Does call.dispatch make `origin` pay the fees to the network?

Question

I'm writing a hook for a pallet, this hook pop Call out of storage and execute them on behalf of a specified user through call.dispatch(origin).

My question is:
Will dispatch will make origin pay the fees associated with this Call?
If yes is that true both in a the context of a hook and in the context of a regular user triggered call causing a call.dispatch to be issued? Who pay for what if the origin of the dispatched call is different from the origin of the original call?

Answer 1

Will dispatch will make origin pay the fees associated with this Call?

No, only the signer of a transaction will pay fees for it (although there are some PRs in Substrate to make that a bit more flexible, so this answer may change).

When executing a transaction, it goes through a few phases: pre-dispatch, dispatch, and post-dispatch. The fee for the given length/weight is taken in the pre-dispatch phase, and it won't even dispatch if the account cannot pay the fees. Then dispatch happens, and any fee refund/change, if there is some, would happen in post-dispatch. So, dispatch assumes that whatever conditions for dispatch (e.g. a fee, or scheduling by referendum) have already taken place.