck.

  - Make quickcheck dependency optional.

  - Make quickcheck a dev-dependency for tests.

  - Fix doctests for
    - cert::ValidCert::user_attributes,
    - cert::builder::CertBuilder::add_user_attribute,
    - cert::revoke::UserAttributeRevocationBuilder
    - cert::revoke::UserAttributeRevocationBuilder::build.
    Doctests do not use cfg(test), so we cannot use quickcheck in there.

30 files changed, 147 insertions, 19 deletions

diff --git a/openpgp/Cargo.toml b/openpgp/Cargo.toml
index 104cb6c5..0698a7bb 100644
--- a/openpgp/Cargo.toml
+++ b/openpgp/Cargo.toml
@@ -33,7 +33,7 @@ lazy_static = "1.3"
 libc = "0.2"
 memsec = "0.5.6"
 nettle = { version = "7", optional = true }
-quickcheck = { version = "0.9", default-features = false }
+quickcheck = { version = "0.9", default-features = false, optional = true }
 rand = { version = "0.7", default-features = false }
 regex = "1"
 thiserror = "1"
@@ -44,6 +44,7 @@ lalrpop = "0.17"
 
 [dev-dependencies]
 rpassword = "=4.0.3"
+quickcheck = { version = "0.9", default-features = false }
 
 [features]
 default = ["compression", "crypto-nettle"]
diff --git a/openpgp/src/armor.rs b/openpgp/src/armor.rs
index f7ece759..2425c804 100644
--- a/openpgp/src/armor.rs
+++ b/openpgp/src/armor.rs
@@ -34,6 +34,8 @@ use std::path::Path;
 use std::cmp;
 use std::str;
 use std::borrow::Cow;
+
+#[cfg(any(test, feature = "quickcheck"))]
 use quickcheck::{Arbitrary, Gen};
 
