chore: improve into_merge_value fn

Author: Code Monad

src/merge.rs

@@ -80,8 +80,8 @@ impl MergeValue {
 #[cfg(feature = "trie")]
 pub fn into_merge_value<H: Hasher + Default>(key: H256, value: H256, height: u8) -> MergeValue {
     // try keep hash same with MergeWithZero
-    if value.is_zero() {
-        MergeValue::from_h256(H256::zero())
+    if value.is_zero() || height == 0 {
+        MergeValue::from_h256(value)
     } else {
         let base_key = key.parent_path(0);
         let base_node = hash_base_node::<H>(0, &base_key, &value);

src/trie_tree.rs

@@ -367,15 +367,11 @@ impl<H: Hasher + Default, V: Value, S: StoreReadOps<V>> SparseMerkleTree<H, V, S
                                 if leaves_bitmap[leaf_index].get_bit(fork_height)
                                     && heights.contains(&fork_height)
                                 {
-                                    if fork_height == 0 {
-                                        proof_result.push(MergeValue::from_h256(value))
-                                    } else {
-                                        proof_result.push(into_merge_value::<H>(
-                                            key,
-                                            value,
-                                            fork_height,
-                                        ))
-                                    }
+                                    proof_result.push(into_merge_value::<H>(
+                                        key,
+                                        value,
+                                        fork_height,
+                                    ))
                                 }
                             }
                             break;