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

a6efe98 Use write_all to write whole buffer (Tobin C. Harding)
51c60b8 Allow no is_empty method for VarInt (Tobin C. Harding)
841f1f5 Implement Default for TaprootBuilder (Tobin C. Harding)
f81d4aa Remove unnecessary call to clone (Tobin C. Harding)
27649ba Use copied instead of map to copy (Tobin C. Harding)
62ccc91 Use iter().flatten().any() instead of if let Some (Tobin C. Harding)
4b28a1b Remove unneeded return statement (Tobin C. Harding)
16cac3c Derive Default for Witness (Tobin C. Harding)
c751898 Remove unnecessary closure (Tobin C. Harding)
dfff853 Ignore bytes written for sighash_single bug output (Tobin C. Harding)
14c72e7 Use contains combinator instead of manual range (Tobin C. Harding)
b7d6c3e Remove additional reference (Tobin C. Harding)
1940b00 Implement From instead of Into (Tobin C. Harding)
fcd0f4d Use struct field init shorthand (Tobin C. Harding)
641960f Use rustfmt::skip (Tobin C. Harding)
3cd00e5 Remove unnecessary whitespace (Tobin C. Harding)

Pull request description:

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

  - [commit](rust-bitcoin/rust-bitcoin@fcd0f4d): `fcd0f4d Use struct field init shorthand`
  - [commit](rust-bitcoin/rust-bitcoin@14c72e7): `14c72e7 Use contains combinator instead of manual range`
  - [commit](rust-bitcoin/rust-bitcoin@3b3c378): `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 a6efe98
  Kixunil:
    ACK a6efe98

Tree-SHA512: 5351a82fd3deadb8e53911c43b5a60a9517d5c57014f5fa833b79b32c0a4606ada0bcd28e06ce35d47aa74115c7cf70c27a1ba9c561a3424ac85a4f69774014d

Author: apoelstra

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 {