From d78c94b2a24604f56dcc01aaea013825518c25a5 Mon Sep 17 00:00:00 2001
From: Jack Grigg <jack@z.cash>
Date: Fri, 2 Aug 2019 10:50:32 +0100
Subject: [PATCH 1/8] Move Equihash validator into zcash_primitives

---
 librustzcash/src/rustzcash.rs                                | 3 +--
 zcash_primitives/src/block.rs                                | 2 ++
 {librustzcash/src => zcash_primitives/src/block}/equihash.rs | 0
 3 files changed, 3 insertions(+), 2 deletions(-)
 rename {librustzcash/src => zcash_primitives/src/block}/equihash.rs (100%)

diff --git a/librustzcash/src/rustzcash.rs b/librustzcash/src/rustzcash.rs
index 14b5f00..68b7048 100644
--- a/librustzcash/src/rustzcash.rs
+++ b/librustzcash/src/rustzcash.rs
@@ -45,6 +45,7 @@ use std::ffi::OsString;
 use std::os::windows::ffi::OsStringExt;
 
 use zcash_primitives::{
+    block::equihash,
     merkle_tree::CommitmentTreeWitness,
     note_encryption::sapling_ka_agree,
     primitives::{Diversifier, Note, PaymentAddress, ProofGenerationKey, ViewingKey},
@@ -58,8 +59,6 @@ use zcash_proofs::{
     sapling::{SaplingProvingContext, SaplingVerificationContext},
 };
 
-pub mod equihash;
-
 #[cfg(test)]
 mod tests;
 
diff --git a/zcash_primitives/src/block.rs b/zcash_primitives/src/block.rs
index f2802b4..63e6a05 100644
--- a/zcash_primitives/src/block.rs
+++ b/zcash_primitives/src/block.rs
@@ -6,6 +6,8 @@ use std::ops::Deref;
 
 use crate::serialize::Vector;
 
+pub mod equihash;
+
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
 pub struct BlockHash(pub [u8; 32]);
 
diff --git a/librustzcash/src/equihash.rs b/zcash_primitives/src/block/equihash.rs
similarity index 100%
rename from librustzcash/src/equihash.rs
rename to zcash_primitives/src/block/equihash.rs

From d65fe2cda948195ee48f67923b33935a1a042374 Mon Sep 17 00:00:00 2001
From: Jack Grigg <jack@z.cash>
Date: Fri, 2 Aug 2019 11:13:59 +0100
Subject: [PATCH 2/8] Address various clippy warnings/errors in bellman

---
 bellman/src/domain.rs            | 22 ++++++-----
 bellman/src/gadgets/blake2s.rs   |  4 +-
 bellman/src/gadgets/boolean.rs   | 30 +++++++--------
 bellman/src/gadgets/multieq.rs   |  2 +-
 bellman/src/gadgets/num.rs       | 12 +++---
 bellman/src/gadgets/sha256.rs    |  6 ++-
 bellman/src/gadgets/test/mod.rs  |  6 +--
 bellman/src/gadgets/uint32.rs    | 66 +++++++++++++++-----------------
 bellman/src/groth16/generator.rs |  2 +-
 bellman/src/groth16/mod.rs       | 18 ++++-----
 bellman/src/groth16/verifier.rs  |  2 +-
 bellman/src/lib.rs               |  5 ++-
 bellman/src/multicore.rs         |  2 +-
 13 files changed, 90 insertions(+), 87 deletions(-)

diff --git a/bellman/src/domain.rs b/bellman/src/domain.rs
index 808d2af..d5a86bd 100644
--- a/bellman/src/domain.rs
+++ b/bellman/src/domain.rs
@@ -26,15 +26,19 @@ pub struct EvaluationDomain<E: ScalarEngine, G: Group<E>> {
     minv: E::Fr,
 }
 
-impl<E: ScalarEngine, G: Group<E>> EvaluationDomain<E, G> {
-    pub fn as_ref(&self) -> &[G] {
+impl<E: ScalarEngine, G: Group<E>> AsRef<[G]> for EvaluationDomain<E, G> {
+    fn as_ref(&self) -> &[G] {
         &self.coeffs
     }
+}
 
-    pub fn as_mut(&mut self) -> &mut [G] {
+impl<E: ScalarEngine, G: Group<E>> AsMut<[G]> for EvaluationDomain<E, G> {
+    fn as_mut(&mut self) -> &mut [G] {
         &mut self.coeffs
     }
+}
 
+impl<E: ScalarEngine, G: Group<E>> EvaluationDomain<E, G> {
     pub fn into_coeffs(self) -> Vec<G> {
         self.coeffs
     }
@@ -64,9 +68,9 @@ impl<E: ScalarEngine, G: Group<E>> EvaluationDomain<E, G> {
         coeffs.resize(m, G::group_zero());
 
         Ok(EvaluationDomain {
-            coeffs: coeffs,
-            exp: exp,
-            omega: omega,
+            coeffs,
+            exp,
+            omega,
             omegainv: omega.inverse().unwrap(),
             geninv: E::Fr::multiplicative_generator().inverse().unwrap(),
             minv: E::Fr::from_str(&format!("{}", m))
@@ -291,7 +295,7 @@ fn serial_fft<E: ScalarEngine, T: Group<E>>(a: &mut [T], omega: &E::Fr, log_n: u
 
     let mut m = 1;
     for _ in 0..log_n {
-        let w_m = omega.pow(&[(n / (2 * m)) as u64]);
+        let w_m = omega.pow(&[u64::from(n / (2 * m))]);
 
         let mut k = 0;
         while k < n {
@@ -337,12 +341,12 @@ fn parallel_fft<E: ScalarEngine, T: Group<E>>(
                 let omega_step = omega.pow(&[(j as u64) << log_new_n]);
 
                 let mut elt = E::Fr::one();
-                for i in 0..(1 << log_new_n) {
+                for (i, tmp) in tmp.iter_mut().enumerate() {
                     for s in 0..num_cpus {
                         let idx = (i + (s << log_new_n)) % (1 << log_n);
                         let mut t = a[idx];
                         t.group_mul_assign(&elt);
-                        tmp[i].group_add_assign(&t);
+                        tmp.group_add_assign(&t);
                         elt.mul_assign(&omega_step);
                     }
                     elt.mul_assign(&omega_j);
diff --git a/bellman/src/gadgets/blake2s.rs b/bellman/src/gadgets/blake2s.rs
index c5cee23..beefe09 100644
--- a/bellman/src/gadgets/blake2s.rs
+++ b/bellman/src/gadgets/blake2s.rs
@@ -382,7 +382,7 @@ pub fn blake2s<E: Engine, CS: ConstraintSystem<E>>(
         blocks.push(this_block);
     }
 
-    if blocks.len() == 0 {
+    if blocks.is_empty() {
         blocks.push((0..16).map(|_| UInt32::constant(0)).collect());
     }
 
@@ -433,7 +433,7 @@ mod test {
         let expected = hex!("c59f682376d137f3f255e671e207d1f2374ebe504e9314208a52d9f88d69e8c8");
 
         let mut out = out.into_iter();
-        for b in expected.into_iter() {
+        for b in expected.iter() {
             for i in 0..8 {
                 let c = out.next().unwrap().get_value().unwrap();
 
diff --git a/bellman/src/gadgets/boolean.rs b/bellman/src/gadgets/boolean.rs
index 414b290..b26bb19 100644
--- a/bellman/src/gadgets/boolean.rs
+++ b/bellman/src/gadgets/boolean.rs
@@ -60,7 +60,7 @@ impl AllocatedBit {
 
         Ok(AllocatedBit {
             variable: var,
-            value: value,
+            value,
         })
     }
 
@@ -93,7 +93,7 @@ impl AllocatedBit {
 
         Ok(AllocatedBit {
             variable: var,
-            value: value,
+            value,
         })
     }
 
@@ -302,7 +302,7 @@ pub fn field_into_boolean_vec_le<E: Engine, CS: ConstraintSystem<E>, F: PrimeFie
 ) -> Result<Vec<Boolean>, SynthesisError> {
     let v = field_into_allocated_bits_le::<E, CS, F>(cs, value)?;
 
-    Ok(v.into_iter().map(|e| Boolean::from(e)).collect())
+    Ok(v.into_iter().map(Boolean::from).collect())
 }
 
 pub fn field_into_allocated_bits_le<E: Engine, CS: ConstraintSystem<E>, F: PrimeField>(
@@ -412,24 +412,24 @@ impl Boolean {
     }
 
     pub fn get_value(&self) -> Option<bool> {
-        match self {
-            &Boolean::Constant(c) => Some(c),
-            &Boolean::Is(ref v) => v.get_value(),
-            &Boolean::Not(ref v) => v.get_value().map(|b| !b),
+        match *self {
+            Boolean::Constant(c) => Some(c),
+            Boolean::Is(ref v) => v.get_value(),
+            Boolean::Not(ref v) => v.get_value().map(|b| !b),
         }
     }
 
     pub fn lc<E: Engine>(&self, one: Variable, coeff: E::Fr) -> LinearCombination<E> {
-        match self {
-            &Boolean::Constant(c) => {
+        match *self {
+            Boolean::Constant(c) => {
                 if c {
                     LinearCombination::<E>::zero() + (coeff, one)
                 } else {
                     LinearCombination::<E>::zero()
                 }
             }
-            &Boolean::Is(ref v) => LinearCombination::<E>::zero() + (coeff, v.get_variable()),
-            &Boolean::Not(ref v) => {
+            Boolean::Is(ref v) => LinearCombination::<E>::zero() + (coeff, v.get_variable()),
+            Boolean::Not(ref v) => {
                 LinearCombination::<E>::zero() + (coeff, one) - (coeff, v.get_variable())
             }
         }
@@ -442,10 +442,10 @@ impl Boolean {
 
     /// Return a negated interpretation of this boolean.
     pub fn not(&self) -> Self {
-        match self {
-            &Boolean::Constant(c) => Boolean::Constant(!c),
-            &Boolean::Is(ref v) => Boolean::Not(v.clone()),
-            &Boolean::Not(ref v) => Boolean::Is(v.clone()),
+        match *self {
+            Boolean::Constant(c) => Boolean::Constant(!c),
+            Boolean::Is(ref v) => Boolean::Not(v.clone()),
+            Boolean::Not(ref v) => Boolean::Is(v.clone()),
         }
     }
 
diff --git a/bellman/src/gadgets/multieq.rs b/bellman/src/gadgets/multieq.rs
index 510802d..095017a 100644
--- a/bellman/src/gadgets/multieq.rs
+++ b/bellman/src/gadgets/multieq.rs
@@ -14,7 +14,7 @@ pub struct MultiEq<E: Engine, CS: ConstraintSystem<E>> {
 impl<E: Engine, CS: ConstraintSystem<E>> MultiEq<E, CS> {
     pub fn new(cs: CS) -> Self {
         MultiEq {
-            cs: cs,
+            cs,
             ops: 0,
             bits_used: 0,
             lhs: LinearCombination::zero(),
diff --git a/bellman/src/gadgets/num.rs b/bellman/src/gadgets/num.rs
index 84843c1..81f4fb3 100644
--- a/bellman/src/gadgets/num.rs
+++ b/bellman/src/gadgets/num.rs
@@ -78,7 +78,7 @@ impl<E: Engine> AllocatedNum<E> {
             E: Engine,
             CS: ConstraintSystem<E>,
         {
-            assert!(v.len() > 0);
+            assert!(!v.is_empty());
 
             // Let's keep this simple for now and just AND them all
             // manually
@@ -132,7 +132,7 @@ impl<E: Engine> AllocatedNum<E> {
                 current_run.push(a_bit.clone());
                 result.push(a_bit);
             } else {
-                if current_run.len() > 0 {
+                if !current_run.is_empty() {
                     // This is the start of a run of zeros, but we need
                     // to k-ary AND against `last_run` first.
 
