Merge rust-bitcoin/rust-bitcoin#1004: Clear Clippy warnings

a6efe982bd Use write_all to write whole buffer (Tobin C. Harding)
51c60b8507 Allow no is_empty method for VarInt (Tobin C. Harding)
841f1f5832 Implement Default for TaprootBuilder (Tobin C. Harding)
f81d4aa9bd Remove unnecessary call to clone (Tobin C. Harding)
27649ba182 Use copied instead of map to copy (Tobin C. Harding)
62ccc9102c Use iter().flatten().any() instead of if let Some (Tobin C. Harding)
4b28a1bb97 Remove unneeded return statement (Tobin C. Harding)
16cac3cd70 Derive Default for Witness (Tobin C. Harding)
c75189841a Remove unnecessary closure (Tobin C. Harding)
dfff85352a Ignore bytes written for sighash_single bug output (Tobin C. Harding)
14c72e755b Use contains combinator instead of manual range (Tobin C. Harding)
b7d6c3e02c Remove additional reference (Tobin C. Harding)
1940b00132 Implement From instead of Into (Tobin C. Harding)
fcd0f4deac Use struct field init shorthand (Tobin C. Harding)
641960f037 Use rustfmt::skip (Tobin C. Harding)
3cd00e5d47 Remove unnecessary whitespace (Tobin C. Harding)

Pull request description:

  Clear all current Clippy warnings, codebase wide. Possibly contentious patches include:

  - [commit](fcd0f4deac): `fcd0f4d Use struct field init shorthand`
  - [commit](14c72e755b): `14c72e7 Use contains combinator instead of manual range`
  - [commit](3b3c37803a): `3b3c378 Use iter().flatten() instead of if let Some`

  ## Notes

  Please note commit `dfff8535 Ignore bytes written for sighash_single bug output` touches the same lines of code as commit `a6efe982 Use write_all to write whole buffer`.

ACKs for top commit:
  apoelstra:
    ACK a6efe982bd
  Kixunil:
    ACK a6efe982bd

Tree-SHA512: 5351a82fd3deadb8e53911c43b5a60a9517d5c57014f5fa833b79b32c0a4606ada0bcd28e06ce35d47aa74115c7cf70c27a1ba9c561a3424ac85a4f69774014d

src/blockdata/script.rs

@@ -470,9 +470,9 @@ impl Script {
     /// the current script, assuming that the script is a Tapscript.
     #[inline]
     pub fn to_v1_p2tr<C: Verification>(&self, secp: &Secp256k1<C>, internal_key: UntweakedPublicKey) -> Script {
-        let leaf_hash = TapLeafHash::from_script(&self, LeafVersion::TapScript);
+        let leaf_hash = TapLeafHash::from_script(self, LeafVersion::TapScript);
         let merkle_root = TapBranchHash::from_inner(leaf_hash.into_inner());
-        Script::new_v1_p2tr(&secp, internal_key, Some(merkle_root))
+        Script::new_v1_p2tr(secp, internal_key, Some(merkle_root))
     }
 
     /// Returns witness version of the script, if any, assuming the script is a `scriptPubkey`.
@@ -525,7 +525,7 @@ impl Script {
         // special meaning. The value of the first push is called the "version byte". The following
         // byte vector pushed is called the "witness program".
         let script_len = self.0.len();
-        if script_len < 4 || script_len > 42 {
+        if !(4..=42).contains(&script_len) {
             return false
         }
         let ver_opcode = opcodes::All::from(self.0[0]); // Version 0 or PUSHNUM_1-PUSHNUM_16
@@ -877,7 +877,7 @@ impl Builder {
     /// dedicated opcodes to push some small integers.
     pub fn push_int(self, data: i64) -> Builder {
         // We can special-case -1, 1-16
-        if data == -1 || (data >= 1 && data <= 16) {
+        if data == -1 || (1..=16).contains(&data) {
             let opcode = opcodes::All::from(
                 (data - 1 + opcodes::OP_TRUE.into_u8() as i64) as u8
             );

