Reworking hash concatenation

crates/core/src/address/raw.rs

@@ -65,10 +65,10 @@ pub enum Discriminant {
     IbcToken = 13,
     /// MASP raw address.
     Masp = 14,
-    /// Replay protection
-    ReplayProtection = 15,
     /// Temporary storage address.
-    TempStorage = 16,
+    TempStorage = 15,
+    /// Replay protection
+    ReplayProtection = 16,
 }
 
 /// Raw address representation.

crates/core/src/hash.rs

@@ -1,7 +1,6 @@
 //! Types for working with 32 bytes hashes.
 
 use std::fmt::{self, Display};
-use std::ops::Add;
 use std::str::FromStr;
 
 use arse_merkle_tree::traits::Hasher;
@@ -155,12 +154,11 @@ impl Hash {
     pub const fn as_ptr(&self) -> *const u8 {
         self.0.as_ptr()
     }
-}
-
-impl<'a> Add<&'a Hash> for Hash {
-    type Output = Self;
 
-    fn add(self, rhs: &'a Hash) -> Self::Output {
+    /// Given hashes A and B, compute Sha256(A||B),
+    /// but if one value is the zero hash, the other
+    /// value is returned.
+    pub fn concat(self, rhs: &Hash) -> Self {
         let mut hasher = Sha256::default();
         if self.is_zero() {
             *rhs

crates/state/src/wl_state.rs

@@ -243,7 +243,7 @@ where
                         batch,
                         &replay_protection::current_key(hash),
                     )?;
-                    acc = acc + hash;
+                    acc = acc.concat(hash);
                     Ok::<_, Error>(acc)
                 })?;
         self.write(&replay_prot_key, new_commitment)?;