Merge rust-bitcoin/rust-bitcoin#3400: Move `merkle_tree` hash types to `primitives`

9ded58fc99 Move merkle_tree hash types to primitives (Tobin C. Harding)

Pull request description:

  In preparation for moving the `block::Header` struct over to `primitives` move the `merkle_tree` hash types.

ACKs for top commit:
  apoelstra:
    ACK 9ded58fc99 successfully ran local tests

Tree-SHA512: 98017cf0403871f01a6efeda22e8f319cc8104b9bc2f3a9bae2d6a31f6df8172307466c6486a9259204166933137fa03e565e08a0c156c278cfeb72cdae09b89

bitcoin/src/merkle_tree/mod.rs

@@ -26,13 +26,8 @@ use crate::{Txid, Wtxid};
 #[rustfmt::skip]
 #[doc(inline)]
 pub use self::block::{MerkleBlock, MerkleBlockError, PartialMerkleTree};
+pub use primitives::merkle_tree::*;
 
-hashes::hash_newtype! {
-    /// A hash of the Merkle tree branch or root for transactions.
-    pub struct TxMerkleNode(sha256d::Hash);
-    /// A hash corresponding to the Merkle tree root for witness data.
-    pub struct WitnessMerkleNode(sha256d::Hash);
-}
 impl_hashencode!(TxMerkleNode);
 impl_hashencode!(WitnessMerkleNode);
 
@@ -104,7 +99,7 @@ impl MerkleNode for TxMerkleNode {
         let mut encoder = sha256d::Hash::engine();
         encoder.input(self.as_byte_array());
         encoder.input(other.as_byte_array());
-        Self(sha256d::Hash::from_engine(encoder))
+        Self::from_byte_array(sha256d::Hash::from_engine(encoder).to_byte_array())
     }
 }
 impl MerkleNode for WitnessMerkleNode {
@@ -115,7 +110,7 @@ impl MerkleNode for WitnessMerkleNode {
         let mut encoder = sha256d::Hash::engine();
         encoder.input(self.as_byte_array());
         encoder.input(other.as_byte_array());
-        Self(sha256d::Hash::from_engine(encoder))
+        Self::from_byte_array(sha256d::Hash::from_engine(encoder).to_byte_array())
     }
 }
 

primitives/src/lib.rs

@@ -32,6 +32,7 @@ extern crate serde;
 #[cfg(feature = "alloc")]
 pub mod locktime;
 pub mod opcodes;
+pub mod merkle_tree;
 pub mod pow;
 pub mod sequence;
 pub mod transaction;

primitives/src/merkle_tree.rs

@@ -0,0 +1,12 @@
+// SPDX-License-Identifier: CC0-1.0
+
+//! Bitcoin Merkle tree functions.
+
+use hashes::sha256d;
+
+hashes::hash_newtype! {
+    /// A hash of the Merkle tree branch or root for transactions.
+    pub struct TxMerkleNode(sha256d::Hash);
+    /// A hash corresponding to the Merkle tree root for witness data.
+    pub struct WitnessMerkleNode(sha256d::Hash);
+}