src/blockdata/transaction.rs

@@ -353,7 +353,7 @@ impl Transaction {
             // will result in the data written to the writer being hashed, however the correct
             // handling of the SIGHASH_SINGLE bug is to return the 'one array' - either implement
             // this behaviour manually or use `signature_hash()`.
-            writer.write(b"[not a transaction] SIGHASH_SINGLE bug")?;
+            writer.write_all(b"[not a transaction] SIGHASH_SINGLE bug")?;
             return Ok(())
         }
 

src/blockdata/witness.rs

@@ -22,7 +22,7 @@ use serde;
 /// For serialization and deserialization performance it is stored internally as a single `Vec`,
 /// saving some allocations.
 ///
-#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Debug, Hash)]
+#[derive(Clone, Default, PartialEq, Eq, PartialOrd, Ord, Debug, Hash)]
 pub struct Witness {
     /// contains the witness Vec<Vec<u8>> serialization without the initial varint indicating the
     /// number of elements (which is stored in `witness_elements`)
@@ -67,12 +67,12 @@ impl Decodable for Witness {
                 let element_size = element_size_varint.0 as usize;
                 let required_len = cursor
                     .checked_add(element_size)
-                    .ok_or_else(|| self::Error::OversizedVectorAllocation {
+                    .ok_or(self::Error::OversizedVectorAllocation {
                         requested: usize::max_value(),
                         max: MAX_VEC_SIZE,
                     })?
                     .checked_add(element_size_varint_len)
-                    .ok_or_else(|| self::Error::OversizedVectorAllocation {
+                    .ok_or(self::Error::OversizedVectorAllocation {
                         requested: usize::max_value(),
                         max: MAX_VEC_SIZE,
                     })?;
@@ -218,7 +218,7 @@ impl Witness {
     pub fn push_bitcoin_signature(&mut self, signature: &ecdsa::SerializedSignature, hash_type: EcdsaSighashType) {
         // Note that a maximal length ECDSA signature is 72 bytes, plus the sighash type makes 73
         let mut sig = [0; 73];
-        sig[..signature.len()].copy_from_slice(&signature);
+        sig[..signature.len()].copy_from_slice(signature);
         sig[signature.len()] = hash_type as u8;
         self.push(&sig[..signature.len() + 1]);
     }
@@ -249,19 +249,6 @@ impl Witness {
     }
 }
 
-impl Default for Witness {
-    fn default() -> Self {
-        // from https://doc.rust-lang.org/std/vec/struct.Vec.html#method.new
-        // The vector will not allocate until elements are pushed onto it.
-        Witness {
-            content: Vec::new(),
-            witness_elements: 0,
-            last: 0,
-            second_to_last: 0,
-        }
-    }
-}
-
 impl<'a> Iterator for Iter<'a> {
     type Item = &'a [u8];
 

src/consensus/encode.rs

@@ -400,6 +400,7 @@ impl_int_encodable!(i16, read_i16, emit_i16);
 impl_int_encodable!(i32, read_i32, emit_i32);
 impl_int_encodable!(i64, read_i64, emit_i64);
 
+#[allow(clippy::len_without_is_empty)] // VarInt has on concept of 'is_empty'.
 impl VarInt {
     /// Gets the length of this VarInt when encoded.
     /// Returns 1 for 0..=0xFC, 3 for 0xFD..=(2^16-1), 5 for 0x10000..=(2^32-1),

src/network/constants.rs

@@ -238,9 +238,9 @@ impl From<u64> for ServiceFlags {
     }
 }
 
-impl Into<u64> for ServiceFlags {
-    fn into(self) -> u64 {
-        self.0
+impl From<ServiceFlags> for u64 {
+    fn from(flags: ServiceFlags) -> Self {
+        flags.0
     }
 }
 

