Challenge 18

tx.origin Misuse

MediumStorage and memory

Challenge

Review activateUser. Does changing the local User value update the mapping entry?

Starter code

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

contract StorageBug {
  struct User {
    uint256 balance;
    bool isActive;
  }

  mapping(address => User) public users;

  function activateUser() public {
    User memory user = users[msg.sender];
    user.isActive = true;
  }

  function deposit() public payable {
    users[msg.sender].balance += msg.value;
  }
}

Show hint

A memory copy is separate from the mapping's stored struct. Update the storage entry itself.