@@ -183,7 +183,7 @@ impl<E: Engine> AllocatedNum<E> {
         cs.enforce(|| "unpacking constraint", |lc| lc, |lc| lc, |_| lc);
 
         // Convert into booleans, and reverse for little-endian bit order
-        Ok(result.into_iter().map(|b| Boolean::from(b)).rev().collect())
+        Ok(result.into_iter().map(Boolean::from).rev().collect())
     }
 
     /// Convert the allocated number into its little-endian representation.
@@ -208,7 +208,7 @@ impl<E: Engine> AllocatedNum<E> {
 
         cs.enforce(|| "unpacking constraint", |lc| lc, |lc| lc, |_| lc);
 
-        Ok(bits.into_iter().map(|b| Boolean::from(b)).collect())
+        Ok(bits.into_iter().map(Boolean::from).collect())
     }
 
     pub fn mul<CS>(&self, mut cs: CS, other: &Self) -> Result<Self, SynthesisError>
@@ -238,7 +238,7 @@ impl<E: Engine> AllocatedNum<E> {
         );
 
         Ok(AllocatedNum {
-            value: value,
+            value,
             variable: var,
         })
     }
@@ -270,7 +270,7 @@ impl<E: Engine> AllocatedNum<E> {
         );
 
         Ok(AllocatedNum {
-            value: value,
+            value,
             variable: var,
         })
     }
diff --git a/bellman/src/gadgets/sha256.rs b/bellman/src/gadgets/sha256.rs
index cb057f8..e346a71 100644
--- a/bellman/src/gadgets/sha256.rs
+++ b/bellman/src/gadgets/sha256.rs
@@ -4,6 +4,7 @@ use super::uint32::UInt32;
 use crate::{ConstraintSystem, SynthesisError};
 use pairing::Engine;
 
+#[allow(clippy::unreadable_literal)]
 const ROUND_CONSTANTS: [u32; 64] = [
     0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
     0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
@@ -15,6 +16,7 @@ const ROUND_CONSTANTS: [u32; 64] = [
     0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2,
 ];
 
+#[allow(clippy::unreadable_literal)]
 const IV: [u32; 8] = [
     0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a, 0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19,
 ];
@@ -130,7 +132,7 @@ where
             Ok(match self {
                 Maybe::Concrete(ref v) => return Ok(v.clone()),
                 Maybe::Deferred(mut v) => {
-                    v.extend(others.into_iter().cloned());
+                    v.extend(others.iter().cloned());
                     UInt32::addmany(cs, &v)?
                 }
             })
@@ -286,7 +288,7 @@ mod test {
         let expected = hex!("e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855");
 
         let mut out = out_bits.into_iter();
-        for b in expected.into_iter() {
+        for b in expected.iter() {
             for i in (0..8).rev() {
                 let c = out.next().unwrap().get_value().unwrap();
 
diff --git a/bellman/src/gadgets/test/mod.rs b/bellman/src/gadgets/test/mod.rs
index 58ba040..eed676e 100644
--- a/bellman/src/gadgets/test/mod.rs
+++ b/bellman/src/gadgets/test/mod.rs
@@ -66,7 +66,7 @@ fn proc_lc<E: Engine>(terms: &[(Variable, E::Fr)]) -> BTreeMap<OrderedVariable,
     let mut map = BTreeMap::new();
     for &(var, coeff) in terms {
         map.entry(OrderedVariable(var))
-            .or_insert(E::Fr::zero())
+            .or_insert_with(E::Fr::zero)
             .add_assign(&coeff);
     }
 
@@ -157,7 +157,7 @@ impl<E: Engine> TestConstraintSystem<E> {
         };
 
         let powers_of_two = (0..E::Fr::NUM_BITS)
-            .map(|i| E::Fr::from_str("2").unwrap().pow(&[i as u64]))
+            .map(|i| E::Fr::from_str("2").unwrap().pow(&[u64::from(i)]))
             .collect::<Vec<_>>();
 
         let pp = |s: &mut String, lc: &LinearCombination<E>| {
@@ -286,7 +286,7 @@ impl<E: Engine> TestConstraintSystem<E> {
             }
         }
 
-        return true;
+        true
     }
 
     pub fn num_inputs(&self) -> usize {
diff --git a/bellman/src/gadgets/uint32.rs b/bellman/src/gadgets/uint32.rs
index ef3f44a..3467400 100644
--- a/bellman/src/gadgets/uint32.rs
+++ b/bellman/src/gadgets/uint32.rs
@@ -33,7 +33,7 @@ impl UInt32 {
         }
 
         UInt32 {
-            bits: bits,
+            bits,
             value: Some(value),
         }
     }
@@ -69,10 +69,7 @@ impl UInt32 {
             })
             .collect::<Result<Vec<_>, SynthesisError>>()?;
 
-        Ok(UInt32 {
-            bits: bits,
-            value: value,
-        })
+        Ok(UInt32 { bits, value })
     }
 
     pub fn into_bits_be(&self) -> Vec<Boolean> {
@@ -98,7 +95,7 @@ impl UInt32 {
         }
 
         UInt32 {
-            value: value,
+            value,
             bits: bits.iter().rev().cloned().collect(),
         }
     }
@@ -119,20 +116,20 @@ impl UInt32 {
         for b in new_bits.iter().rev() {
             value.as_mut().map(|v| *v <<= 1);
 
-            match b {
-                &Boolean::Constant(b) => {
+            match *b {
+                Boolean::Constant(b) => {
                     if b {
                         value.as_mut().map(|v| *v |= 1);
                     }
                 }
-                &Boolean::Is(ref b) => match b.get_value() {
+                Boolean::Is(ref b) => match b.get_value() {
                     Some(true) => {
                         value.as_mut().map(|v| *v |= 1);
                     }
                     Some(false) => {}
                     None => value = None,
                 },
-                &Boolean::Not(ref b) => match b.get_value() {
+                Boolean::Not(ref b) => match b.get_value() {
                     Some(false) => {
                         value.as_mut().map(|v| *v |= 1);
                     }
@@ -143,7 +140,7 @@ impl UInt32 {
         }
 
         UInt32 {
-            value: value,
+            value,
             bits: new_bits,
         }
     }
@@ -215,7 +212,7 @@ impl UInt32 {
             .collect::<Result<_, _>>()?;
 
         Ok(UInt32 {
-            bits: bits,
+            bits,
             value: new_value,
         })
     }
@@ -274,7 +271,7 @@ impl UInt32 {
             .collect::<Result<_, _>>()?;
 
         Ok(UInt32 {
-            bits: bits,
+            bits,
             value: new_value,
         })
     }
@@ -294,7 +291,7 @@ impl UInt32 {
 
         // Compute the maximum value of the sum so we allocate enough bits for
         // the result
-        let mut max_value = (operands.len() as u64) * (u32::max_value() as u64);
+        let mut max_value = (operands.len() as u64) * (u64::from(u32::max_value()));
 
         // Keep track of the resulting value
         let mut result_value = Some(0u64);
@@ -310,7 +307,7 @@ impl UInt32 {
             // Accumulate the value
             match op.value {
                 Some(val) => {
-                    result_value.as_mut().map(|v| *v += val as u64);
+                    result_value.as_mut().map(|v| *v += u64::from(val));
                 }
                 None => {
                     // If any of our operands have unknown value, we won't
@@ -408,8 +405,8 @@ mod test {
             let b = UInt32::from_bits_be(&v);
 
             for (i, bit) in b.bits.iter().enumerate() {
-                match bit {
-                    &Boolean::Constant(bit) => {
+                match *bit {
+                    Boolean::Constant(bit) => {
                         assert!(bit == ((b.value.unwrap() >> i) & 1 == 1));
                     }
                     _ => unreachable!(),
@@ -443,8 +440,8 @@ mod test {
             let b = UInt32::from_bits(&v);
 
             for (i, bit) in b.bits.iter().enumerate() {
-                match bit {
-                    &Boolean::Constant(bit) => {
+                match *bit {
+                    Boolean::Constant(bit) => {
                         assert!(bit == ((b.value.unwrap() >> i) & 1 == 1));
                     }
                     _ => unreachable!(),
@@ -491,14 +488,14 @@ mod test {
             assert!(r.value == Some(expected));
 
             for b in r.bits.iter() {
-                match b {
-                    &Boolean::Is(ref b) => {
+                match *b {
+                    Boolean::Is(ref b) => {
                         assert!(b.get_value().unwrap() == (expected & 1 == 1));
                     }
-                    &Boolean::Not(ref b) => {
+                    Boolean::Not(ref b) => {
                         assert!(!b.get_value().unwrap() == (expected & 1 == 1));
                     }
-                    &Boolean::Constant(b) => {
+                    Boolean::Constant(b) => {
                         assert!(b == (expected & 1 == 1));
                     }
                 }
@@ -538,10 +535,10 @@ mod test {
             assert!(r.value == Some(expected));
 
             for b in r.bits.iter() {
-                match b {
-                    &Boolean::Is(_) => panic!(),
-                    &Boolean::Not(_) => panic!(),
-                    &Boolean::Constant(b) => {
+                match *b {
+                    Boolean::Is(_) => panic!(),
+                    Boolean::Not(_) => panic!(),
+                    Boolean::Constant(b) => {
                         assert!(b == (expected & 1 == 1));
                     }
                 }
@@ -576,8 +573,7 @@ mod test {
             let r = a_bit.xor(cs.namespace(|| "xor"), &b_bit).unwrap();
             let r = {
                 let mut cs = MultiEq::new(&mut cs);
-                let r = UInt32::addmany(cs.namespace(|| "addition"), &[r, c_bit, d_bit]).unwrap();
-                r
+                UInt32::addmany(cs.namespace(|| "addition"), &[r, c_bit, d_bit]).unwrap()
             };
 
             assert!(cs.is_satisfied());
@@ -585,14 +581,14 @@ mod test {
             assert!(r.value == Some(expected));
 
             for b in r.bits.iter() {
-                match b {
-                    &Boolean::Is(ref b) => {
+                match *b {
+                    Boolean::Is(ref b) => {
                         assert!(b.get_value().unwrap() == (expected & 1 == 1));
                     }
-                    &Boolean::Not(ref b) => {
+                    Boolean::Not(ref b) => {
                         assert!(!b.get_value().unwrap() == (expected & 1 == 1));
                     }
-                    &Boolean::Constant(_) => unreachable!(),
+                    Boolean::Constant(_) => unreachable!(),
                 }
 
                 expected >>= 1;
@@ -628,8 +624,8 @@ mod test {
 
             let mut tmp = num;
             for b in &b.bits {
-                match b {
-                    &Boolean::Constant(b) => {
+                match *b {
+                    Boolean::Constant(b) => {
                         assert_eq!(b, tmp & 1 == 1);
                     }
                     _ => unreachable!(),
diff --git a/bellman/src/groth16/generator.rs b/bellman/src/groth16/generator.rs
index 2ece8b7..7ca6c9a 100644
--- a/bellman/src/groth16/generator.rs
+++ b/bellman/src/groth16/generator.rs
@@ -451,7 +451,7 @@ where
     };
 
     Ok(Parameters {
-        vk: vk,
+        vk,
         h: Arc::new(h.into_iter().map(|e| e.into_affine()).collect()),
         l: Arc::new(l.into_iter().map(|e| e.into_affine()).collect()),
 
diff --git a/bellman/src/groth16/mod.rs b/bellman/src/groth16/mod.rs
index 9fa3bc8..44c6f22 100644
--- a/bellman/src/groth16/mod.rs
+++ b/bellman/src/groth16/mod.rs
@@ -90,7 +90,7 @@ impl<E: Engine> Proof<E> {
                 }
             })?;
 
-        Ok(Proof { a: a, b: b, c: c })
+        Ok(Proof { a, b, c })
     }
 }
 
@@ -208,13 +208,13 @@ impl<E: Engine> VerifyingKey<E> {
         }
 
         Ok(VerifyingKey {
-            alpha_g1: alpha_g1,
-            beta_g1: beta_g1,
-            beta_g2: beta_g2,
-            gamma_g2: gamma_g2,
-            delta_g1: delta_g1,
-            delta_g2: delta_g2,
-            ic: ic,
+            alpha_g1,
+            beta_g1,
+            beta_g2,
+            gamma_g2,
+            delta_g1,
+            delta_g2,
+            ic,
         })
     }
 }
@@ -376,7 +376,7 @@ impl<E: Engine> Parameters<E> {
         }
 
         Ok(Parameters {
-            vk: vk,
+            vk,
             h: Arc::new(h),
             l: Arc::new(l),
             a: Arc::new(a),
diff --git a/bellman/src/groth16/verifier.rs b/bellman/src/groth16/verifier.rs
index 065a3b0..5bc0581 100644
--- a/bellman/src/groth16/verifier.rs
+++ b/bellman/src/groth16/verifier.rs
@@ -49,7 +49,7 @@ pub fn verify_proof<'a, E: Engine>(
             (&acc.into_affine().prepare(), &pvk.neg_gamma_g2),
             (&proof.c.prepare(), &pvk.neg_delta_g2),
         ]
-        .into_iter(),
+        .iter(),
     ))
     .unwrap()
         == pvk.alpha_g1_beta_g2)
diff --git a/bellman/src/lib.rs b/bellman/src/lib.rs
index a75c85f..1445107 100644
--- a/bellman/src/lib.rs
+++ b/bellman/src/lib.rs
@@ -91,6 +91,7 @@ impl<E: ScalarEngine> Add<(E::Fr, Variable)> for LinearCombination<E> {
 impl<E: ScalarEngine> Sub<(E::Fr, Variable)> for LinearCombination<E> {
     type Output = LinearCombination<E>;
 
+    #[allow(clippy::suspicious_arithmetic_impl)]
     fn sub(self, (mut coeff, var): (E::Fr, Variable)) -> LinearCombination<E> {
         coeff.negate();
 
@@ -213,7 +214,7 @@ impl Error for SynthesisError {
 
 impl fmt::Display for SynthesisError {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
-        if let &SynthesisError::IoError(ref e) = self {
+        if let SynthesisError::IoError(ref e) = *self {
             write!(f, "I/O error: ")?;
             e.fmt(f)
         } else {
@@ -278,7 +279,7 @@ pub trait ConstraintSystem<E: ScalarEngine>: Sized {
     fn get_root(&mut self) -> &mut Self::Root;
 
