The check_stale_header() function now handles header_prev inside, so it doesn't have to be handled in the outer loop as check_stale_header() always sets it to the correct value of the previous header in the chain.
The check_stale_header() function now handles header_prev inside, so it doesn't have to be handled in the outer loop as check_stale_header() always sets it to the correct value of the previous header in the chain.