Cap lightning fees with maximum value, not merely percentage

[andronoob]

Might be dupelicate with #36.

A lot of LN nodes has a base routing fee, e.g. 1sat/payment. Therefore, if the user trys to pay an extreme small amount, currently the payment usually fail, due to the 3% limit. If the user simply turn off this limit, it seems that he's taking some risk of being accidentally charged with extreme high fees.

I think the fee capping policy should be more sophiscated, e.g. for payment smaller than 1000sat, cap the fee with a fixed 30sat limit.

[dpad85]

Hello,

This issue has been fixed with the v0.3.19 release, which is available on mainnet and testnet. If the fee is below 21 satoshi, the fee protection mechanism will not reject the payment.

You can take a look at @araspitzu PR for more information: ACINQ/eclair#844

[pm47]

So you have paid a 0.0072 USD fee, SFYL. This fee hasn't gone to us but to whoever has routed the payment.

The 3% limit is not a target fee but a protection. By the way there is a tolerance for small amounts so you may be paying more than >100% fees for 1 sat payments. How about that?

It's not easy to know beforehand what the fee will be, because most of the time we have to try several payment routes before finding one that works. UX would be terrible if we showed a popup ten times in a row. Trampoline will help but it will also have to be pessimistic with fee calculations.

Strong language, accusing us of ransoming users => blocked.