Fix for block 202612 and fix merkel root calculations

coins/monero/Cargo.toml

@@ -46,6 +46,7 @@ monero-generators = { path = "generators", version = "0.3", default-features = f
 
 futures = { version = "0.3", default-features = false, features = ["alloc"], optional = true }
 
+hex-literal = "0.4"
 hex = { version = "0.4", default-features = false, features = ["alloc"] }
 serde = { version = "1", default-features = false, features = ["derive"] }
 serde_json = { version = "1", default-features = false, features = ["alloc"] }
@@ -61,8 +62,6 @@ dalek-ff-group = { path = "../../crypto/dalek-ff-group", version = "0.3", defaul
 monero-generators = { path = "generators", version = "0.3", default-features = false }
 
 [dev-dependencies]
-hex-literal = "0.4"
-
 tokio = { version = "1", features = ["full"] }
 monero-rpc = "0.3"
 

coins/monero/src/block.rs

@@ -10,6 +10,11 @@ use crate::{
   transaction::{Input, Transaction},
 };
 
+const CORRECT_BLOCK_HASH_202612: [u8; 32] =
+  hex_literal::hex!("426d16cff04c71f8b16340b722dc4010a2dd3831c22041431f772547ba6e331a");
+const EXISTING_BLOCK_HASH_202612: [u8; 32] =
+  hex_literal::hex!("bbd604d2ba11ba27935e006ed39c9bfdd99b76bf4a50654bc1e1e61217962698");
+
 #[derive(Clone, PartialEq, Eq, Debug)]
 pub struct BlockHeader {
   pub major_version: u64,
@@ -87,10 +92,12 @@ impl Block {
   }
 
   pub fn hash(&self) -> [u8; 32] {
-    // TODO: Handle block 202612
-    // https://monero.stackexchange.com/questions/421/what-happened-at-block-202612
-    // If this block's header is fully-equivalent to 202612, return the malformed hash instead
-    hash(&self.serialize_hashable())
+    let hash = hash(&self.serialize_hashable());
+    if hash == CORRECT_BLOCK_HASH_202612 {
+      return EXISTING_BLOCK_HASH_202612;
+    };
+
+    hash
   }
 
   pub fn serialize(&self) -> Vec<u8> {

coins/monero/src/merkle.rs

@@ -39,7 +39,7 @@ pub fn merkle_root(root: [u8; 32], leafs: &[[u8; 32]]) -> [u8; 32] {
 
       // Do a traditional pairing off
       let mut new_hashes = Vec::with_capacity(hashes.len() / 2);
-      while hashes.len() > 2 {
+      while hashes.len() > 1 {
         let mut i = 0;
         while i < hashes.len() {
           new_hashes.push(hash(&[hashes[i], hashes[i + 1]].concat()));