fix(Multicall): use correct assembly for revert bubbling #98
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Related Issue
N/A
Description of changes
The implementation taken from stackoverflow uses incorrect assembly.
Since the first 32 bytes of
bytes memory resultwill be the length as uint256, only adding 4 to the pointer makes theError(string)signature (0x6408c379a0) as the length, which is incorrect. See tests hereThis medium article by @0xdeadbeef0x goes over the possible things that can go wrong with this exact implementation:
https://medium.com/@0xdeadbeef0x/the-double-edged-sword-of-abi-decode-f81529e62bcc
Therefore the correct way is to add 32 and revert the data with the length specified.
Also this solution works for both string style (
revert("reason"),require(false, "reason")) and custom error stylerevert CustomError(), making the code cleaner.