 use crate::vec_truncate;
@@ -68,6 +70,7 @@ pub enum Kind {
     File,
 }
 
+#[cfg(any(test, feature = "quickcheck"))]
 impl Arbitrary for Kind {
     fn arbitrary<G: Gen>(g: &mut G) -> Self {
         use self::Kind::*;
diff --git a/openpgp/src/cert/builder.rs b/openpgp/src/cert/builder.rs
index 751abb55..4243cb2f 100644
--- a/openpgp/src/cert/builder.rs
+++ b/openpgp/src/cert/builder.rs
@@ -426,7 +426,7 @@ impl CertBuilder {
     /// primary User ID flag set:
     ///
     /// ```
-    /// # use quickcheck::{Arbitrary, StdThreadGen};
+    /// # use openpgp::packet::user_attribute::Subpacket;
     /// use sequoia_openpgp as openpgp;
     /// use openpgp::cert::prelude::*;
     /// use openpgp::packet::prelude::*;
@@ -434,9 +434,11 @@ impl CertBuilder {
     ///
     /// # fn main() -> openpgp::Result<()> {
     /// let p = &StandardPolicy::new();
-    ///
-    /// # let mut gen = StdThreadGen::new(16);
-    /// # let user_attribute : UserAttribute = UserAttribute::arbitrary(&mut gen);
+    /// #
+    /// # // Create some user attribute. Doctests do not pass cfg(test),
+    /// # // so UserAttribute::arbitrary is not available
+    /// # let sp = Subpacket::Unknown(7, vec![7; 7].into_boxed_slice());
+    /// # let user_attribute = UserAttribute::new(&[sp])?;
     ///
     /// let (cert, rev) =
     ///     CertBuilder::new()
@@ -455,7 +457,7 @@ impl CertBuilder {
     /// set:
     ///
     /// ```
-    /// # use quickcheck::{Arbitrary, StdThreadGen};
+    /// # use openpgp::packet::user_attribute::Subpacket;
     /// use sequoia_openpgp as openpgp;
     /// use openpgp::cert::prelude::*;
     /// use openpgp::packet::prelude::*;
@@ -463,9 +465,11 @@ impl CertBuilder {
     ///
     /// # fn main() -> openpgp::Result<()> {
     /// let p = &StandardPolicy::new();
-    ///
-    /// # let mut gen = StdThreadGen::new(16);
-    /// # let user_attribute : UserAttribute = UserAttribute::arbitrary(&mut gen);
+    /// #
+    /// # // Create some user attribute. Doctests do not pass cfg(test),
+    /// # // so UserAttribute::arbitrary is not available
+    /// # let sp = Subpacket::Unknown(7, vec![7; 7].into_boxed_slice());
+    /// # let user_attribute = UserAttribute::new(&[sp])?;
     ///
     /// let (cert, rev) =
     ///     CertBuilder::new()
diff --git a/openpgp/src/cert/mod.rs b/openpgp/src/cert/mod.rs
index 7de9f286..36d54451 100644
--- a/openpgp/src/cert/mod.rs
+++ b/openpgp/src/cert/mod.rs
@@ -3041,10 +3041,10 @@ impl<'a> ValidCert<'a> {
     /// # Examples
     ///
     /// ```
-    /// # use quickcheck::{Arbitrary, StdThreadGen};
     /// use sequoia_openpgp as openpgp;
     /// # use openpgp::cert::prelude::*;
     /// # use openpgp::packet::prelude::*;
+    /// # use openpgp::packet::user_attribute::Subpacket;
     /// use openpgp::policy::StandardPolicy;
     ///
     /// # fn main() -> openpgp::Result<()> {
@@ -3053,8 +3053,12 @@ impl<'a> ValidCert<'a> {
     /// # let (cert, _) =
     /// #     CertBuilder::general_purpose(None, Some("alice@example.org"))
     /// #     .generate()?;
-    /// # let mut gen = StdThreadGen::new(16);
-    /// # let ua : UserAttribute = UserAttribute::arbitrary(&mut gen);
+    /// #
+    /// # // Create some user attribute. Doctests do not pass cfg(test),
+    /// # // so UserAttribute::arbitrary is not available
+    /// # let sp = Subpacket::Unknown(7, vec![7; 7].into_boxed_slice());
+    /// # let ua = UserAttribute::new(&[sp]);
+    /// #
     /// // Add a User Attribute without a self-signature to the certificate.
     /// let cert = cert.merge_packets(ua)?;
     /// assert_eq!(cert.user_attributes().count(), 1);
diff --git a/openpgp/src/cert/revoke.rs b/openpgp/src/cert/revoke.rs
index 50130510..ba46fd1b 100644
--- a/openpgp/src/cert/revoke.rs
+++ b/openpgp/src/cert/revoke.rs
@@ -750,7 +750,7 @@ impl Deref for UserIDRevocationBuilder {
 /// Revoke a User Attribute that is no longer valid:
 ///
 /// ```rust
-/// # use quickcheck::{Arbitrary, StdThreadGen};
+/// # use openpgp::packet::user_attribute::Subpacket;
 /// use sequoia_openpgp as openpgp;
 /// # use openpgp::Result;
 /// use openpgp::cert::prelude::*;
@@ -763,8 +763,10 @@ impl Deref for UserIDRevocationBuilder {
 /// # fn main() -> Result<()> {
 /// let p = &StandardPolicy::new();
 ///
-/// # let mut gen = StdThreadGen::new(16);
-/// # let user_attribute : UserAttribute = UserAttribute::arbitrary(&mut gen);
+/// # // Create some user attribute. Doctests do not pass cfg(test),
+/// # // so UserAttribute::arbitrary is not available
+/// # let sp = Subpacket::Unknown(7, vec![7; 7].into_boxed_slice());
+/// # let user_attribute = UserAttribute::new(&[sp])?;
 /// #
 /// # let (cert, _) = CertBuilder::new()
 /// #     .add_user_attribute(user_attribute)
@@ -905,7 +907,7 @@ impl UserAttributeRevocationBuilder {
     /// valid:
     ///
     /// ```rust
-    /// # use quickcheck::{Arbitrary, StdThreadGen};
+    /// # use openpgp::packet::user_attribute::Subpacket;
     /// use sequoia_openpgp as openpgp;
     /// # use openpgp::Result;
     /// use openpgp::cert::prelude::*;
@@ -918,8 +920,10 @@ impl UserAttributeRevocationBuilder {
     /// # fn main() -> Result<()> {
     /// let p = &StandardPolicy::new();
     ///
-    /// # let mut gen = StdThreadGen::new(16);
-    /// # let user_attribute : UserAttribute = UserAttribute::arbitrary(&mut gen);
+    /// # // Create some user attribute. Doctests do not pass cfg(test),
+    /// # // so UserAttribute::arbitrary is not available
+    /// # let sp = Subpacket::Unknown(7, vec![7; 7].into_boxed_slice());
+    /// # let user_attribute = UserAttribute::new(&[sp])?;
     /// #
     /// # let (cert, _) = CertBuilder::new()
     /// #     .add_user_attribute(user_attribute)
diff --git a/openpgp/src/crypto/mpi.rs b/openpgp/src/crypto/mpi.rs
index 13bc0007..1dd2cd30 100644
--- a/openpgp/src/crypto/mpi.rs
+++ b/openpgp/src/crypto/mpi.rs
@@ -3,7 +3,9 @@
 use std::fmt;
 use std::cmp::Ordering;
 