     /// Begin a namespace for this constraint system.
-    fn namespace<'a, NR, N>(&'a mut self, name_fn: N) -> Namespace<'a, E, Self::Root>
+    fn namespace<NR, N>(&mut self, name_fn: N) -> Namespace<'_, E, Self::Root>
     where
         NR: Into<String>,
         N: FnOnce() -> NR,
diff --git a/bellman/src/multicore.rs b/bellman/src/multicore.rs
index e8b2dae..7ebc89a 100644
--- a/bellman/src/multicore.rs
+++ b/bellman/src/multicore.rs
@@ -23,7 +23,7 @@ mod implementation {
         // CPUs configured.
         pub(crate) fn new_with_cpus(cpus: usize) -> Worker {
             Worker {
-                cpus: cpus,
+                cpus,
                 pool: CpuPool::new(cpus),
             }
         }

From 3a8efd9e677ebfe6de7669b865a780ec89caabd6 Mon Sep 17 00:00:00 2001
From: Jack Grigg <jack@z.cash>
Date: Fri, 2 Aug 2019 11:25:00 +0100
Subject: [PATCH 3/8] Address various clippy warnings/errors in
 zcash_primitives

---
 zcash_primitives/src/block.rs                 |  2 +-
 zcash_primitives/src/block/equihash.rs        | 22 ++++------
 zcash_primitives/src/constants.rs             | 18 ++++----
 zcash_primitives/src/jubjub/edwards.rs        | 12 +++---
 zcash_primitives/src/jubjub/fs.rs             |  4 +-
 zcash_primitives/src/jubjub/mod.rs            |  4 +-
 zcash_primitives/src/jubjub/montgomery.rs     | 15 ++++---
 zcash_primitives/src/keys.rs                  |  6 +--
 zcash_primitives/src/merkle_tree.rs           |  6 ++-
 zcash_primitives/src/note_encryption.rs       |  6 +--
 zcash_primitives/src/primitives.rs            |  9 ++--
 zcash_primitives/src/sapling.rs               |  4 +-
 zcash_primitives/src/serialize.rs             |  2 +-
 zcash_primitives/src/transaction/builder.rs   |  6 +--
 .../src/transaction/components.rs             | 41 ++++++++-----------
 zcash_primitives/src/transaction/mod.rs       | 23 ++++++-----
 zcash_primitives/src/transaction/sighash.rs   | 14 +++----
 zcash_primitives/src/zip32.rs                 | 10 ++---
 18 files changed, 97 insertions(+), 107 deletions(-)

diff --git a/zcash_primitives/src/block.rs b/zcash_primitives/src/block.rs
index 63e6a05..28a7441 100644
--- a/zcash_primitives/src/block.rs
+++ b/zcash_primitives/src/block.rs
@@ -13,7 +13,7 @@ pub struct BlockHash(pub [u8; 32]);
 
 impl fmt::Display for BlockHash {
     fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
-        let mut data = self.0.clone();
+        let mut data = self.0;
         data.reverse();
         formatter.write_str(&hex::encode(data))
     }
diff --git a/zcash_primitives/src/block/equihash.rs b/zcash_primitives/src/block/equihash.rs
index d251bc1..9710dc9 100644
--- a/zcash_primitives/src/block/equihash.rs
+++ b/zcash_primitives/src/block/equihash.rs
@@ -60,10 +60,7 @@ impl Node {
             indices.extend(a.indices.iter());
             indices
         };
-        Node {
-            hash: hash,
-            indices: indices,
-        }
+        Node { hash, indices }
     }
 
     fn from_children_ref(a: &Node, b: &Node, trim: usize) -> Self {
@@ -82,10 +79,7 @@ impl Node {
             indices.extend(b.indices.iter());
             indices.extend(a.indices.iter());
         }
-        Node {
-            hash: hash,
-            indices: indices,
-        }
+        Node { hash, indices }
     }
 
     fn indices_before(&self, other: &Node) -> bool {
@@ -141,7 +135,7 @@ fn expand_array(vin: &[u8], bit_len: usize, byte_pad: usize) -> Vec<u8> {
 
     let mut j = 0;
     for b in vin {
-        acc_value = (acc_value << 8) | *b as u32;
+        acc_value = (acc_value << 8) | u32::from(*b);
         acc_bits += 8;
 
         // When we have bit_len or more bits in the accumulator, write the next
@@ -197,7 +191,7 @@ fn distinct_indices(a: &Node, b: &Node) -> bool {
             }
         }
     }
-    return true;
+    true
 }
 
 fn validate_subtrees(p: &Params, a: &Node, b: &Node) -> bool {
@@ -222,7 +216,7 @@ pub fn is_valid_solution_iterative(
     nonce: &[u8],
     indices: &[u32],
 ) -> bool {
-    let p = Params { n: n, k: k };
+    let p = Params { n, k };
 
     let mut state = initialise_state(p.n, p.k, p.hash_output());
     state.update(input);
@@ -249,7 +243,7 @@ pub fn is_valid_solution_iterative(
     }
 
     assert!(rows.len() == 1);
-    return rows[0].is_zero(hash_len);
+    rows[0].is_zero(hash_len)
 }
 
 fn tree_validator(p: &Params, state: &Blake2bState, indices: &[u32]) -> Option<Node> {
@@ -281,7 +275,7 @@ pub fn is_valid_solution_recursive(
     nonce: &[u8],
     indices: &[u32],
 ) -> bool {
-    let p = Params { n: n, k: k };
+    let p = Params { n, k };
 
     let mut state = initialise_state(p.n, p.k, p.hash_output());
     state.update(input);
@@ -297,7 +291,7 @@ pub fn is_valid_solution_recursive(
 }
 
 pub fn is_valid_solution(n: u32, k: u32, input: &[u8], nonce: &[u8], soln: &[u8]) -> bool {
-    let p = Params { n: n, k: k };
+    let p = Params { n, k };
     let indices = indices_from_minimal(soln, p.collision_bit_length());
 
     // Recursive validation is faster
diff --git a/zcash_primitives/src/constants.rs b/zcash_primitives/src/constants.rs
index c21184d..39d55f3 100644
--- a/zcash_primitives/src/constants.rs
+++ b/zcash_primitives/src/constants.rs
@@ -2,31 +2,31 @@
 /// This is chosen to be some random string that we couldn't have anticipated when we designed
 /// the algorithm, for rigidity purposes.
 /// We deliberately use an ASCII hex string of 32 bytes here.
-pub const GH_FIRST_BLOCK: &'static [u8; 64] =
+pub const GH_FIRST_BLOCK: &[u8; 64] =
     b"096b36a5804bfacef1691e173c366a47ff5ba84a44f26ddd7e8d9f79d5b42df0";
 
 // BLAKE2s invocation personalizations
 /// BLAKE2s Personalization for CRH^ivk = BLAKE2s(ak | nk)
-pub const CRH_IVK_PERSONALIZATION: &'static [u8; 8] = b"Zcashivk";
+pub const CRH_IVK_PERSONALIZATION: &[u8; 8] = b"Zcashivk";
 
 /// BLAKE2s Personalization for PRF^nf = BLAKE2s(nk | rho)
-pub const PRF_NF_PERSONALIZATION: &'static [u8; 8] = b"Zcash_nf";
+pub const PRF_NF_PERSONALIZATION: &[u8; 8] = b"Zcash_nf";
 
 // Group hash personalizations
 /// BLAKE2s Personalization for Pedersen hash generators.
-pub const PEDERSEN_HASH_GENERATORS_PERSONALIZATION: &'static [u8; 8] = b"Zcash_PH";
+pub const PEDERSEN_HASH_GENERATORS_PERSONALIZATION: &[u8; 8] = b"Zcash_PH";
 
 /// BLAKE2s Personalization for the group hash for key diversification
-pub const KEY_DIVERSIFICATION_PERSONALIZATION: &'static [u8; 8] = b"Zcash_gd";
+pub const KEY_DIVERSIFICATION_PERSONALIZATION: &[u8; 8] = b"Zcash_gd";
 
 /// BLAKE2s Personalization for the spending key base point
-pub const SPENDING_KEY_GENERATOR_PERSONALIZATION: &'static [u8; 8] = b"Zcash_G_";
+pub const SPENDING_KEY_GENERATOR_PERSONALIZATION: &[u8; 8] = b"Zcash_G_";
 
 /// BLAKE2s Personalization for the proof generation key base point
-pub const PROOF_GENERATION_KEY_BASE_GENERATOR_PERSONALIZATION: &'static [u8; 8] = b"Zcash_H_";
+pub const PROOF_GENERATION_KEY_BASE_GENERATOR_PERSONALIZATION: &[u8; 8] = b"Zcash_H_";
 
 /// BLAKE2s Personalization for the value commitment generator for the value
-pub const VALUE_COMMITMENT_GENERATOR_PERSONALIZATION: &'static [u8; 8] = b"Zcash_cv";
+pub const VALUE_COMMITMENT_GENERATOR_PERSONALIZATION: &[u8; 8] = b"Zcash_cv";
 
 /// BLAKE2s Personalization for the nullifier position generator (for computing rho)
-pub const NULLIFIER_POSITION_IN_TREE_GENERATOR_PERSONALIZATION: &'static [u8; 8] = b"Zcash_J_";
+pub const NULLIFIER_POSITION_IN_TREE_GENERATOR_PERSONALIZATION: &[u8; 8] = b"Zcash_J_";
diff --git a/zcash_primitives/src/jubjub/edwards.rs b/zcash_primitives/src/jubjub/edwards.rs
index b3cdd64..233bfb7 100644
--- a/zcash_primitives/src/jubjub/edwards.rs
+++ b/zcash_primitives/src/jubjub/edwards.rs
@@ -132,9 +132,9 @@ impl<E: JubjubEngine> Point<E, Unknown> {
                         t.mul_assign(&y);
 
                         Some(Point {
-                            x: x,
-                            y: y,
-                            t: t,
+                            x,
+                            y,
+                            t,
                             z: E::Fr::one(),
                             _marker: PhantomData,
                         })
@@ -277,8 +277,8 @@ impl<E: JubjubEngine, Subgroup> Point<E, Subgroup> {
                     Point {
                         x: u,
                         y: v,
-                        t: t,
-                        z: z,
+                        t,
+                        z,
                         _marker: PhantomData,
                     }
                 }
@@ -412,7 +412,7 @@ impl<E: JubjubEngine, Subgroup> Point<E, Subgroup> {
         b.mul_assign(&other.y);
 
         // C = d * t1 * t2
-        let mut c = params.edwards_d().clone();
+        let mut c = *params.edwards_d();
         c.mul_assign(&self.t);
         c.mul_assign(&other.t);
 
diff --git a/zcash_primitives/src/jubjub/fs.rs b/zcash_primitives/src/jubjub/fs.rs
index 0d1578e..7cf4d79 100644
--- a/zcash_primitives/src/jubjub/fs.rs
+++ b/zcash_primitives/src/jubjub/fs.rs
@@ -321,8 +321,8 @@ impl Field for Fs {
         loop {
             let mut tmp = {
                 let mut repr = [0u64; 4];
-                for i in 0..4 {
-                    repr[i] = rng.next_u64();
+                for limb in &mut repr {
+                    *limb = rng.next_u64();
                 }
                 Fs(FsRepr(repr))
             };
diff --git a/zcash_primitives/src/jubjub/mod.rs b/zcash_primitives/src/jubjub/mod.rs
index 8d9e227..624592e 100644
--- a/zcash_primitives/src/jubjub/mod.rs
+++ b/zcash_primitives/src/jubjub/mod.rs
@@ -199,9 +199,9 @@ impl JubjubBls12 {
             )
             .unwrap(),
             // A = 40962
-            montgomery_a: montgomery_a,
+            montgomery_a,
             // 2A = 2.A
-            montgomery_2a: montgomery_2a,
+            montgomery_2a,
             // scaling factor = sqrt(4 / (a - d))
             scale: Fr::from_str(
                 "17814886934372412843466061268024708274627479829237077604635722030778476050649",
diff --git a/zcash_primitives/src/jubjub/montgomery.rs b/zcash_primitives/src/jubjub/montgomery.rs
index e0bc4bf..0ebedd2 100644
--- a/zcash_primitives/src/jubjub/montgomery.rs
+++ b/zcash_primitives/src/jubjub/montgomery.rs
@@ -64,12 +64,12 @@ impl<E: JubjubEngine> Point<E, Unknown> {
                     y.negate();
                 }
 
-                return Some(Point {
-                    x: x,
-                    y: y,
+                Some(Point {
+                    x,
+                    y,
                     infinity: false,
                     _marker: PhantomData,
-                });
+                })
             }
             None => None,
         }
@@ -88,9 +88,8 @@ impl<E: JubjubEngine> Point<E, Unknown> {
             let x = E::Fr::random(rng);
             let sign = rng.next_u32() % 2 != 0;
 