src/util/address.rs

@@ -621,7 +621,7 @@ impl Address {
         network: Network
     ) -> Address {
         Address {
-            network: network,
+            network,
             payload: Payload::p2tr(secp, internal_key, merkle_root),
         }
     }

src/util/bip32.rs

@@ -283,9 +283,9 @@ impl From<Vec<ChildNumber>> for DerivationPath {
     }
 }
 
-impl Into<Vec<ChildNumber>> for DerivationPath {
-    fn into(self) -> Vec<ChildNumber> {
-        self.0
+impl From<DerivationPath> for Vec<ChildNumber> {
+    fn from(path: DerivationPath) -> Self {
+        path.0
     }
 }
 

src/util/ecdsa.rs

@@ -58,7 +58,7 @@ impl EcdsaSig {
     pub fn to_vec(&self) -> Vec<u8> {
         // TODO: add support to serialize to a writer to SerializedSig
         self.sig.serialize_der()
-            .iter().map(|x| *x)
+            .iter().copied()
             .chain(iter::once(self.hash_ty as u8))
             .collect()
     }

src/util/key.rs

@@ -228,7 +228,7 @@ impl FromStr for PublicKey {
         match s.len() {
             66 => PublicKey::from_slice(&<[u8; 33]>::from_hex(s)?),
             130 => PublicKey::from_slice(&<[u8; 65]>::from_hex(s)?),
-            len => return Err(Error::Hex(hex::Error::InvalidLength(66, len)))
+            len => Err(Error::Hex(hex::Error::InvalidLength(66, len))),
         }
     }
 }

src/util/psbt/macros.rs

@@ -92,7 +92,7 @@ macro_rules! impl_psbtmap_consensus_enc_dec_oding {
     };
 }
 
-#[cfg_attr(rustfmt, rustfmt_skip)]
+#[rustfmt::skip]
 macro_rules! impl_psbt_insert_pair {
     ($slf:ident.$unkeyed_name:ident <= <$raw_key:ident: _>|<$raw_value:ident: $unkeyed_value_type:ty>) => {
         if $raw_key.key.is_empty() {
@@ -122,8 +122,7 @@ macro_rules! impl_psbt_insert_pair {
     };
 }
 
-
-#[cfg_attr(rustfmt, rustfmt_skip)]
+#[rustfmt::skip]
 macro_rules! impl_psbt_get_pair {
     ($rv:ident.push($slf:ident.$unkeyed_name:ident, $unkeyed_typeval:ident)) => {
         if let Some(ref $unkeyed_name) = $slf.$unkeyed_name {

src/util/psbt/serialize.rs

@@ -125,7 +125,7 @@ impl Deserialize for EcdsaSig {
         // also has a field sighash_u32 (See BIP141). For example, when signing with non-standard
         // 0x05, the sighash message would have the last field as 0x05u32 while, the verification
         // would use check the signature assuming sighash_u32 as `0x01`.
-        EcdsaSig::from_slice(&bytes)
+        EcdsaSig::from_slice(bytes)
             .map_err(|e| match e {
                 EcdsaSigError::EmptySignature => {
                     encode::Error::ParseFailed("Empty partial signature data")
@@ -145,7 +145,7 @@ impl Deserialize for EcdsaSig {
 
 impl Serialize for KeySource {
     fn serialize(&self) -> Vec<u8> {
-        let mut rv: Vec<u8> = Vec::with_capacity(key_source_len(&self));
+        let mut rv: Vec<u8> = Vec::with_capacity(key_source_len(self));
 
         rv.append(&mut self.0.to_bytes().to_vec());
 
@@ -207,7 +207,7 @@ impl Deserialize for PsbtSighashType {
 // Taproot related ser/deser
 impl Serialize for XOnlyPublicKey {
     fn serialize(&self) -> Vec<u8> {
-        XOnlyPublicKey::serialize(&self).to_vec()
+        XOnlyPublicKey::serialize(self).to_vec()
     }
 }
 
