trie panics with cannot convert a slice of length 29 to FixedBytes<32> with small data #9
Description
I am trying to replace triehash::ordered_trie_root with an equivalent function based on alloy-trie. Even if it works pretty well, sometimes alloy-trie panics with a cannot convert a slice of length 29 to FixedBytes<32> error. Here is a complete reproducer for the issue:
use std::collections::BTreeMap;
use alloy_primitives::{keccak256, B256};
use alloy_rlp::Encodable;
use alloy_trie::HashBuilder;
use nybbles::Nibbles;
fn triehash_ordered_trie_root<I>(iter: I) -> B256
where
I: IntoIterator,
I::Item: AsRef<[u8]>,
{
struct Keccak256Hasher;
impl hash_db::Hasher for Keccak256Hasher {
type Out = B256;
type StdHasher = plain_hasher::PlainHasher;
const LENGTH: usize = 32;
fn hash(x: &[u8]) -> Self::Out {
keccak256(x)
}
}
triehash::ordered_trie_root::<Keccak256Hasher, _>(iter)
}
fn alloy_ordered_trie_root<I>(iter: I) -> B256
where
I: IntoIterator,
I::Item: AsRef<[u8]>,
{
let hashed = iter
.into_iter()
.enumerate()
.map(|(i, v)| {
let mut buf = Vec::new();
i.encode(&mut buf);
(buf, v)
})
.collect::<BTreeMap<_, _>>();
let mut hb = HashBuilder::default();
hashed.iter().for_each(|(key, val)| {
let nibbles = Nibbles::unpack(key);
hb.add_leaf(nibbles, val.as_ref());
});
hb.root()
}
// This fails with error:
// cannot convert a slice of length 29 to FixedBytes<32>
#[test]
fn small_data() {
let data = &["cake", "pie", "candy"];
assert_eq!(triehash_ordered_trie_root(data), alloy_ordered_trie_root(data));
}
// This succeeds.
#[test]
fn big_data() {
let data = &["a_very_big_cake", "a_very_big_pie", "a_lots_of_candies"];
assert_eq!(triehash_ordered_trie_root(data), alloy_ordered_trie_root(data));
}