Walletwasabi: Wrong Estimated Fee

[yahiheb]

Use TestNet but it happens on Main also

• Open Wasabi
• Go to Send tab

Estimated total fee is ~0.00000150 (Fee is 1)

• Select a coin & click the max button

now the Estimated total fee is ~0.00000143 (it should be ~0.00000110)

• Remove the Fee and set it again to 1

now it is correct ~0.00000110

[nopara73]

This can probably be improved, but even if it cannot, it's ok, because it's an estimation. So the todo here is to explore if it can be improved or not.

[MaxHillebrand]

I think this is working properly.
when you select more coins, the tx size and thus fee is higher, by 33 bytes per input - so I believe this is all OK?

[yahiheb]

I am selecting only 1 coin, and at first the estimation is 143 sat, if you delete the fee (1) and type it again the estimation is correct (110).
Btw even when the estimation is displayed 143 and you send the tx the fee is correct (110).

[nopara73]

You mean for same inputs, but writing it in another order generates different estimations? In that case it's a bug.

[yahiheb]

You mean for same inputs, but writing it in another order generates different estimations?

I don't understand.

[nopara73]

Do you get different estimation for the same data filled out, the only difference is just from what direction you're filling out the data?

[yahiheb]

I am on TestNet but that doesn't matter, the manual fee entry is on.

No coin is selected, the estimated total fees is ~0.00000150, the fee is 1 sat/vbyte
I have a 0.00018788 coin, I select it, the estimated total fees is now ~0.00000143
I click the Max button, the amount that is displayed (to be sent) is ~0.00018645
I delete the fee (1) and I type it again (1)
--> the amount changed to ~ 0.00018678 and the estimated total fees is now ~0.00000110

Note if you do not do the last step (delete the fee and type it again) and you send the transaction, the amount that is sent ~ 0.00018678 and the estimated fee is ~0.00000110 which are both correct.
The problem is only a display or update problem.

[nopara73]

I suspect this issue was introduced here: https://github.com/zkSNACKs/WalletWasabi/pull/2687

[nopara73]

There was an update problem introduced by that PR regarding fees. This one fixes it: https://github.com/zkSNACKs/WalletWasabi/pull/2842