+#[cfg(any(test, feature = "quickcheck"))]
 use quickcheck::{Arbitrary, Gen};
+#[cfg(any(test, feature = "quickcheck"))]
 use rand::Rng;
 
 use crate::types::{
@@ -184,6 +186,7 @@ impl Hash for MPI {
     }
 }
 
+#[cfg(any(test, feature = "quickcheck"))]
 impl Arbitrary for MPI {
     fn arbitrary<G: Gen>(g: &mut G) -> Self {
         loop {
@@ -409,6 +412,7 @@ impl Hash for PublicKey {
     }
 }
 
+#[cfg(any(test, feature = "quickcheck"))]
 impl Arbitrary for PublicKey {
     fn arbitrary<G: Gen>(g: &mut G) -> Self {
         use self::PublicKey::*;
@@ -678,6 +682,7 @@ impl Hash for SecretKeyMaterial {
     }
 }
 
+#[cfg(any(test, feature = "quickcheck"))]
 impl Arbitrary for SecretKeyMaterial {
     fn arbitrary<G: Gen>(g: &mut G) -> Self {
         match g.gen_range(0, 6) {
@@ -780,6 +785,7 @@ impl Hash for Ciphertext {
     }
 }
 
+#[cfg(any(test, feature = "quickcheck"))]
 impl Arbitrary for Ciphertext {
     fn arbitrary<G: Gen>(g: &mut G) -> Self {
         match g.gen_range(0, 3) {
@@ -865,6 +871,7 @@ impl Hash for Signature {
     }
 }
 
+#[cfg(any(test, feature = "quickcheck"))]
 impl Arbitrary for Signature {
     fn arbitrary<G: Gen>(g: &mut G) -> Self {
         match g.gen_range(0, 4) {
diff --git a/openpgp/src/crypto/s2k.rs b/openpgp/src/crypto/s2k.rs
index 8dff4693..d5553ce4 100644
--- a/openpgp/src/crypto/s2k.rs
+++ b/openpgp/src/crypto/s2k.rs
@@ -14,7 +14,9 @@ use crate::crypto::SessionKey;
 
 use std::fmt;
 
+#[cfg(any(test, feature = "quickcheck"))]
 use quickcheck::{Arbitrary, Gen};
+#[cfg(any(test, feature = "quickcheck"))]
 use rand::Rng;
 
 /// String-to-Key (S2K) specifiers.
@@ -262,6 +264,7 @@ impl fmt::Display for S2K {
     }
 }
 
+#[cfg(any(test, feature = "quickcheck"))]
 impl Arbitrary for S2K {
     fn arbitrary<G: Gen>(g: &mut G) -> Self {
         match g.gen_range(0, 5) {
diff --git a/openpgp/src/crypto/sexp.rs b/openpgp/src/crypto/sexp.rs
index 479fb8e3..17805234 100644
--- a/openpgp/src/crypto/sexp.rs
+++ b/openpgp/src/crypto/sexp.rs
@@ -9,6 +9,8 @@
 use std::convert::TryFrom;
 use std::fmt;
 use std::ops::Deref;
+
+#[cfg(any(test, feature = "quickcheck"))]
 use quickcheck::{Arbitrary, Gen};
 
 use crate::crypto::{self, mpi, SessionKey};
@@ -293,6 +295,7 @@ impl TryFrom<&mpi::Ciphertext> for Sexp {
     }
 }
 