@@ -226,7 +226,7 @@ impl Serialize for schnorr::SchnorrSig  {
 
 impl Deserialize for schnorr::SchnorrSig {
     fn deserialize(bytes: &[u8]) -> Result<Self, encode::Error> {
-        schnorr::SchnorrSig::from_slice(&bytes)
+        schnorr::SchnorrSig::from_slice(bytes)
             .map_err(|e| match e {
                 schnorr::SchnorrSigError::InvalidSighashType(flag) => {
                     encode::Error::from(psbt::Error::NonStandardSighashType(flag as u32))
@@ -264,7 +264,7 @@ impl Deserialize for (XOnlyPublicKey, TapLeafHash) {
 
 impl Serialize for ControlBlock {
     fn serialize(&self) -> Vec<u8> {
-        ControlBlock::serialize(&self)
+        ControlBlock::serialize(self)
     }
 }
 
@@ -311,7 +311,7 @@ impl Serialize for (Vec<TapLeafHash>, KeySource) {
 
 impl Deserialize for (Vec<TapLeafHash>, KeySource) {
     fn deserialize(bytes: &[u8]) -> Result<Self, encode::Error> {
-        let (leafhash_vec, consumed) = deserialize_partial::<Vec<TapLeafHash>>(&bytes)?;
+        let (leafhash_vec, consumed) = deserialize_partial::<Vec<TapLeafHash>>(bytes)?;
         let key_source = KeySource::deserialize(&bytes[consumed..])?;
         Ok((leafhash_vec, key_source))
     }

src/util/schnorr.rs

@@ -109,10 +109,10 @@ impl TapTweak for UntweakedPublicKey {
     /// The tweaked key and its parity.
     fn tap_tweak<C: Verification>(self, secp: &Secp256k1<C>, merkle_root: Option<TapBranchHash>) -> (TweakedPublicKey, secp256k1::Parity) {
         let tweak_value = TapTweakHash::from_key_and_tweak(self, merkle_root).into_inner();
-        let mut output_key = self.clone();
-        let parity = output_key.tweak_add_assign(&secp, &tweak_value).expect("Tap tweak failed");
+        let mut output_key = self;
+        let parity = output_key.tweak_add_assign(secp, &tweak_value).expect("Tap tweak failed");
 
-        debug_assert!(self.tweak_add_check(&secp, &output_key, parity, tweak_value));
+        debug_assert!(self.tweak_add_check(secp, &output_key, parity, tweak_value));
         (TweakedPublicKey(output_key), parity)
     }
 
@@ -140,7 +140,7 @@ impl TapTweak for UntweakedKeyPair {
     fn tap_tweak<C: Verification>(mut self, secp: &Secp256k1<C>, merkle_root: Option<TapBranchHash>) -> TweakedKeyPair {
         let pubkey = crate::XOnlyPublicKey::from_keypair(&self);
         let tweak_value = TapTweakHash::from_key_and_tweak(pubkey, merkle_root).into_inner();
-        self.tweak_add_assign(&secp, &tweak_value).expect("Tap tweak failed");
+        self.tweak_add_assign(secp, &tweak_value).expect("Tap tweak failed");
         TweakedKeyPair(self)
     }
 
@@ -229,7 +229,7 @@ impl SchnorrSig {
                 // default type
                 let sig = secp256k1::schnorr::Signature::from_slice(sl)
                     .map_err(SchnorrSigError::Secp256k1)?;
-                return Ok( SchnorrSig { sig, hash_ty : SchnorrSighashType::Default });
+                Ok(SchnorrSig { sig, hash_ty: SchnorrSighashType::Default })
             },
             65 => {
                 let (hash_ty, sig) = sl.split_last().expect("Slice len checked == 65");

