Add with_weight extrinsic

[shawntabrizi]

This adds a new utility function with_weight that allows Root origin to override the weight of any function call.

[shawntabrizi]

Other functions similar to this emit an event with the result, swallow the result, and just return Ok(()). I think now that we have storage layer by default, we can simply return the result, which I have opted for here.

[MOZGIII]

Why add this if pallet_sudo with sudo_unchecked_weight exists?

[bkchr]

Why add this if pallet_sudo with sudo_unchecked_weight exists?

Because you don't have the sudo pallet on production networks after the initial phase.

[MOZGIII]

Should the sudo_unchecked_weight be removed from pallet_sudo then?
Also, the difference between them is that sudo has Pays::No. Was it lost here, or was it intentionally omitted?

[bkchr]

Should the sudo_unchecked_weight be removed from pallet_sudo then?

I can imagine runtimes where you only have sudo, but not pallet-utility. So, I would keep it.

Also, the difference between them is that sudo has Pays::No. Was it lost here, or was it intentionally omitted?

This call can never be called directly. It requires that you are root, which requires that you are either going through the sudo pallet or it is executed by the scheduler etc. None of these charge fees, so setting Pays::No would not change anything.

[MOZGIII]

I see. So, the sudo_unchecked_weight at pallet_sudo can also effectively omit the Pays::No, since it must be called from the sudo account? Or is it now the same? It seems like the sudo_unchecked_weight, unlike this one, can be just called signed with the sudo key, and then it won't qualify as "run through the sudo pallet" as you've put it, which means the Pays::No is in fact required there. Correct?

[bkchr]

I see. So, the sudo_unchecked_weight at pallet_sudo can also effectively omit the Pays::No, since it must be called from the sudo account?

Yes it can only be called by the sudo account, but in this case by the "real account". It uses ensure_signed to ensure that this is called by a normal account (which should be the sudo account) and then dispatches the call as Root. So, we should not remove the Pays::No as the caller will first need to pay for the call and then gets the fees refunded.