-            match Self::get_for_x(x, sign, params) {
-                Some(p) => return p,
-                None => {}
+            if let Some(p) = Self::get_for_x(x, sign, params) {
+                return p;
             }
         }
     }
@@ -214,7 +213,7 @@ impl<E: JubjubEngine, Subgroup> Point<E, Subgroup> {
 
         let mut delta = E::Fr::one();
         {
-            let mut tmp = params.montgomery_a().clone();
+            let mut tmp = *params.montgomery_a();
             tmp.mul_assign(&self.x);
             tmp.double();
             delta.add_assign(&tmp);
diff --git a/zcash_primitives/src/keys.rs b/zcash_primitives/src/keys.rs
index ad86059..8c8a4b1 100644
--- a/zcash_primitives/src/keys.rs
+++ b/zcash_primitives/src/keys.rs
@@ -10,11 +10,11 @@ use blake2b_simd::{Hash as Blake2bHash, Params as Blake2bParams};
 use ff::{PrimeField, PrimeFieldRepr};
 use std::io::{self, Read, Write};
 
-pub const PRF_EXPAND_PERSONALIZATION: &'static [u8; 16] = b"Zcash_ExpandSeed";
+pub const PRF_EXPAND_PERSONALIZATION: &[u8; 16] = b"Zcash_ExpandSeed";
 
 /// PRF^expand(sk, t) := BLAKE2b-512("Zcash_ExpandSeed", sk || t)
 pub fn prf_expand(sk: &[u8], t: &[u8]) -> Blake2bHash {
-    prf_expand_vec(sk, &vec![t])
+    prf_expand_vec(sk, &[t])
 }
 
 pub fn prf_expand_vec(sk: &[u8], ts: &[&[u8]]) -> Blake2bHash {
@@ -111,7 +111,7 @@ impl<E: JubjubEngine> Clone for FullViewingKey<E> {
                 ak: self.vk.ak.clone(),
                 nk: self.vk.nk.clone(),
             },
-            ovk: self.ovk.clone(),
+            ovk: self.ovk,
         }
     }
 }
diff --git a/zcash_primitives/src/merkle_tree.rs b/zcash_primitives/src/merkle_tree.rs
index 288ad21..2721ab6 100644
--- a/zcash_primitives/src/merkle_tree.rs
+++ b/zcash_primitives/src/merkle_tree.rs
@@ -486,8 +486,10 @@ impl<Node: Hashable> CommitmentTreeWitness<Node> {
         // Given the position, let's finish constructing the authentication
         // path
         let mut tmp = position;
-        for i in 0..depth {
-            auth_path[i].as_mut().map(|p| p.1 = (tmp & 1) == 1);
+        for entry in auth_path.iter_mut() {
+            if let Some(p) = entry {
+                p.1 = (tmp & 1) == 1;
+            }
 
             tmp >>= 1;
         }
diff --git a/zcash_primitives/src/note_encryption.rs b/zcash_primitives/src/note_encryption.rs
index 5412945..0d0e83a 100644
--- a/zcash_primitives/src/note_encryption.rs
+++ b/zcash_primitives/src/note_encryption.rs
@@ -19,8 +19,8 @@ use std::str;
 
 use crate::{keys::OutgoingViewingKey, JUBJUB};
 
-pub const KDF_SAPLING_PERSONALIZATION: &'static [u8; 16] = b"Zcash_SaplingKDF";
-pub const PRF_OCK_PERSONALIZATION: &'static [u8; 16] = b"Zcash_Derive_ock";
+pub const KDF_SAPLING_PERSONALIZATION: &[u8; 16] = b"Zcash_SaplingKDF";
+pub const PRF_OCK_PERSONALIZATION: &[u8; 16] = b"Zcash_Derive_ock";
 
 const COMPACT_NOTE_SIZE: usize = (
     1  + // version
@@ -85,7 +85,7 @@ impl Default for Memo {
 
 impl PartialEq for Memo {
     fn eq(&self, rhs: &Memo) -> bool {
-        &self.0[..] == &rhs.0[..]
+        self.0[..] == rhs.0[..]
     }
 }
 
diff --git a/zcash_primitives/src/primitives.rs b/zcash_primitives/src/primitives.rs
index 10a6d6b..38a056a 100644
--- a/zcash_primitives/src/primitives.rs
+++ b/zcash_primitives/src/primitives.rs
@@ -97,10 +97,7 @@ impl<E: JubjubEngine> ViewingKey<E> {
         diversifier.g_d(params).map(|g_d| {
             let pk_d = g_d.mul(self.ivk(), params);
 
-            PaymentAddress {
-                pk_d: pk_d,
-                diversifier: diversifier,
-            }
+            PaymentAddress { pk_d, diversifier }
         })
     }
 }
@@ -145,9 +142,9 @@ impl<E: JubjubEngine> PaymentAddress<E> {
         params: &E::Params,
     ) -> Option<Note<E>> {
         self.g_d(params).map(|g_d| Note {
-            value: value,
+            value,
             r: randomness,
-            g_d: g_d,
+            g_d,
             pk_d: self.pk_d.clone(),
         })
     }
diff --git a/zcash_primitives/src/sapling.rs b/zcash_primitives/src/sapling.rs
index d84eec2..8b8ef88 100644
--- a/zcash_primitives/src/sapling.rs
+++ b/zcash_primitives/src/sapling.rs
@@ -37,9 +37,9 @@ pub fn merkle_hash(depth: usize, lhs: &FrRepr, rhs: &FrRepr) -> FrRepr {
     pedersen_hash::<Bls12, _>(
         Personalization::MerkleTree(depth),
         lhs.iter()
-            .map(|&x| x)
+            .copied()
             .take(Fr::NUM_BITS as usize)
-            .chain(rhs.iter().map(|&x| x).take(Fr::NUM_BITS as usize)),
+            .chain(rhs.iter().copied().take(Fr::NUM_BITS as usize)),
         &JUBJUB,
     )
     .into_xy()
diff --git a/zcash_primitives/src/serialize.rs b/zcash_primitives/src/serialize.rs
index 41778dc..4e0fb93 100644
--- a/zcash_primitives/src/serialize.rs
+++ b/zcash_primitives/src/serialize.rs
@@ -70,7 +70,7 @@ impl Vector {
         F: Fn(&mut R) -> io::Result<E>,
     {
         let count = CompactSize::read(&mut reader)?;
-        (0..count).into_iter().map(|_| func(&mut reader)).collect()
+        (0..count).map(|_| func(&mut reader)).collect()
     }
 
     pub fn write<W: Write, E, F>(mut writer: W, vec: &[E], func: F) -> io::Result<()>
diff --git a/zcash_primitives/src/transaction/builder.rs b/zcash_primitives/src/transaction/builder.rs
index a5df4c8..1f30f99 100644
--- a/zcash_primitives/src/transaction/builder.rs
+++ b/zcash_primitives/src/transaction/builder.rs
@@ -153,7 +153,7 @@ impl TransactionMetadata {
     /// they added (via the first call to [`Builder::add_sapling_spend`]) is the first
     /// [`SpendDescription`] in the transaction.
     pub fn spend_index(&self, n: usize) -> Option<usize> {
-        self.spend_indices.get(n).map(|i| *i)
+        self.spend_indices.get(n).copied()
     }
 
     /// Returns the index within the transaction of the [`OutputDescription`] corresponding
@@ -164,7 +164,7 @@ impl TransactionMetadata {
     /// they added (via the first call to [`Builder::add_sapling_output`]) is the first
     /// [`OutputDescription`] in the transaction.
     pub fn output_index(&self, n: usize) -> Option<usize> {
-        self.output_indices.get(n).map(|i| *i)
+        self.output_indices.get(n).copied()
     }
 }
 
@@ -414,7 +414,7 @@ impl<R: RngCore + CryptoRng> Builder<R> {
 
             self.mtx.shielded_spends.push(SpendDescription {
                 cv,
-                anchor: anchor,
+                anchor,
                 nullifier,
                 rk,
                 zkproof,
diff --git a/zcash_primitives/src/transaction/components.rs b/zcash_primitives/src/transaction/components.rs
index 001ff42..c0410c4 100644
--- a/zcash_primitives/src/transaction/components.rs
+++ b/zcash_primitives/src/transaction/components.rs
@@ -166,12 +166,10 @@ impl SpendDescription {
         writer.write_all(&self.zkproof)?;
         match self.spend_auth_sig {
             Some(sig) => sig.write(&mut writer),
-            None => {
-                return Err(io::Error::new(
-                    io::ErrorKind::InvalidInput,
-                    "Missing spend auth signature",
-                ));
-            }
+            None => Err(io::Error::new(
+                io::ErrorKind::InvalidInput,
+                "Missing spend auth signature",
+            )),
         }
     }
 }
@@ -347,23 +345,20 @@ impl JSDescription {
             .map(|mac| reader.read_exact(mac))
             .collect::<io::Result<()>>()?;
 
-        let proof = match use_groth {
-            true => {
-                // Consensus rules (§4.3):
-                // - Canonical encoding is enforced in librustzcash_sprout_verify()
-                // - Proof validity is enforced in librustzcash_sprout_verify()
-                let mut proof = [0; GROTH_PROOF_SIZE];
-                reader.read_exact(&mut proof)?;
-                SproutProof::Groth(proof)
-            }
-            false => {
-                // Consensus rules (§4.3):
-                // - Canonical encoding is enforced by PHGRProof in zcashd
-                // - Proof validity is enforced by JSDescription::Verify() in zcashd
-                let mut proof = [0; PHGR_PROOF_SIZE];
-                reader.read_exact(&mut proof)?;
-                SproutProof::PHGR(proof)
-            }
+        let proof = if use_groth {
+            // Consensus rules (§4.3):
+            // - Canonical encoding is enforced in librustzcash_sprout_verify()
+            // - Proof validity is enforced in librustzcash_sprout_verify()
+            let mut proof = [0; GROTH_PROOF_SIZE];
+            reader.read_exact(&mut proof)?;
+            SproutProof::Groth(proof)
+        } else {
+            // Consensus rules (§4.3):
+            // - Canonical encoding is enforced by PHGRProof in zcashd
+            // - Proof validity is enforced by JSDescription::Verify() in zcashd
+            let mut proof = [0; PHGR_PROOF_SIZE];
+            reader.read_exact(&mut proof)?;
+            SproutProof::PHGR(proof)
         };
 
         let mut ciphertexts = [[0; 601]; ZC_NUM_JS_OUTPUTS];
diff --git a/zcash_primitives/src/transaction/mod.rs b/zcash_primitives/src/transaction/mod.rs
index 567d689..10e935b 100644
--- a/zcash_primitives/src/transaction/mod.rs
+++ b/zcash_primitives/src/transaction/mod.rs
@@ -29,7 +29,7 @@ pub struct TxId(pub [u8; 32]);
 
 impl fmt::Display for TxId {
     fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
-        let mut data = self.0.clone();
+        let mut data = self.0;
         data.reverse();
         formatter.write_str(&hex::encode(data))
     }
@@ -164,9 +164,10 @@ impl Transaction {
         let overwintered = (header >> 31) == 1;
         let version = header & 0x7FFFFFFF;
 
-        let version_group_id = match overwintered {
-            true => reader.read_u32::<LittleEndian>()?,
-            false => 0,
+        let version_group_id = if overwintered {
+            reader.read_u32::<LittleEndian>()?
+        } else {
+            0
         };
 
         let is_overwinter_v3 = overwintered
@@ -185,9 +186,10 @@ impl Transaction {
         let vin = Vector::read(&mut reader, TxIn::read)?;
         let vout = Vector::read(&mut reader, TxOut::read)?;
         let lock_time = reader.read_u32::<LittleEndian>()?;
-        let expiry_height = match is_overwinter_v3 || is_sapling_v4 {
-            true => reader.read_u32::<LittleEndian>()?,
-            false => 0,
+        let expiry_height = if is_overwinter_v3 || is_sapling_v4 {
+            reader.read_u32::<LittleEndian>()?
+        } else {
+            0
         };
 
         let (value_balance, shielded_spends, shielded_outputs) = if is_sapling_v4 {
@@ -223,9 +225,10 @@ impl Transaction {
         };
 
         let binding_sig =
-            match is_sapling_v4 && !(shielded_spends.is_empty() && shielded_outputs.is_empty()) {
-                true => Some(Signature::read(&mut reader)?),
-                false => None,
+            if is_sapling_v4 && !(shielded_spends.is_empty() && shielded_outputs.is_empty()) {
+                Some(Signature::read(&mut reader)?)
+            } else {
+                None
             };
 
         Transaction::from_data(TransactionData {
diff --git a/zcash_primitives/src/transaction/sighash.rs b/zcash_primitives/src/transaction/sighash.rs
index 1b05658..41c6da2 100644
--- a/zcash_primitives/src/transaction/sighash.rs
+++ b/zcash_primitives/src/transaction/sighash.rs
@@ -9,13 +9,13 @@ use super::{
 };
 use crate::legacy::Script;
 
