Check for root in EncodeAndHash

[kishansagathiya]

Issue summary

• Looking at the comments and code, trie.Hash() and trie.root.EncodeAndHash() should produce the same hash, but they don't. condition of len(key) < 32 is not checked in trie.Hash and it hashes everything, because in case of root nodes we are supposed to return hash of encoding as hash regardless of length of encoding. This creates mismatching hashes from both functions.

• Right now the logic used in node.EncodeAndHash() is repeating in trie.Hash.

• trie.Hash should get hash from trie.RootNode.EncodeAndHash() and return it

• In node.EncodeAndHash we should check if this node is root or not. If the node is root we should return blake2b hash of its encoding regardless of length of its encoding.

• And then, trie.Hash should get hash from trie.RootNode.EncodeAndHash() and return it.

Other information and links

[noot]

the root node should always be hashed when getting the trie hash, so I think the functionality of trie.Hash is correct. EncodeAndHash is for nodes that are not necessarily the root so it's not subject to the same rule

[kishansagathiya]

the root node should always be hashed when getting the trie hash, so I think the functionality of trie.Hash is correct. EncodeAndHash is for nodes that are not necessarily the root so it's not subject to the same rule

Ah, right. My bad!

I feel like we should check for root in EncodeAndHash and hash it. That should fix many problems. If we don't do this, we will have to do this separately every time we using EncodeAndHash.

[kishansagathiya]

closed in #2359