The new `getrpcinfo` shows a list of the active commands and the duration each command has been running. This sounds like a good place to report a completion percentage for any command doing a blockchain rescan, to solve [this problem](https://bitcoin.stackexchange.com/q/83236/90721).
{
    if (!pwallet->CanGetAddresses(internal)) {
        return false;
    }
    if (nIndex == -1)
    {
        CKeyPool keypool;
        if (!pwallet->ReserveKeyFromKeyPool(nIndex, keypool, internal)) {
            return false;
        }
        vchPubKey = keypool.vchPubKey;
        fInternal = keypool.fInternal;
    }
    assert(vchPubKey.IsValid());
    pubkey = vchPubKey;
    return true;
}
void CReserveKey::KeepKey()
{
    if (nIndex != -1)
        pwallet->KeepKey(nIndex);
    nIndex = -1;
    vchPubKey = CPubKey();
}
void CReserveKey::ReturnKey()