Should we have different withdraw functions for the recipient and the sender

[andreivladbrg]

As I've mentioned in this discussion:

I realized that if we have separate functions for the sender and for the recipient (implicitly for approved operators) in core, it would allow the recipients to use ERC721.approve and let the sender withdraw to any address for them.

At the moment if the sender is an approved operator it would still revert because the check is made in the same function:

v2-core/src/abstracts/SablierV2Lockup.sol

Lines 251 to 262 in 91887da

	// Checks: `msg.sender` is the stream's sender, the stream's recipient, or an approved third party.
	if (!isCallerStreamSender && !_isCallerStreamRecipientOrApproved(streamId)) {
	revert Errors.SablierV2Lockup_Unauthorized(streamId, msg.sender);
	}
	// Retrieve the recipient from storage.
	address recipient = _ownerOf(streamId);
	// Checks: if `msg.sender` is the stream's sender, the withdrawal address must be the recipient.
	if (isCallerStreamSender && to != recipient) {
	revert Errors.SablierV2Lockup_InvalidSenderWithdrawal(streamId, msg.sender, to);
	}

What do you think? Should we have separate functions for withdraw? @PaulRBerg @razgraf

[PaulRBerg]

I am against introducing a mirror function just for the sake of this little functionality.

I suggest we ignore this feature and continue with building a global set of Sablier rescuers.