-const ZCASH_SIGHASH_PERSONALIZATION_PREFIX: &'static [u8; 12] = b"ZcashSigHash";
-const ZCASH_PREVOUTS_HASH_PERSONALIZATION: &'static [u8; 16] = b"ZcashPrevoutHash";
-const ZCASH_SEQUENCE_HASH_PERSONALIZATION: &'static [u8; 16] = b"ZcashSequencHash";
-const ZCASH_OUTPUTS_HASH_PERSONALIZATION: &'static [u8; 16] = b"ZcashOutputsHash";
-const ZCASH_JOINSPLITS_HASH_PERSONALIZATION: &'static [u8; 16] = b"ZcashJSplitsHash";
-const ZCASH_SHIELDED_SPENDS_HASH_PERSONALIZATION: &'static [u8; 16] = b"ZcashSSpendsHash";
-const ZCASH_SHIELDED_OUTPUTS_HASH_PERSONALIZATION: &'static [u8; 16] = b"ZcashSOutputHash";
+const ZCASH_SIGHASH_PERSONALIZATION_PREFIX: &[u8; 12] = b"ZcashSigHash";
+const ZCASH_PREVOUTS_HASH_PERSONALIZATION: &[u8; 16] = b"ZcashPrevoutHash";
+const ZCASH_SEQUENCE_HASH_PERSONALIZATION: &[u8; 16] = b"ZcashSequencHash";
+const ZCASH_OUTPUTS_HASH_PERSONALIZATION: &[u8; 16] = b"ZcashOutputsHash";
+const ZCASH_JOINSPLITS_HASH_PERSONALIZATION: &[u8; 16] = b"ZcashJSplitsHash";
+const ZCASH_SHIELDED_SPENDS_HASH_PERSONALIZATION: &[u8; 16] = b"ZcashSSpendsHash";
+const ZCASH_SHIELDED_OUTPUTS_HASH_PERSONALIZATION: &[u8; 16] = b"ZcashSOutputHash";
 
 pub const SIGHASH_ALL: u32 = 1;
 const SIGHASH_NONE: u32 = 2;
diff --git a/zcash_primitives/src/zip32.rs b/zcash_primitives/src/zip32.rs
index 8788809..7cd6148 100644
--- a/zcash_primitives/src/zip32.rs
+++ b/zcash_primitives/src/zip32.rs
@@ -16,8 +16,8 @@ use crate::{
     JUBJUB,
 };
 
-pub const ZIP32_SAPLING_MASTER_PERSONALIZATION: &'static [u8; 16] = b"ZcashIP32Sapling";
-pub const ZIP32_SAPLING_FVFP_PERSONALIZATION: &'static [u8; 16] = b"ZcashSaplingFVFP";
+pub const ZIP32_SAPLING_MASTER_PERSONALIZATION: &[u8; 16] = b"ZcashIP32Sapling";
+pub const ZIP32_SAPLING_FVFP_PERSONALIZATION: &[u8; 16] = b"ZcashSaplingFVFP";
 
 // Common helper functions
 
@@ -83,9 +83,9 @@ impl ChildIndex {
     }
 
     fn to_index(&self) -> u32 {
-        match self {
-            &ChildIndex::Hardened(i) => i + (1 << 31),
-            &ChildIndex::NonHardened(i) => i,
+        match *self {
+            ChildIndex::Hardened(i) => i + (1 << 31),
+            ChildIndex::NonHardened(i) => i,
         }
     }
 }

From 91541675e200bfc9f51d4327a4927fda846a2597 Mon Sep 17 00:00:00 2001
From: Jack Grigg <jack@z.cash>
Date: Fri, 2 Aug 2019 11:40:10 +0100
Subject: [PATCH 4/8] Address various clippy warnings/errors in zcash_proofs

---
 zcash_proofs/src/circuit/ecc.rs           | 16 +++++-----
 zcash_proofs/src/circuit/pedersen_hash.rs |  4 +--
 zcash_proofs/src/circuit/sapling.rs       |  6 ++--
 zcash_proofs/src/circuit/sprout/input.rs  |  4 +--
 zcash_proofs/src/circuit/sprout/mod.rs    | 37 +++++++++--------------
 zcash_proofs/src/circuit/sprout/output.rs |  4 +--
 zcash_proofs/src/hashreader.rs            |  2 +-
 zcash_proofs/src/sapling/prover.rs        | 12 ++++----
 8 files changed, 39 insertions(+), 46 deletions(-)

diff --git a/zcash_proofs/src/circuit/ecc.rs b/zcash_proofs/src/circuit/ecc.rs
index 4c07829..76b837d 100644
--- a/zcash_proofs/src/circuit/ecc.rs
+++ b/zcash_proofs/src/circuit/ecc.rs
@@ -41,16 +41,16 @@ where
     {
         let chunk_a = chunk
             .get(0)
-            .map(|e| e.clone())
-            .unwrap_or(Boolean::constant(false));
+            .cloned()
+            .unwrap_or_else(|| Boolean::constant(false));
         let chunk_b = chunk
             .get(1)
-            .map(|e| e.clone())
-            .unwrap_or(Boolean::constant(false));
+            .cloned()
+            .unwrap_or_else(|| Boolean::constant(false));
         let chunk_c = chunk
             .get(2)
-            .map(|e| e.clone())
-            .unwrap_or(Boolean::constant(false));
+            .cloned()
+            .unwrap_or_else(|| Boolean::constant(false));
 
         let (x, y) = lookup3_xy(
             cs.namespace(|| format!("window table lookup {}", i)),
@@ -58,7 +58,7 @@ where
             window,
         )?;
 
-        let p = EdwardsPoint { x: x, y: y };
+        let p = EdwardsPoint { x, y };
 
         if result.is_none() {
             result = Some(p);
@@ -570,7 +570,7 @@ impl<E: JubjubEngine> MontgomeryPoint<E> {
     /// on the curve. Useful for constants and
     /// window table lookups.
     pub fn interpret_unchecked(x: Num<E>, y: Num<E>) -> Self {
-        MontgomeryPoint { x: x, y: y }
+        MontgomeryPoint { x, y }
     }
 
     /// Performs an affine point addition, not defined for
diff --git a/zcash_proofs/src/circuit/pedersen_hash.rs b/zcash_proofs/src/circuit/pedersen_hash.rs
index 326d3ce..e77d28b 100644
--- a/zcash_proofs/src/circuit/pedersen_hash.rs
+++ b/zcash_proofs/src/circuit/pedersen_hash.rs
@@ -9,7 +9,7 @@ fn get_constant_bools(person: &Personalization) -> Vec<Boolean> {
     person
         .get_bits()
         .into_iter()
-        .map(|e| Boolean::constant(e))
+        .map(Boolean::constant)
         .collect()
 }
 
@@ -65,7 +65,7 @@ where
 
             segment_windows = &segment_windows[1..];
 
-            if segment_windows.len() == 0 {
+            if segment_windows.is_empty() {
                 break;
             }
 
diff --git a/zcash_proofs/src/circuit/sapling.rs b/zcash_proofs/src/circuit/sapling.rs
index 0554ff4..d43a628 100644
--- a/zcash_proofs/src/circuit/sapling.rs
+++ b/zcash_proofs/src/circuit/sapling.rs
@@ -150,7 +150,7 @@ impl<'a, E: JubjubEngine> Circuit<E> for Spend<'a, E> {
             // Witness nsk as bits
             let nsk = boolean::field_into_boolean_vec_le(
                 cs.namespace(|| "nsk"),
-                self.proof_generation_key.as_ref().map(|k| k.nsk.clone()),
+                self.proof_generation_key.as_ref().map(|k| k.nsk),
             )?;
 
             // NB: We don't ensure that the bit representation of nsk
@@ -642,7 +642,7 @@ fn test_input_circuit_with_bls12_381() {
             let mut cs = TestConstraintSystem::<Bls12>::new();
 
             let instance = Spend {
-                params: params,
+                params,
                 value_commitment: Some(value_commitment.clone()),
                 proof_generation_key: Some(proof_generation_key.clone()),
                 payment_address: Some(payment_address.clone()),
@@ -738,7 +738,7 @@ fn test_output_circuit_with_bls12_381() {
             let mut cs = TestConstraintSystem::<Bls12>::new();
 
             let instance = Output {
-                params: params,
+                params,
                 value_commitment: Some(value_commitment.clone()),
                 payment_address: Some(payment_address.clone()),
                 commitment_randomness: Some(commitment_randomness),
diff --git a/zcash_proofs/src/circuit/sprout/input.rs b/zcash_proofs/src/circuit/sprout/input.rs
index ad6091f..a2726d4 100644
--- a/zcash_proofs/src/circuit/sprout/input.rs
+++ b/zcash_proofs/src/circuit/sprout/input.rs
@@ -54,7 +54,7 @@ impl InputNote {
         // Witness into the merkle tree
         let mut cur = cm.clone();
 
-        for (i, layer) in auth_path.into_iter().enumerate() {
+        for (i, layer) in auth_path.iter().enumerate() {
             let cs = &mut cs.namespace(|| format!("layer {}", i));
 
             let cur_is_right = AllocatedBit::alloc(
@@ -112,7 +112,7 @@ impl InputNote {
             );
         }
 
-        Ok(InputNote { mac: mac, nf: nf })
+        Ok(InputNote { mac, nf })
     }
 }
 
diff --git a/zcash_proofs/src/circuit/sprout/mod.rs b/zcash_proofs/src/circuit/sprout/mod.rs
index 358e1bb..f72d792 100644
--- a/zcash_proofs/src/circuit/sprout/mod.rs
+++ b/zcash_proofs/src/circuit/sprout/mod.rs
@@ -234,10 +234,7 @@ impl NoteValue {
             )?);
         }
 
-        Ok(NoteValue {
-            value: value,
-            bits: bits,
-        })
+        Ok(NoteValue { value, bits })
     }
 
     /// Encodes the bits of the value into little-endian
@@ -247,7 +244,7 @@ impl NoteValue {
             .chunks(8)
             .flat_map(|v| v.iter().rev())
             .cloned()
-            .map(|e| Boolean::from(e))
+            .map(Boolean::from)
             .collect()
     }
 
@@ -379,11 +376,11 @@ fn test_sprout_constraints() {
             let a_sk = Some(SpendingKey(get_u256(&mut test_vector)));
 
             inputs.push(JSInput {
-                value: value,
-                a_sk: a_sk,
-                rho: rho,
-                r: r,
-                auth_path: auth_path,
+                value,
+                a_sk,
+                rho,
+                r,
+                auth_path,
             });
         }
 
@@ -395,11 +392,7 @@ fn test_sprout_constraints() {
             get_u256(&mut test_vector);
             let r = Some(CommitmentRandomness(get_u256(&mut test_vector)));
 
-            outputs.push(JSOutput {
-                value: value,
-                a_pk: a_pk,
-                r: r,
-            });
+            outputs.push(JSOutput { value, a_pk, r });
         }
 
         let vpub_old = Some(test_vector.read_u64::<LittleEndian>().unwrap());
@@ -415,13 +408,13 @@ fn test_sprout_constraints() {
         let mac2 = get_u256(&mut test_vector);
 
         let js = JoinSplit {
-            vpub_old: vpub_old,
-            vpub_new: vpub_new,
-            h_sig: h_sig,
-            phi: phi,
-            inputs: inputs,
-            outputs: outputs,
-            rt: rt,
+            vpub_old,
+            vpub_new,
+            h_sig,
+            phi,
+            inputs,
+            outputs,
+            rt,
         };
 
         js.synthesize(&mut cs).unwrap();
diff --git a/zcash_proofs/src/circuit/sprout/output.rs b/zcash_proofs/src/circuit/sprout/output.rs
index a9a1e48..73a9851 100644
--- a/zcash_proofs/src/circuit/sprout/output.rs
+++ b/zcash_proofs/src/circuit/sprout/output.rs
@@ -11,7 +11,7 @@ pub struct OutputNote {
 }
 
 impl OutputNote {
-    pub fn compute<'a, E, CS>(
+    pub fn compute<E, CS>(
         mut cs: CS,
         a_pk: Option<PayingKey>,
         value: &NoteValue,
@@ -41,6 +41,6 @@ impl OutputNote {
             &r,
         )?;
 
-        Ok(OutputNote { cm: cm })
+        Ok(OutputNote { cm })
     }
 }
diff --git a/zcash_proofs/src/hashreader.rs b/zcash_proofs/src/hashreader.rs
index dbe686f..f8487b8 100644
--- a/zcash_proofs/src/hashreader.rs
+++ b/zcash_proofs/src/hashreader.rs
@@ -11,7 +11,7 @@ impl<R: Read> HashReader<R> {
     /// Construct a new `HashReader` given an existing `reader` by value.
     pub fn new(reader: R) -> Self {
         HashReader {
-            reader: reader,
+            reader,
             hasher: State::new(),
         }
     }
diff --git a/zcash_proofs/src/sapling/prover.rs b/zcash_proofs/src/sapling/prover.rs
index 283e76b..e5116c6 100644
--- a/zcash_proofs/src/sapling/prover.rs
+++ b/zcash_proofs/src/sapling/prover.rs
@@ -65,7 +65,7 @@ impl SaplingProvingContext {
 
         // Accumulate the value commitment randomness in the context
         {
-            let mut tmp = rcv.clone();
+            let mut tmp = rcv;
             tmp.add_assign(&self.bsk);
 
             // Update the context
@@ -74,7 +74,7 @@ impl SaplingProvingContext {
 
         // Construct the value commitment
         let value_commitment = ValueCommitment::<Bls12> {
-            value: value,
+            value,
             randomness: rcv,
         };
 
@@ -96,7 +96,7 @@ impl SaplingProvingContext {
 
         // Let's compute the nullifier while we have the position
         let note = Note {
-            value: value,
+            value,
             g_d: diversifier
                 .g_d::<Bls12>(params)
                 .expect("was a valid diversifier before"),
@@ -200,7 +200,7 @@ impl SaplingProvingContext {
 
         // Accumulate the value commitment randomness in the context
         {
-            let mut tmp = rcv.clone();
+            let mut tmp = rcv;
             tmp.negate(); // Outputs subtract from the total.
             tmp.add_assign(&self.bsk);
 
@@ -210,7 +210,7 @@ impl SaplingProvingContext {
 
         // Construct the value commitment for the proof instance
         let value_commitment = ValueCommitment::<Bls12> {
-            value: value,
+            value,
             randomness: rcv,
         };
 
@@ -220,7 +220,7 @@ impl SaplingProvingContext {
             value_commitment: Some(value_commitment.clone()),
             payment_address: Some(payment_address.clone()),
             commitment_randomness: Some(rcm),
-            esk: Some(esk.clone()),
+            esk: Some(esk),
         };
 
         // Create proof

From fe93f2ff6b385f9f30bf3c278351d1d1f162a9bb Mon Sep 17 00:00:00 2001
From: Jack Grigg <jack@z.cash>
Date: Fri, 2 Aug 2019 12:00:15 +0100
Subject: [PATCH 5/8] Rename into_ -> to_ where &self is used.