+#[cfg(any(test, feature = "quickcheck"))]
 impl Arbitrary for Sexp {
     fn arbitrary<G: Gen>(g: &mut G) -> Self {
         if f32::arbitrary(g) < 0.7 {
@@ -382,6 +385,7 @@ impl Deref for String_ {
     }
 }
 
+#[cfg(any(test, feature = "quickcheck"))]
 impl Arbitrary for String_ {
     fn arbitrary<G: Gen>(g: &mut G) -> Self {
         if bool::arbitrary(g) {
diff --git a/openpgp/src/fingerprint.rs b/openpgp/src/fingerprint.rs
index 6094229f..a88dafdd 100644
--- a/openpgp/src/fingerprint.rs
+++ b/openpgp/src/fingerprint.rs
@@ -1,4 +1,6 @@
 use std::fmt;
+
+#[cfg(any(test, feature = "quickcheck"))]
 use quickcheck::{Arbitrary, Gen};
 
 /// A long identifier for certificates and keys.
@@ -206,6 +208,7 @@ impl Fingerprint {
     }
 }
 
+#[cfg(any(test, feature = "quickcheck"))]
 impl Arbitrary for Fingerprint {
     fn arbitrary<G: Gen>(g: &mut G) -> Self {
         use rand::Rng;
diff --git a/openpgp/src/keyid.rs b/openpgp/src/keyid.rs
index fb511316..6d8e739f 100644
--- a/openpgp/src/keyid.rs
+++ b/openpgp/src/keyid.rs
@@ -1,4 +1,6 @@
 use std::fmt;
+
+#[cfg(any(test, feature = "quickcheck"))]
 use quickcheck::{Arbitrary, Gen};
 
 use crate::Error;
@@ -247,6 +249,7 @@ impl KeyID {
     }
 }
 
+#[cfg(any(test, feature = "quickcheck"))]
 impl Arbitrary for KeyID {
     fn arbitrary<G: Gen>(g: &mut G) -> Self {
         KeyID::new(u64::arbitrary(g))
diff --git a/openpgp/src/packet/compressed_data.rs b/openpgp/src/packet/compressed_data.rs
index e86d870f..4f379496 100644
--- a/openpgp/src/packet/compressed_data.rs
+++ b/openpgp/src/packet/compressed_data.rs
@@ -1,4 +1,6 @@
 use std::fmt;
+
+#[cfg(any(test, feature = "quickcheck"))]
 use quickcheck::{Arbitrary, Gen};
 
 use crate::packet;
@@ -94,6 +96,7 @@ impl From<CompressedData> for Packet {
     }
 }
 
+#[cfg(any(test, feature = "quickcheck"))]
 impl Arbitrary for CompressedData {
     fn arbitrary<G: Gen>(g: &mut G) -> Self {
         use rand::Rng;
diff --git a/openpgp/src/packet/key.rs b/openpgp/src/packet/key.rs
index 55a9ff60..039c493f 100644
--- a/openpgp/src/packet/key.rs
+++ b/openpgp/src/packet/key.rs
@@ -54,6 +54,8 @@ use std::fmt;
 use std::cmp::Ordering;
 use std::convert::TryInto;
 use std::time;
+
+#[cfg(any(test, feature = "quickcheck"))]
 use quickcheck::{Arbitrary, Gen};
 
 use crate::Error;
@@ -1290,6 +1292,7 @@ impl Encrypted {
     }
 }
 
+#[cfg(any(test, feature = "quickcheck"))]
 impl<P, R> Arbitrary for super::Key<P, R>
     where P: KeyParts, P: Clone,
           R: KeyRole, R: Clone,
@@ -1300,6 +1303,7 @@ impl<P, R> Arbitrary for super::Key<P, R>
     }
 }
 
