Player::LoadFromDB in player.cpp

if (time_diff > 0)
    {
        //speed collect rest bonus in offline, in logout, far from tavern, city (section/in hour)
        float bubble0;
        //speed collect rest bonus in offline, in logout, in tavern, city (section/in hour)
        float bubble1;
        // If has Inner Peace give double rest exp.
        if (HasSpell(90168))
        {
            bubble0 = .062f;
            bubble1 = .25f;
        }
        else
        {
            bubble0 = 0.031f;
            bubble1 = 0.125f;
        }
        float bubble = fields[28].GetUInt8() > 0
            ? bubble1*sWorld->getRate(RATE_REST_OFFLINE_IN_TAVERN_OR_CITY)
            : bubble0*sWorld->getRate(RATE_REST_OFFLINE_IN_WILDERNESS);

        SetRestBonus(GetRestBonus() + time_diff*((float)GetUInt32Value(PLAYER_NEXT_LEVEL_XP) / 72000)*bubble);
    }