---
 bellman/src/gadgets/num.rs                  | 10 +++---
 librustzcash/src/tests/key_agreement.rs     |  2 +-
 librustzcash/src/tests/key_components.rs    |  4 +--
 zcash_primitives/src/jubjub/edwards.rs      |  6 ++--
 zcash_primitives/src/jubjub/mod.rs          |  4 +--
 zcash_primitives/src/jubjub/montgomery.rs   |  4 +--
 zcash_primitives/src/jubjub/tests.rs        | 12 +++----
 zcash_primitives/src/primitives.rs          |  6 ++--
 zcash_primitives/src/sapling.rs             |  2 +-
 zcash_primitives/src/transaction/builder.rs |  2 +-
 zcash_primitives/src/zip32.rs               |  2 +-
 zcash_proofs/examples/bench.rs              |  4 +--
 zcash_proofs/src/circuit/ecc.rs             | 38 ++++++++++-----------
 zcash_proofs/src/circuit/pedersen_hash.rs   |  4 +--
 zcash_proofs/src/circuit/sapling.rs         | 24 ++++++-------
 zcash_proofs/src/sapling/prover.rs          |  8 ++---
 zcash_proofs/src/sapling/verifier.rs        |  8 ++---
 17 files changed, 70 insertions(+), 70 deletions(-)

diff --git a/bellman/src/gadgets/num.rs b/bellman/src/gadgets/num.rs
index 81f4fb3..eecccef 100644
--- a/bellman/src/gadgets/num.rs
+++ b/bellman/src/gadgets/num.rs
@@ -66,7 +66,7 @@ impl<E: Engine> AllocatedNum<E> {
     /// order, requiring that the representation
     /// strictly exists "in the field" (i.e., a
     /// congruency is not allowed.)
-    pub fn into_bits_le_strict<CS>(&self, mut cs: CS) -> Result<Vec<Boolean>, SynthesisError>
+    pub fn to_bits_le_strict<CS>(&self, mut cs: CS) -> Result<Vec<Boolean>, SynthesisError>
     where
         CS: ConstraintSystem<E>,
     {
@@ -189,7 +189,7 @@ impl<E: Engine> AllocatedNum<E> {
     /// Convert the allocated number into its little-endian representation.
     /// Note that this does not strongly enforce that the commitment is
     /// "in the field."
-    pub fn into_bits_le<CS>(&self, mut cs: CS) -> Result<Vec<Boolean>, SynthesisError>
+    pub fn to_bits_le<CS>(&self, mut cs: CS) -> Result<Vec<Boolean>, SynthesisError>
     where
         CS: ConstraintSystem<E>,
     {
@@ -522,7 +522,7 @@ mod test {
         let mut cs = TestConstraintSystem::<Bls12>::new();
 
         let n = AllocatedNum::alloc(&mut cs, || Ok(negone)).unwrap();
-        n.into_bits_le_strict(&mut cs).unwrap();
+        n.to_bits_le_strict(&mut cs).unwrap();
 
         assert!(cs.is_satisfied());
 
@@ -550,9 +550,9 @@ mod test {
             let n = AllocatedNum::alloc(&mut cs, || Ok(r)).unwrap();
 
             let bits = if i % 2 == 0 {
-                n.into_bits_le(&mut cs).unwrap()
+                n.to_bits_le(&mut cs).unwrap()
             } else {
-                n.into_bits_le_strict(&mut cs).unwrap()
+                n.to_bits_le_strict(&mut cs).unwrap()
             };
 
             assert!(cs.is_satisfied());
diff --git a/librustzcash/src/tests/key_agreement.rs b/librustzcash/src/tests/key_agreement.rs
index d942e10..8f2c273 100644
--- a/librustzcash/src/tests/key_agreement.rs
+++ b/librustzcash/src/tests/key_agreement.rs
@@ -25,7 +25,7 @@ fn test_key_agreement() {
     let addr = loop {
         let mut d = [0; 11];
         rng.fill_bytes(&mut d);
-        match vk.into_payment_address(Diversifier(d), &params) {
+        match vk.to_payment_address(Diversifier(d), &params) {
             Some(a) => break a,
             None => {}
         }
diff --git a/librustzcash/src/tests/key_components.rs b/librustzcash/src/tests/key_components.rs
index a034b9f..a15a40a 100644
--- a/librustzcash/src/tests/key_components.rs
+++ b/librustzcash/src/tests/key_components.rs
@@ -678,7 +678,7 @@ fn key_components() {
         }
 
         let pgk = ProofGenerationKey { ak, nsk };
-        let fvk = pgk.into_viewing_key(&JUBJUB);
+        let fvk = pgk.to_viewing_key(&JUBJUB);
         {
             let mut vec = Vec::new();
             fvk.nk.write(&mut vec).unwrap();
@@ -704,7 +704,7 @@ fn key_components() {
         let diversifier = Diversifier(tv.default_d);
         assert!(librustzcash_check_diversifier(&tv.default_d));
 
-        let addr = fvk.into_payment_address(diversifier, &JUBJUB).unwrap();
+        let addr = fvk.to_payment_address(diversifier, &JUBJUB).unwrap();
         {
             let mut vec = Vec::new();
             addr.pk_d.write(&mut vec).unwrap();
diff --git a/zcash_primitives/src/jubjub/edwards.rs b/zcash_primitives/src/jubjub/edwards.rs
index 233bfb7..9ef50a2 100644
--- a/zcash_primitives/src/jubjub/edwards.rs
+++ b/zcash_primitives/src/jubjub/edwards.rs
@@ -168,7 +168,7 @@ impl<E: JubjubEngine> Point<E, Unknown> {
 
 impl<E: JubjubEngine, Subgroup> Point<E, Subgroup> {
     pub fn write<W: Write>(&self, writer: W) -> io::Result<()> {
-        let (x, y) = self.into_xy();
+        let (x, y) = self.to_xy();
 
         assert_eq!(E::Fr::NUM_BITS, 255);
 
@@ -183,7 +183,7 @@ impl<E: JubjubEngine, Subgroup> Point<E, Subgroup> {
 
     /// Convert from a Montgomery point
     pub fn from_montgomery(m: &montgomery::Point<E, Subgroup>, params: &E::Params) -> Self {
-        match m.into_xy() {
+        match m.to_xy() {
             None => {
                 // Map the point at infinity to the neutral element.
                 Point::zero()
@@ -306,7 +306,7 @@ impl<E: JubjubEngine, Subgroup> Point<E, Subgroup> {
         }
     }
 
-    pub fn into_xy(&self) -> (E::Fr, E::Fr) {
+    pub fn to_xy(&self) -> (E::Fr, E::Fr) {
         let zinv = self.z.inverse().unwrap();
 
         let mut x = self.x;
diff --git a/zcash_primitives/src/jubjub/mod.rs b/zcash_primitives/src/jubjub/mod.rs
index 624592e..40938f3 100644
--- a/zcash_primitives/src/jubjub/mod.rs
+++ b/zcash_primitives/src/jubjub/mod.rs
@@ -384,7 +384,7 @@ impl JubjubBls12 {
 
                     // coeffs = g, g*2, g*3, g*4
                     for _ in 0..4 {
-                        coeffs.push(g.into_xy().expect("cannot produce O"));
+                        coeffs.push(g.to_xy().expect("cannot produce O"));
                         g = g.add(&gen, &tmp_params);
                     }
                     windows.push(coeffs);
@@ -411,7 +411,7 @@ impl JubjubBls12 {
                     let mut coeffs = vec![(Fr::zero(), Fr::one())];
                     let mut g = gen.clone();
                     for _ in 0..7 {
-                        coeffs.push(g.into_xy());
+                        coeffs.push(g.to_xy());
                         g = g.add(&gen, &tmp_params);
                     }
                     windows.push(coeffs);
diff --git a/zcash_primitives/src/jubjub/montgomery.rs b/zcash_primitives/src/jubjub/montgomery.rs
index 0ebedd2..4e6c5e1 100644
--- a/zcash_primitives/src/jubjub/montgomery.rs
+++ b/zcash_primitives/src/jubjub/montgomery.rs
@@ -98,7 +98,7 @@ impl<E: JubjubEngine> Point<E, Unknown> {
 impl<E: JubjubEngine, Subgroup> Point<E, Subgroup> {
     /// Convert from an Edwards point
     pub fn from_edwards(e: &edwards::Point<E, Subgroup>, params: &E::Params) -> Self {
-        let (x, y) = e.into_xy();
+        let (x, y) = e.to_xy();
 
         if y == E::Fr::one() {
             // The only solution for y = 1 is x = 0. (0, 1) is
@@ -177,7 +177,7 @@ impl<E: JubjubEngine, Subgroup> Point<E, Subgroup> {
         }
     }
 
-    pub fn into_xy(&self) -> Option<(E::Fr, E::Fr)> {
+    pub fn to_xy(&self) -> Option<(E::Fr, E::Fr)> {
         if self.infinity {
             None
         } else {
diff --git a/zcash_primitives/src/jubjub/tests.rs b/zcash_primitives/src/jubjub/tests.rs
index 1b4f8d1..b2c12ae 100644
--- a/zcash_primitives/src/jubjub/tests.rs
+++ b/zcash_primitives/src/jubjub/tests.rs
@@ -119,13 +119,13 @@ fn test_mul_associativity<E: JubjubEngine>(params: &E::Params) {
         assert!(res2 == res3);
         assert!(res3 == res4);
 
-        let (x, y) = res1.into_xy();
+        let (x, y) = res1.to_xy();
         assert!(is_on_twisted_edwards_curve(x, y, params));
 
-        let (x, y) = res2.into_xy();
+        let (x, y) = res2.to_xy();
         assert!(is_on_twisted_edwards_curve(x, y, params));
 
-        let (x, y) = res3.into_xy();
+        let (x, y) = res3.to_xy();
         assert!(is_on_twisted_edwards_curve(x, y, params));
     }
 }
@@ -238,7 +238,7 @@ fn test_get_for<E: JubjubEngine>(params: &E::Params) {
         let sign = rng.next_u32() % 2 == 1;
 
         if let Some(mut p) = edwards::Point::<E, _>::get_for_y(y, sign, params) {
-            assert!(p.into_xy().0.into_repr().is_odd() == sign);
+            assert!(p.to_xy().0.into_repr().is_odd() == sign);
             p = p.negate();
             assert!(edwards::Point::<E, _>::get_for_y(y, !sign, params).unwrap() == p);
         }
@@ -274,12 +274,12 @@ fn test_rand<E: JubjubEngine>(params: &E::Params) {
         let e = edwards::Point::<E, _>::rand(rng, params);
 
         {
-            let (x, y) = p.into_xy().unwrap();
+            let (x, y) = p.to_xy().unwrap();
             assert!(is_on_mont_curve(x, y, params));
         }
 
         {
-            let (x, y) = e.into_xy();
+            let (x, y) = e.to_xy();
             assert!(is_on_twisted_edwards_curve(x, y, params));
         }
     }
diff --git a/zcash_primitives/src/primitives.rs b/zcash_primitives/src/primitives.rs
index 38a056a..727402d 100644
--- a/zcash_primitives/src/primitives.rs
+++ b/zcash_primitives/src/primitives.rs
@@ -39,7 +39,7 @@ pub struct ProofGenerationKey<E: JubjubEngine> {
 }
 
 impl<E: JubjubEngine> ProofGenerationKey<E> {
-    pub fn into_viewing_key(&self, params: &E::Params) -> ViewingKey<E> {
+    pub fn to_viewing_key(&self, params: &E::Params) -> ViewingKey<E> {
         ViewingKey {
             ak: self.ak.clone(),
             nk: params
@@ -89,7 +89,7 @@ impl<E: JubjubEngine> ViewingKey<E> {
         E::Fs::from_repr(e).expect("should be a valid scalar")
     }
 