+#[cfg(any(test, feature = "quickcheck"))]
 impl Arbitrary for Key4<PublicParts, UnspecifiedRole> {
     fn arbitrary<G: Gen>(g: &mut G) -> Self {
         let mpis = mpi::PublicKey::arbitrary(g);
@@ -1316,6 +1320,7 @@ impl Arbitrary for Key4<PublicParts, UnspecifiedRole> {
     }
 }
 
+#[cfg(any(test, feature = "quickcheck"))]
 impl Arbitrary for Key4<SecretParts, UnspecifiedRole> {
     fn arbitrary<G: Gen>(g: &mut G) -> Self {
         use rand::Rng;
diff --git a/openpgp/src/packet/literal.rs b/openpgp/src/packet/literal.rs
index 46e6bfb0..7eb4082b 100644
--- a/openpgp/src/packet/literal.rs
+++ b/openpgp/src/packet/literal.rs
@@ -2,6 +2,8 @@ use std::fmt;
 use std::cmp;
 use std::convert::TryInto;
 use std::time;
+
+#[cfg(any(test, feature = "quickcheck"))]
 use quickcheck::{Arbitrary, Gen};
 
 use crate::types::{DataFormat, Timestamp};
@@ -172,6 +174,7 @@ impl From<Literal> for Packet {
     }
 }
 
+#[cfg(any(test, feature = "quickcheck"))]
 impl Arbitrary for Literal {
     fn arbitrary<G: Gen>(g: &mut G) -> Self {
         let mut l = Literal::new(DataFormat::arbitrary(g));
diff --git a/openpgp/src/packet/marker.rs b/openpgp/src/packet/marker.rs
index 8217901c..728f115b 100644
--- a/openpgp/src/packet/marker.rs
+++ b/openpgp/src/packet/marker.rs
@@ -1,3 +1,4 @@
+#[cfg(any(test, feature = "quickcheck"))]
 use quickcheck::{Arbitrary, Gen};
 
 use crate::packet;
@@ -34,6 +35,7 @@ impl From<Marker> for Packet {
     }
 }
 
+#[cfg(any(test, feature = "quickcheck"))]
 impl Arbitrary for Marker {
     fn arbitrary<G: Gen>(_: &mut G) -> Self {
         Self::default()
diff --git a/openpgp/src/packet/mod.rs b/openpgp/src/packet/mod.rs
index fec3ee2a..3c822df7 100644
--- a/openpgp/src/packet/mod.rs
+++ b/openpgp/src/packet/mod.rs
@@ -161,6 +161,7 @@ use std::ops::{Deref, DerefMut};
 use std::slice;
 use std::iter::IntoIterator;
 
+#[cfg(any(test, feature = "quickcheck"))]
 use quickcheck::{Arbitrary, Gen};
 
 use crate::Error;
@@ -434,6 +435,7 @@ impl<'a> DerefMut for Packet {
     }
 }
 
+#[cfg(any(test, feature = "quickcheck"))]
 impl Arbitrary for Packet {
     fn arbitrary<G: Gen>(g: &mut G) -> Self {
         use rand::Rng;
@@ -479,6 +481,7 @@ pub struct Common {
     dummy: std::marker::PhantomData<()>,
 }
 
+#[cfg(any(test, feature = "quickcheck"))]
 impl Arbitrary for Common {
     fn arbitrary<G: Gen>(_: &mut G) -> Self {
         // XXX: Change if this gets interesting fields.
diff --git a/openpgp/src/packet/one_pass_sig.rs b/openpgp/src/packet/one_pass_sig.rs
index dc40cf64..a6861d6e 100644
--- a/openpgp/src/packet/one_pass_sig.rs
+++ b/openpgp/src/packet/one_pass_sig.rs
@@ -5,6 +5,8 @@
 //!   [Section 5.4 of RFC 4880]: https://tools.ietf.org/html/rfc4880#section-5.4
 
 use std::fmt;
+
+#[cfg(any(test, feature = "quickcheck"))]
 use quickcheck::{Arbitrary, Gen};
 
 use crate::Error;
@@ -166,12 +168,14 @@ impl<'a> std::convert::TryFrom<&'a Signature> for OnePassSig3 {
     }
 }
 
