Event decoding for unnamed parameters is wrong

[vkgnosis]

A solidity event like

event MyEvent(uint8, uint16, uint32, uint64, uint128);

is compiled into an artifact that has a list with these parameters with each one having an empty "" name. In ethabi's event decoding code Event::parse_log parameters are stored in a hash map of event name to token. This leads to every parameter using a clone of the same Token. In this particular case it can cause for example the uint8 to have a value that is larger than 255 because it uses the same token as the uint128.

[mattsse]

This line will cause the problem for indexed event parameters. Also this chains (topics_named_tokens.chain(data_named_tokens)) first named and then data tokens, which caused issues when I implemented some derive macros, in ethers-rs, what I did instead was:
filter the params in indexed and not indexed, then decode the all, but then put them in the correct order. The way this can work is:

let mut tokens = Vec::with_capacity(topic_tokens.len() + data_tokens.len());
for input in &event.inputs {
  if input.indexed {
      tokens.push(topic_tokens.remove(0));
 } else {
      tokens.push(data_tokens.remove(0));
 }
}

I could fix this by copying this to Event::parse_log

[gakonst]

@vkgnosis @nlordell are there any plans on fixing this? we hit that in Foundry as seen above recently

[vkgnosis]

I don't remember the details of this after I reported it a year ago. We'd surely accept a PR that fixed this but no one is actively working on it.