-    pub fn into_payment_address(
+    pub fn to_payment_address(
         &self,
         diversifier: Diversifier,
         params: &E::Params,
@@ -242,6 +242,6 @@ impl<E: JubjubEngine> Note<E> {
     pub fn cm(&self, params: &E::Params) -> E::Fr {
         // The commitment is in the prime order subgroup, so mapping the
         // commitment to the x-coordinate is an injective encoding.
-        self.cm_full_point(params).into_xy().0
+        self.cm_full_point(params).to_xy().0
     }
 }
diff --git a/zcash_primitives/src/sapling.rs b/zcash_primitives/src/sapling.rs
index 8b8ef88..4f57a43 100644
--- a/zcash_primitives/src/sapling.rs
+++ b/zcash_primitives/src/sapling.rs
@@ -42,7 +42,7 @@ pub fn merkle_hash(depth: usize, lhs: &FrRepr, rhs: &FrRepr) -> FrRepr {
             .chain(rhs.iter().copied().take(Fr::NUM_BITS as usize)),
         &JUBJUB,
     )
-    .into_xy()
+    .to_xy()
     .0
     .into_repr()
 }
diff --git a/zcash_primitives/src/transaction/builder.rs b/zcash_primitives/src/transaction/builder.rs
index 1f30f99..281ccbf 100644
--- a/zcash_primitives/src/transaction/builder.rs
+++ b/zcash_primitives/src/transaction/builder.rs
@@ -394,7 +394,7 @@ impl<R: RngCore + CryptoRng> Builder<R> {
 
             let mut nullifier = [0u8; 32];
             nullifier.copy_from_slice(&spend.note.nf(
-                &proof_generation_key.into_viewing_key(&JUBJUB),
+                &proof_generation_key.to_viewing_key(&JUBJUB),
                 spend.witness.position,
                 &JUBJUB,
             ));
diff --git a/zcash_primitives/src/zip32.rs b/zcash_primitives/src/zip32.rs
index 7cd6148..e287602 100644
--- a/zcash_primitives/src/zip32.rs
+++ b/zcash_primitives/src/zip32.rs
@@ -434,7 +434,7 @@ impl ExtendedFullViewingKey {
             Ok(ret) => ret,
             Err(()) => return Err(()),
         };
-        match self.fvk.vk.into_payment_address(d_j, &JUBJUB) {
+        match self.fvk.vk.to_payment_address(d_j, &JUBJUB) {
             Some(addr) => Ok((j, addr)),
             None => Err(()),
         }
diff --git a/zcash_proofs/examples/bench.rs b/zcash_proofs/examples/bench.rs
index 62beb0a..2f48786 100644
--- a/zcash_proofs/examples/bench.rs
+++ b/zcash_proofs/examples/bench.rs
@@ -50,7 +50,7 @@ fn main() {
             nsk: nsk.clone(),
         };
 
-        let viewing_key = proof_generation_key.into_viewing_key(jubjub_params);
+        let viewing_key = proof_generation_key.to_viewing_key(jubjub_params);
 
         let payment_address;
 
@@ -61,7 +61,7 @@ fn main() {
                 Diversifier(d)
             };
 
-            if let Some(p) = viewing_key.into_payment_address(diversifier, jubjub_params) {
+            if let Some(p) = viewing_key.to_payment_address(diversifier, jubjub_params) {
                 payment_address = p;
                 break;
             }
diff --git a/zcash_proofs/src/circuit/ecc.rs b/zcash_proofs/src/circuit/ecc.rs
index 76b837d..ef5bedf 100644
--- a/zcash_proofs/src/circuit/ecc.rs
+++ b/zcash_proofs/src/circuit/ecc.rs
@@ -121,9 +121,9 @@ impl<E: JubjubEngine> EdwardsPoint<E> {
     {
         let mut tmp = vec![];
 
-        let x = self.x.into_bits_le_strict(cs.namespace(|| "unpack x"))?;
+        let x = self.x.to_bits_le_strict(cs.namespace(|| "unpack x"))?;
 
-        let y = self.y.into_bits_le_strict(cs.namespace(|| "unpack y"))?;
+        let y = self.y.to_bits_le_strict(cs.namespace(|| "unpack y"))?;
 
         tmp.extend(y);
         tmp.push(x[0].clone());
@@ -141,7 +141,7 @@ impl<E: JubjubEngine> EdwardsPoint<E> {
     where
         CS: ConstraintSystem<E>,
     {
-        let p = p.map(|p| p.into_xy());
+        let p = p.map(|p| p.to_xy());
 
         // Allocate x
         let x = AllocatedNum::alloc(cs.namespace(|| "x"), || Ok(p.get()?.0))?;
@@ -688,8 +688,8 @@ mod test {
             let mut cs = TestConstraintSystem::<Bls12>::new();
 
             let p = montgomery::Point::<Bls12, _>::rand(rng, params);
-            let (u, v) = edwards::Point::from_montgomery(&p, params).into_xy();
-            let (x, y) = p.into_xy().unwrap();
+            let (u, v) = edwards::Point::from_montgomery(&p, params).to_xy();
+            let (x, y) = p.to_xy().unwrap();
 
             let numx = AllocatedNum::alloc(cs.namespace(|| "mont x"), || Ok(x)).unwrap();
             let numy = AllocatedNum::alloc(cs.namespace(|| "mont y"), || Ok(y)).unwrap();
@@ -728,7 +728,7 @@ mod test {
             let mut cs = TestConstraintSystem::<Bls12>::new();
             let q = EdwardsPoint::witness(&mut cs, Some(p.clone()), &params).unwrap();
 
-            let p = p.into_xy();
+            let p = p.to_xy();
 
             assert!(cs.is_satisfied());
             assert_eq!(q.x.get_value().unwrap(), p.0);
@@ -737,7 +737,7 @@ mod test {
 
         for _ in 0..100 {
             let p = edwards::Point::<Bls12, _>::rand(rng, &params);
-            let (x, y) = p.into_xy();
+            let (x, y) = p.to_xy();
 
             let mut cs = TestConstraintSystem::<Bls12>::new();
             let numx = AllocatedNum::alloc(cs.namespace(|| "x"), || Ok(x)).unwrap();
@@ -779,7 +779,7 @@ mod test {
             let p = params.generator(FixedGenerators::NoteCommitmentRandomness);
             let s = Fs::random(rng);
             let q = p.mul(s, params);
-            let (x1, y1) = q.into_xy();
+            let (x1, y1) = q.to_xy();
 
             let mut s_bits = BitIterator::new(s.into_repr()).collect::<Vec<_>>();
             s_bits.reverse();
@@ -823,8 +823,8 @@ mod test {
             let s = Fs::random(rng);
             let q = p.mul(s, params);
 
-            let (x0, y0) = p.into_xy();
-            let (x1, y1) = q.into_xy();
+            let (x0, y0) = p.to_xy();
+            let (x1, y1) = q.to_xy();
 
             let num_x0 = AllocatedNum::alloc(cs.namespace(|| "x0"), || Ok(x0)).unwrap();
             let num_y0 = AllocatedNum::alloc(cs.namespace(|| "y0"), || Ok(y0)).unwrap();
@@ -873,7 +873,7 @@ mod test {
 
             let p = edwards::Point::<Bls12, _>::rand(rng, params);
 
-            let (x0, y0) = p.into_xy();
+            let (x0, y0) = p.to_xy();
 
             let num_x0 = AllocatedNum::alloc(cs.namespace(|| "x0"), || Ok(x0)).unwrap();
             let num_y0 = AllocatedNum::alloc(cs.namespace(|| "y0"), || Ok(y0)).unwrap();
@@ -941,9 +941,9 @@ mod test {
 
             let p3 = p1.add(&p2, params);
 
-            let (x0, y0) = p1.into_xy();
-            let (x1, y1) = p2.into_xy();
-            let (x2, y2) = p3.into_xy();
+            let (x0, y0) = p1.to_xy();
+            let (x1, y1) = p2.to_xy();
+            let (x2, y2) = p3.to_xy();
 
             let mut cs = TestConstraintSystem::<Bls12>::new();
 
@@ -1002,8 +1002,8 @@ mod test {
             let p1 = edwards::Point::<Bls12, _>::rand(rng, params);
             let p2 = p1.double(params);
 
-            let (x0, y0) = p1.into_xy();
-            let (x1, y1) = p2.into_xy();
+            let (x0, y0) = p1.to_xy();
+            let (x1, y1) = p2.to_xy();
 
             let mut cs = TestConstraintSystem::<Bls12>::new();
 
@@ -1053,9 +1053,9 @@ mod test {
 
             let p3 = p1.add(&p2, params);
 
-            let (x0, y0) = p1.into_xy().unwrap();
-            let (x1, y1) = p2.into_xy().unwrap();
-            let (x2, y2) = p3.into_xy().unwrap();
+            let (x0, y0) = p1.to_xy().unwrap();
+            let (x1, y1) = p2.to_xy().unwrap();
+            let (x2, y2) = p3.to_xy().unwrap();
 
             let mut cs = TestConstraintSystem::<Bls12>::new();
 
diff --git a/zcash_proofs/src/circuit/pedersen_hash.rs b/zcash_proofs/src/circuit/pedersen_hash.rs
index e77d28b..409f30e 100644
--- a/zcash_proofs/src/circuit/pedersen_hash.rs
+++ b/zcash_proofs/src/circuit/pedersen_hash.rs
@@ -189,7 +189,7 @@ mod test {
                     input.clone().into_iter(),
                     params,
                 )
-                .into_xy();
+                .to_xy();
 
                 assert_eq!(res.get_x().get_value().unwrap(), expected.0);
                 assert_eq!(res.get_y().get_value().unwrap(), expected.1);
@@ -200,7 +200,7 @@ mod test {
                     input.into_iter(),
                     params,
                 )
-                .into_xy();
+                .to_xy();
 
                 assert!(res.get_x().get_value().unwrap() != unexpected.0);
                 assert!(res.get_y().get_value().unwrap() != unexpected.1);
diff --git a/zcash_proofs/src/circuit/sapling.rs b/zcash_proofs/src/circuit/sapling.rs
index d43a628..de6887b 100644
--- a/zcash_proofs/src/circuit/sapling.rs
+++ b/zcash_proofs/src/circuit/sapling.rs
@@ -336,8 +336,8 @@ impl<'a, E: JubjubEngine> Circuit<E> for Spend<'a, E> {
             // they will be unable to find an authentication path in the
             // tree with high probability.
             let mut preimage = vec![];
-            preimage.extend(xl.into_bits_le(cs.namespace(|| "xl into bits"))?);
-            preimage.extend(xr.into_bits_le(cs.namespace(|| "xr into bits"))?);
+            preimage.extend(xl.to_bits_le(cs.namespace(|| "xl into bits"))?);
+            preimage.extend(xr.to_bits_le(cs.namespace(|| "xr into bits"))?);
 
             // Compute the new subtree value
             cur = pedersen_hash::pedersen_hash(
@@ -464,7 +464,7 @@ impl<'a, E: JubjubEngine> Circuit<E> for Output<'a, E> {
         // they would like.
         {
             // Just grab pk_d from the witness
-            let pk_d = self.payment_address.as_ref().map(|e| e.pk_d.into_xy());
+            let pk_d = self.payment_address.as_ref().map(|e| e.pk_d.to_xy());
 
             // Witness the y-coordinate, encoded as little
             // endian bits (to match the representation)
@@ -567,7 +567,7 @@ fn test_input_circuit_with_bls12_381() {
             nsk: nsk.clone(),
         };
 
-        let viewing_key = proof_generation_key.into_viewing_key(params);
+        let viewing_key = proof_generation_key.to_viewing_key(params);
 
         let payment_address;
 
@@ -578,7 +578,7 @@ fn test_input_circuit_with_bls12_381() {
                 Diversifier(d)
             };
 
-            if let Some(p) = viewing_key.into_payment_address(diversifier, params) {
+            if let Some(p) = viewing_key.to_payment_address(diversifier, params) {
                 payment_address = p;
                 break;
             }
@@ -590,8 +590,8 @@ fn test_input_circuit_with_bls12_381() {
         let ar = fs::Fs::random(rng);
 
         {
-            let rk = viewing_key.rk(ar, params).into_xy();
-            let expected_value_cm = value_commitment.cm(params).into_xy();
+            let rk = viewing_key.rk(ar, params).to_xy();
+            let expected_value_cm = value_commitment.cm(params).to_xy();
             let note = Note {
                 value: value_commitment.value,
                 g_d: g_d.clone(),
@@ -626,7 +626,7 @@ fn test_input_circuit_with_bls12_381() {
                         .chain(rhs.into_iter().take(Fr::NUM_BITS as usize)),
                     params,
                 )
-                .into_xy()
+                .to_xy()
                 .0;
 
                 if b {
@@ -714,7 +714,7 @@ fn test_output_circuit_with_bls12_381() {
             nsk: nsk.clone(),
         };
 
-        let viewing_key = proof_generation_key.into_viewing_key(params);
+        let viewing_key = proof_generation_key.to_viewing_key(params);
 
         let payment_address;
 
@@ -725,7 +725,7 @@ fn test_output_circuit_with_bls12_381() {
                 Diversifier(d)
             };
 
