Geth-statediff doesn't save storage if value is empty

[ramilexe]

System information

Geth
Version: 1.10.1-statediff-0.0.15
Git Commit: daa2cdd
Git Commit Date: 20210313
Architecture: amd64
Go Version: go1.15.5
Operating System: linux

Expected behaviour

In storage_cids table should be row with non-empty storage_leaf_key and mhKey should point to block table with RLP encoded empty string

Actual behaviour

In storage_cids table there is a row with empty storage_leaf_key and mhKey points to block table with empty data field

Steps to reproduce the behaviour

• Run geth-statediff
• deploy smart contract https://github.com/vulcanize/eth-watcher-runner/blob/master/contracts/Test.sol
• call setMessage function and pass empty string as input

[ramilexe]

Here JSON-RPC request to verify against geth leveldb:

> curl -H "Content-Type: application/json" -X POST --data '{"jsonrpc":"2.0", "method": "eth_getStorageAt", "params": ["0xafD0849Ee466Ef3232896DB4D41871566Fc7d028", "0x0", "pending"], "id": 1}' localhost:8545

{"jsonrpc":"2.0","id":1,"result":"0x0000000000000000000000000000000000000000000000000000000000000000"}

Replace 0xafD0849Ee466Ef3232896DB4D41871566Fc7d028 with your address of deployed contract

[ramilexe]

Related to vulcanize/ipld-eth-indexer#72

[i-norden]

Per out conversation in slack: zeroed values aren't stored in the trie, the real issue is that we are not correctly signifying when a zero-value node at a specific leaf key is pruned away (due to not including the leaf_key for the removed node in the row representing it)

To fix we should include the leaf key in the removed-node-type entries. mhKey should still be empty since there is technically no node at that path that we should be referencing, we are just signifying that a node has been removed.

[i-norden]

We also need to a script to update the current entries in our db0

[i-norden]

Fixed in #58 , although I will open a separate issue to track the separate script for repairing the current db.

[i-norden]

Also of note, the fix is for both state and storage tries