src/util/sighash.rs

@@ -440,7 +440,7 @@ impl<R: Deref<Target = Transaction>> SighashCache<R> {
                     .tx
                     .input
                     .get(input_index)
-                    .ok_or_else(|| Error::IndexOutOfInputsBounds {
+                    .ok_or(Error::IndexOutOfInputsBounds {
                         index: input_index,
                         inputs_size: self.tx.input.len(),
                     })?;
@@ -473,7 +473,7 @@ impl<R: Deref<Target = Transaction>> SighashCache<R> {
             self.tx
                 .output
                 .get(input_index)
-                .ok_or_else(|| Error::SingleWithoutCorrespondingOutput {
+                .ok_or(Error::SingleWithoutCorrespondingOutput {
                     index: input_index,
                     outputs_size: self.tx.output.len(),
                 })?
@@ -597,7 +597,7 @@ impl<R: Deref<Target = Transaction>> SighashCache<R> {
                     .tx
                     .input
                     .get(input_index)
-                    .ok_or_else(|| Error::IndexOutOfInputsBounds {
+                    .ok_or(Error::IndexOutOfInputsBounds {
                         index: input_index,
                         inputs_size: self.tx.input.len(),
                     })?;

src/util/taproot.rs

@@ -217,10 +217,10 @@ impl TaprootSpendInfo {
     ) -> Self {
         let (output_key, parity) = internal_key.tap_tweak(secp, merkle_root);
         Self {
-            internal_key: internal_key,
-            merkle_root: merkle_root,
+            internal_key,
+            merkle_root,
             output_key_parity: parity,
-            output_key: output_key,
+            output_key,
             script_map: BTreeMap::new(),
         }
     }
@@ -442,14 +442,7 @@ impl TaprootBuilder {
 
     /// Checks if the builder has hidden nodes.
     pub fn has_hidden_nodes(&self) -> bool {
-        for node in &self.branch {
-            if let Some(node) = node {
-                if node.has_hidden_nodes {
-                    return true
-                }
-            }
-        }
-        false
+        self.branch.iter().flatten().any(|node| node.has_hidden_nodes)
     }
 
     /// Creates a [`TaprootSpendInfo`] with the given internal key.
@@ -521,6 +514,12 @@ impl TaprootBuilder {
     }
 }
 
+impl Default for TaprootBuilder {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 /// Represents the node information in taproot tree.
 ///
 /// Helper type used in merkle tree construction allowing one to build sparse merkle trees. The node
@@ -544,7 +543,7 @@ impl NodeInfo {
     /// Creates a new [`NodeInfo`] with omitted/hidden info.
     pub fn new_hidden_node(hash: sha256::Hash) -> Self {
         Self {
-            hash: hash,
+            hash,
             leaves: vec![],
             has_hidden_nodes: true
         }
@@ -596,8 +595,8 @@ impl ScriptLeaf {
     /// Creates an new [`ScriptLeaf`] from `script` and `ver` and no merkle branch.
     fn new(script: Script, ver: LeafVersion) -> Self {
         Self {
-            script: script,
-            ver: ver,
+            script,
+            ver,
             merkle_branch: TaprootMerkleBranch(vec![]),
         }
     }
@@ -682,7 +681,7 @@ impl TaprootMerkleBranch {
 
     /// Serializes `self` as bytes.
     pub fn serialize(&self) -> Vec<u8> {
-        self.0.iter().map(|e| e.as_inner()).flatten().map(|x| *x).collect::<Vec<u8>>()
+        self.0.iter().flat_map(|e| e.as_inner()).copied().collect::<Vec<u8>>()
     }
 
     /// Appends elements to proof.
@@ -802,7 +801,7 @@ impl ControlBlock {
     ) -> bool {
         // compute the script hash
         // Initially the curr_hash is the leaf hash
-        let leaf_hash = TapLeafHash::from_script(&script, self.leaf_version);
+        let leaf_hash = TapLeafHash::from_script(script, self.leaf_version);
         let mut curr_hash = TapBranchHash::from_inner(leaf_hash.into_inner());
         // Verify the proof
         for elem in self.merkle_branch.as_inner() {