-            if let Some(p) = viewing_key.into_payment_address(diversifier, params) {
+            if let Some(p) = viewing_key.to_payment_address(diversifier, params) {
                 payment_address = p;
                 break;
             }
@@ -759,13 +759,13 @@ fn test_output_circuit_with_bls12_381() {
                 .expect("should be valid")
                 .cm(params);
 
-            let expected_value_cm = value_commitment.cm(params).into_xy();
+            let expected_value_cm = value_commitment.cm(params).to_xy();
 
             let expected_epk = payment_address
                 .g_d(params)
                 .expect("should be valid")
                 .mul(esk, params);
-            let expected_epk_xy = expected_epk.into_xy();
+            let expected_epk_xy = expected_epk.to_xy();
 
             assert_eq!(cs.num_inputs(), 6);
             assert_eq!(cs.get_input(0, "ONE"), Fr::one());
diff --git a/zcash_proofs/src/sapling/prover.rs b/zcash_proofs/src/sapling/prover.rs
index e5116c6..0603424 100644
--- a/zcash_proofs/src/sapling/prover.rs
+++ b/zcash_proofs/src/sapling/prover.rs
@@ -79,10 +79,10 @@ impl SaplingProvingContext {
         };
 
         // Construct the viewing key
-        let viewing_key = proof_generation_key.into_viewing_key(params);
+        let viewing_key = proof_generation_key.to_viewing_key(params);
 
         // Construct the payment address with the viewing key / diversifier
-        let payment_address = match viewing_key.into_payment_address(diversifier, params) {
+        let payment_address = match viewing_key.to_payment_address(diversifier, params) {
             Some(p) => p,
             None => return Err(()),
         };
@@ -130,12 +130,12 @@ impl SaplingProvingContext {
         // Construct public input for circuit
         let mut public_input = [Fr::zero(); 7];
         {
-            let (x, y) = rk.0.into_xy();
+            let (x, y) = rk.0.to_xy();
             public_input[0] = x;
             public_input[1] = y;
         }
         {
-            let (x, y) = value_commitment.cm(params).into_xy();
+            let (x, y) = value_commitment.cm(params).to_xy();
             public_input[2] = x;
             public_input[3] = y;
         }
diff --git a/zcash_proofs/src/sapling/verifier.rs b/zcash_proofs/src/sapling/verifier.rs
index 0801023..5199bd8 100644
--- a/zcash_proofs/src/sapling/verifier.rs
+++ b/zcash_proofs/src/sapling/verifier.rs
@@ -82,12 +82,12 @@ impl SaplingVerificationContext {
         // Construct public input for circuit
         let mut public_input = [Fr::zero(); 7];
         {
-            let (x, y) = rk.0.into_xy();
+            let (x, y) = rk.0.to_xy();
             public_input[0] = x;
             public_input[1] = y;
         }
         {
-            let (x, y) = cv.into_xy();
+            let (x, y) = cv.to_xy();
             public_input[2] = x;
             public_input[3] = y;
         }
@@ -146,12 +146,12 @@ impl SaplingVerificationContext {
         // Construct public input for circuit
         let mut public_input = [Fr::zero(); 5];
         {
-            let (x, y) = cv.into_xy();
+            let (x, y) = cv.to_xy();
             public_input[0] = x;
             public_input[1] = y;
         }
         {
-            let (x, y) = epk.into_xy();
+            let (x, y) = epk.to_xy();
             public_input[2] = x;
             public_input[3] = y;
         }

From 90165486983018853d03eb4a85ec6e0a7287361c Mon Sep 17 00:00:00 2001
From: Jack Grigg <jack@z.cash>
Date: Fri, 2 Aug 2019 12:03:38 +0100
Subject: [PATCH 6/8] Take self directly in into_* functions

---
 bellman/src/gadgets/blake2s.rs  |  2 +-
 bellman/src/gadgets/uint32.rs   | 10 ++++++----
 zcash_proofs/src/circuit/ecc.rs |  2 +-
 3 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/bellman/src/gadgets/blake2s.rs b/bellman/src/gadgets/blake2s.rs
index beefe09..672f139 100644
--- a/bellman/src/gadgets/blake2s.rs
+++ b/bellman/src/gadgets/blake2s.rs
@@ -404,7 +404,7 @@ pub fn blake2s<E: Engine, CS: ConstraintSystem<E>>(
         )?;
     }
 
-    Ok(h.iter().flat_map(|b| b.into_bits()).collect())
+    Ok(h.into_iter().flat_map(|b| b.into_bits()).collect())
 }
 
 #[cfg(test)]
diff --git a/bellman/src/gadgets/uint32.rs b/bellman/src/gadgets/uint32.rs
index 3467400..5a93e75 100644
--- a/bellman/src/gadgets/uint32.rs
+++ b/bellman/src/gadgets/uint32.rs
@@ -72,8 +72,10 @@ impl UInt32 {
         Ok(UInt32 { bits, value })
     }
 
-    pub fn into_bits_be(&self) -> Vec<Boolean> {
-        self.bits.iter().rev().cloned().collect()
+    pub fn into_bits_be(self) -> Vec<Boolean> {
+        let mut ret = self.bits;
+        ret.reverse();
+        ret
     }
 
     pub fn from_bits_be(bits: &[Boolean]) -> Self {
@@ -101,8 +103,8 @@ impl UInt32 {
     }
 
     /// Turns this `UInt32` into its little-endian byte order representation.
-    pub fn into_bits(&self) -> Vec<Boolean> {
-        self.bits.clone()
+    pub fn into_bits(self) -> Vec<Boolean> {
+        self.bits
     }
 
     /// Converts a little-endian byte order representation of bits into a
diff --git a/zcash_proofs/src/circuit/ecc.rs b/zcash_proofs/src/circuit/ecc.rs
index ef5bedf..fa4913a 100644
--- a/zcash_proofs/src/circuit/ecc.rs
+++ b/zcash_proofs/src/circuit/ecc.rs
@@ -508,7 +508,7 @@ impl<E: JubjubEngine> MontgomeryPoint<E> {
     /// a point in the birationally equivalent twisted
     /// Edwards curve.
     pub fn into_edwards<CS>(
-        &self,
+        self,
         mut cs: CS,
         params: &E::Params,
     ) -> Result<EdwardsPoint<E>, SynthesisError>

From 7c1d4d9a5b63330d71884dc78fefcefaf8b384d5 Mon Sep 17 00:00:00 2001
From: Jack Grigg <jack@z.cash>
Date: Sun, 18 Aug 2019 23:56:15 +0100
Subject: [PATCH 7/8] Log distinct error cases in Equihash verification

---
 Cargo.lock                             | 10 ++++++++++
 zcash_primitives/Cargo.toml            |  1 +
 zcash_primitives/src/block/equihash.rs |  7 ++++---
 3 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index d6f658a..623bcc0 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -317,6 +317,14 @@ dependencies = [
  "zcash_proofs 0.0.0",
 ]
 
+[[package]]
+name = "log"
+version = "0.4.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cfg-if 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "nodrop"
 version = "0.1.13"
@@ -535,6 +543,7 @@ dependencies = [
  "hex 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "hex-literal 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "pairing 0.14.2",
  "rand 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand_core 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -594,6 +603,7 @@ dependencies = [
 "checksum hex-literal-impl 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "520870c3213943eb8d7803e80180d12a6c7ceb4ae74602544529d1643dc4ddda"
 "checksum lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "bc5729f27f159ddd61f4df6228e827e86643d4d3e7c32183cb30a1c08f604a14"
 "checksum libc 0.2.61 (registry+https://github.com/rust-lang/crates.io-index)" = "c665266eb592905e8503ba3403020f4b8794d26263f412ca33171600eca9a6fa"
+"checksum log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)" = "14b6052be84e6b71ab17edffc2eeabf5c2c3ae1fdb464aae35ac50c67a44e1f7"
 "checksum nodrop 0.1.13 (registry+https://github.com/rust-lang/crates.io-index)" = "2f9667ddcc6cc8a43afc9b7917599d7216aa09c463919ea32c59ed6cac8bc945"
 "checksum num-bigint 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "57450397855d951f1a41305e54851b1a7b8f5d2e349543a02a2effe25459f718"
 "checksum num-integer 0.1.41 (registry+https://github.com/rust-lang/crates.io-index)" = "b85e541ef8255f6cf42bbfe4ef361305c6c135d10919ecc26126c4e5ae94bc09"
diff --git a/zcash_primitives/Cargo.toml b/zcash_primitives/Cargo.toml
index 5e1bf91..7019dec 100644
--- a/zcash_primitives/Cargo.toml
+++ b/zcash_primitives/Cargo.toml
@@ -16,6 +16,7 @@ ff = { path = "../ff" }
 fpe = "0.2"
 hex = "0.3"
 lazy_static = "1"
+log = "0.4"
 pairing = { path = "../pairing" }
 rand = "0.7"
 rand_core = "0.5"
diff --git a/zcash_primitives/src/block/equihash.rs b/zcash_primitives/src/block/equihash.rs
index 9710dc9..2a3bb66 100644
--- a/zcash_primitives/src/block/equihash.rs
+++ b/zcash_primitives/src/block/equihash.rs
@@ -1,5 +1,6 @@
 use blake2b_simd::{Hash as Blake2bHash, Params as Blake2bParams, State as Blake2bState};
 use byteorder::{BigEndian, LittleEndian, ReadBytesExt, WriteBytesExt};
+use log::error;
 use std::io::Cursor;
 use std::mem::size_of;
 
@@ -196,13 +197,13 @@ fn distinct_indices(a: &Node, b: &Node) -> bool {
 
 fn validate_subtrees(p: &Params, a: &Node, b: &Node) -> bool {
     if !has_collision(a, b, p.collision_byte_length()) {
-        // error!("Invalid solution: invalid collision length between StepRows");
+        error!("Invalid solution: invalid collision length between StepRows");
         false
     } else if b.indices_before(a) {
-        // error!("Invalid solution: Index tree incorrectly ordered");
+        error!("Invalid solution: Index tree incorrectly ordered");
         false
     } else if !distinct_indices(a, b) {
-        // error!("Invalid solution: duplicate indices");
+        error!("Invalid solution: duplicate indices");
         false
     } else {
         true

From 0c7eb84d36e41e562f6a9a092c67d772f46f6fc5 Mon Sep 17 00:00:00 2001
From: Jack Grigg <jack@z.cash>
Date: Mon, 19 Aug 2019 00:21:10 +0100
Subject: [PATCH 8/8] impl FromStr for Memo

Memo::from_str was previously shadowing a built-in trait method.
---
 zcash_primitives/src/note_encryption.rs | 37 +++++++++++++++----------
 1 file changed, 22 insertions(+), 15 deletions(-)

diff --git a/zcash_primitives/src/note_encryption.rs b/zcash_primitives/src/note_encryption.rs
index 0d0e83a..2644016 100644
--- a/zcash_primitives/src/note_encryption.rs
+++ b/zcash_primitives/src/note_encryption.rs
@@ -106,11 +106,6 @@ impl Memo {
         }
     }
 
-    /// Returns a `Memo` containing the given string, or `None` if the string is too long.
-    pub fn from_str(memo: &str) -> Option<Memo> {
-        Memo::from_bytes(memo.as_bytes())
-    }
-
     /// Returns the underlying bytes of the `Memo`.
     pub fn as_bytes(&self) -> &[u8] {
         &self.0[..]
@@ -134,6 +129,15 @@ impl Memo {
     }
 }
 
+impl str::FromStr for Memo {
+    type Err = ();
+
+    /// Returns a `Memo` containing the given string, or an error if the string is too long.
+    fn from_str(memo: &str) -> Result<Self, Self::Err> {
+        Memo::from_bytes(memo.as_bytes()).ok_or(())
+    }
+}
+
 pub fn generate_esk<R: RngCore + CryptoRng>(rng: &mut R) -> Fs {
     // create random 64 byte buffer
     let mut buffer = [0u8; 64];
@@ -557,6 +561,7 @@ mod tests {
     use pairing::bls12_381::{Bls12, Fr, FrRepr};
     use rand_core::{CryptoRng, RngCore};
     use rand_os::OsRng;
+    use std::str::FromStr;
 
     use super::{
         kdf_sapling, prf_ock, sapling_ka_agree, try_sapling_compact_note_decryption,
@@ -661,16 +666,18 @@ mod tests {
                 0x74, 0x20, 0x65, 0x6e, 0x6f, 0x75, 0x67, 0x68
             ])
         );
-        assert!(Memo::from_str(
-            "thiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiis \
-             iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiis \
-             aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa \
-             veeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeryyyyyyyyyyyyyyyyyyyyyyyyyy \
-             looooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong \
-             meeeeeeeeeeeeeeeeeeemooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo \
-             but it's now a bit too long"
-        )
-        .is_none());
+        assert_eq!(
+            Memo::from_str(
+                "thiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiis \
+                 iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiis \
+                 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa \
+                 veeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeryyyyyyyyyyyyyyyyyyyyyyyyyy \
+                 looooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong \
+                 meeeeeeeeeeeeeeeeeeemooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo \
+                 but it's now a bit too long"
+            ),
+            Err(())
+        );
     }
 
     #[test]