+#[cfg(any(test, feature = "quickcheck"))]
 impl Arbitrary for super::OnePassSig {
     fn arbitrary<G: Gen>(g: &mut G) -> Self {
         OnePassSig3::arbitrary(g).into()
     }
 }
 
+#[cfg(any(test, feature = "quickcheck"))]
 impl Arbitrary for OnePassSig3 {
     fn arbitrary<G: Gen>(g: &mut G) -> Self {
         let mut ops = OnePassSig3::new(SignatureType::arbitrary(g));
diff --git a/openpgp/src/packet/pkesk.rs b/openpgp/src/packet/pkesk.rs
index f92c596e..81c0f9ae 100644
--- a/openpgp/src/packet/pkesk.rs
+++ b/openpgp/src/packet/pkesk.rs
@@ -5,6 +5,7 @@
 //!
 //!   [Section 5.1 of RFC 4880]: https://tools.ietf.org/html/rfc4880#section-5.1
 
+#[cfg(any(test, feature = "quickcheck"))]
 use quickcheck::{Arbitrary, Gen};
 
 use crate::Error;
@@ -189,12 +190,14 @@ impl From<PKESK3> for Packet {
     }
 }
 
+#[cfg(any(test, feature = "quickcheck"))]
 impl Arbitrary for super::PKESK {
     fn arbitrary<G: Gen>(g: &mut G) -> Self {
         PKESK3::arbitrary(g).into()
     }
 }
 
+#[cfg(any(test, feature = "quickcheck"))]
 impl Arbitrary for PKESK3 {
     fn arbitrary<G: Gen>(g: &mut G) -> Self {
         let (ciphertext, pk_algo) = loop {
diff --git a/openpgp/src/packet/signature/mod.rs b/openpgp/src/packet/signature/mod.rs
index d0829a5d..74be7900 100644
--- a/openpgp/src/packet/signature/mod.rs
+++ b/openpgp/src/packet/signature/mod.rs
@@ -2,6 +2,8 @@
 
 use std::fmt;
 use std::ops::{Deref, DerefMut};
+
+#[cfg(any(test, feature = "quickcheck"))]
 use quickcheck::{Arbitrary, Gen};
 
 use crate::Error;
@@ -28,6 +30,7 @@ use crate::packet::signature::subpacket::{
     SubpacketAreas,
 };
 
+#[cfg(any(test, feature = "quickcheck"))]
 /// Like quickcheck::Arbitrary, but bounded.
 trait ArbitraryBounded {
     /// Generates an arbitrary value, but only recurses if `depth >
@@ -35,9 +38,11 @@ trait ArbitraryBounded {
     fn arbitrary_bounded<G: Gen>(g: &mut G, depth: usize) -> Self;
 }
 
+#[cfg(any(test, feature = "quickcheck"))]
 /// Default depth when implementing Arbitrary using ArbitraryBounded.
 const DEFAULT_ARBITRARY_DEPTH: usize = 2;
 
+#[cfg(any(test, feature = "quickcheck"))]
 macro_rules! impl_arbitrary_with_bound {
     ($typ:path) => {
         impl Arbitrary for $typ {
@@ -101,6 +106,7 @@ pub struct SignatureBuilder {
     subpackets: SubpacketAreas,
 }
 
+#[cfg(any(test, feature = "quickcheck"))]
 impl ArbitraryBounded for SignatureBuilder {
     fn arbitrary_bounded<G: Gen>(g: &mut G, depth: usize) -> Self {
         SignatureBuilder {
@@ -115,6 +121,7 @@ impl ArbitraryBounded for SignatureBuilder {
     }
 }
 
+#[cfg(any(test, feature = "quickcheck"))]
 impl_arbitrary_with_bound!(SignatureBuilder);
 
 impl Deref for SignatureBuilder {
@@ -1212,14 +1219,17 @@ impl From<Signature4> for super::Signature {
     }
 }
 
+#[cfg(any(test, feature = "quickcheck"))]
 impl ArbitraryBounded for super: