fix(trie): pass down hash function for hashing on trie copies

[faustbrian]

Resolves #2067 (comment) via #2067 (comment)
Needed for #2067 to write proper tests

Something I noticed here https://github.com/ethereumjs/ethereumjs-monorepo/blob/master/packages/trie/src/trie/secure.ts#L109 is that hash: this.hash seems to be missing. The Trie passes it down when it calls copy but CheckpointTrie and SecureTrie don't. Is this intentional or an oversight?

  copy(): Trie {
    return new Trie({
      db: this.db.copy(),
      root: this.root,
      deleteFromDB: this._deleteFromDB,
      hash: this._hash,
    })
  }

I assume this could result in corrupted data if you copy a CheckpointTrie or SecureTrie that for example uses sha256 but then it doesn't pass down the hash function and the copy works with keccak256 hashes because const _hash = opts?.hash ?? keccak256 will fall back to the keccak256 function?

  it.test('created copy uses the correct hash function', async function (t) {
    const trie = new SecureTrie({
      db: new LevelDB(),
      hash: (value) => createHash('sha256').update(value).digest(),
    })

    await trie.put(Buffer.from('key1'), Buffer.from('value1'))
    trie.checkpoint()
    await trie.put(Buffer.from('key2'), Buffer.from('value2'))
    const trieCopy = trie.copy()
    const value = await trieCopy.get(Buffer.from('key1'))
    t.equal(value!.toString(), 'value1')
    t.end()
  })

# created copy uses the correct hash function

not ok 183 TypeError: Cannot read properties of null (reading 'toString')
  ---
    operator: error
    stack: |-
      TypeError: Cannot read properties of null (reading 'toString')
          at Test.<anonymous> (/Users/brianfaust/Work/bearmint/ethereumjs-monorepo/packages/trie/test/trie/secure.spec.ts:167:20)

I think the above reproduces the issue. If I then change to the following copy function for SecureTrie it'll pass.

  copy(includeCheckpoints = true): SecureTrie {
    const secureTrie = new SecureTrie({
      db: this.dbStorage.copy(),
      root: this.root,
      deleteFromDB: (this as any)._deleteFromDB,
      hash: this._hash,
    })
    if (includeCheckpoints && this.isCheckpoint) {
      secureTrie.db.checkpoints = [...this.db.checkpoints]
    }
    return secureTrie
  }

The above test will fail because it will store key1 hashed via sha256 and key2 hashed via keccak256 but then the copy of the trie will use keccak256 again because this.hash wasn't passed down which results in it looking up key1 hashed via keccak256 instead of the sha256 it was stored as.

[codecov]

Codecov Report

Merging #2068 (1648b41) into master (d276fcc) will increase coverage by 0.00%.
The diff coverage is 100.00%.

Flag	Coverage Δ
block	83.75% <ø> (ø)
blockchain	80.10% <ø> (ø)
client	78.37% <ø> (ø)
common	95.00% <ø> (ø)
devp2p	82.73% <ø> (+0.06%)	⬆️
ethash	90.81% <ø> (ø)
evm	40.89% <ø> (ø)
statemanager	84.55% <ø> (ø)
trie	80.82% <100.00%> (-0.03%)	⬇️
tx	92.18% <ø> (ø)
util	87.22% <ø> (ø)
vm	78.51% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

[acolytec3]

LGTM