How a contract burn another contract's NFT?

Question

in the WolfGame V2, their new contract WoolfReborn.sol(https://etherscan.deth.net/address/0x7f36182dee28c45de6072a34d29855bae76dbe2f) can burn NFT from old contract Woolf.sol(https://etherscan.deth.net/address/0xeb834ae72b30866af20a6ce5440fa598bfad3a42)

by use the function

function _attemptBurn(address owner, uint256 tokenId) internal 
{
    woolf.transferFrom(owner, address(0xdead), tokenId);
} 

how did they do that? in Woolf the transferFrom is

 function transferFrom(
    address from,
    address to,
    uint256 tokenId
  ) public virtual override {
    // Hardcode the Barn's approval so that users don't have to waste gas approving
    if (_msgSender() != address(barn))
      require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");
    _transfer(from, to, tokenId);
  }

It require _msgSender() is approved or owner, but the new contract is not the owner of the NFT, and there is no code to let the new contract get approved

Answer 1

They are actually checking if the msg.sender is the owner before minting it.

   /**
   * creates identical tokens in the new contract
   * and burns any original tokens that are not in the barn
   * @param tokenIds the ids of the tokens to migrate
   */
  function migrate(uint256[] calldata tokenIds) external whenNotPaused {
    for (uint i = 0; i < tokenIds.length; i++) {
      (address owner, bool inBarn) = _ownerOf(tokenIds[i]);
      require(owner == _msgSender(), "STOP! THIEF!");
      if (!inBarn) _attemptBurn(_msgSender(), tokenIds[i]);
      _mint(_msgSender(), tokenIds[i]); // built-in duplicate protection
    }
  }

Answer 2

If your new contracts get the approve the NFT permission then will be resolve the your issue.

Try this:

function migrate(uint256[] calldata tokenIds) external whenNotPaused {
    for (uint i = 0; i < tokenIds.length; i++) {
      (address owner, bool inBarn) = _ownerOf(tokenIds[i]);
      require(owner == _msgSender(), "STOP! THIEF!");

      if (!inBarn) {
         woolf._approve(address(this),tokenId);   // approve the tokenIDs Wise
        _attemptBurn(_msgSender(), tokenIds[i]);
      }

      _mint(_msgSender(), tokenIds[i]); // built-in duplicate protection
    }
  }