Sample code to explain Divine Spirit bug

#include <iostream>

class Minion
{
private:
    int Attack, CurrentHP, MaxHP;
public:
    Minion(int atk, int hp) : Attack(atk), CurrentHP(hp), MaxHP(hp) { }

    void UseDivineSpirit()
    {
        float temp = CurrentHP;
        CurrentHP += (int)temp;
        MaxHP += (int)temp;
        std::cout << "Use DS - Hitpoints now: " << Attack << "/" << CurrentHP << std::endl;
    }
    void UseArmorPlating()
    {
        CurrentHP++;
        MaxHP++;
        std::cout << "Use AP - Hitpoints now: " << Attack << "/" << CurrentHP << std::endl;
    }
};

int main()
{
    Minion wisp(1, 1);
    wisp.UseArmorPlating();  // Now a 1/2 wisp
    for (int i = 0; i < 23; i++)  // Repeat Armor Plating and Divine Spirit 23 times
    {
        wisp.UseArmorPlating();
        wisp.UseDivineSpirit();
    }  // Wisp is now a 1/33554430
    wisp.UseArmorPlating();  // Now a 1/33554431 wisp
    wisp.UseDivineSpirit();  // Now a 1/67108863 wisp
    wisp.UseDivineSpirit();  // Now a 1/134217727 wisp
    wisp.UseDivineSpirit();  // Now a 1/268435455 wisp
    wisp.UseDivineSpirit();  // Now a 1/536870911 wisp
    wisp.UseDivineSpirit();  // Now a 1/1073741823 wisp
    wisp.UseDivineSpirit();  // Now a 1/2147483647 wisp
    return 0;
}

Output:
Use AP: 1/2
Use AP: 1/3
Use DS: 1/6
Use AP: 1/7
Use DS: 1/14
Use AP: 1/15
Use DS: 1/30
Use AP: 1/31
Use DS: 1/62
Use AP: 1/63
Use DS: 1/126
Use AP: 1/127
Use DS: 1/254
Use AP: 1/255
Use DS: 1/510
Use AP: 1/511
Use DS: 1/1022
Use AP: 1/1023
Use DS: 1/2046
Use AP: 1/2047
Use DS: 1/4094
Use AP: 1/4095
Use DS: 1/8190
Use AP: 1/8191
Use DS: 1/16382
Use AP: 1/16383
Use DS: 1/32766
Use AP: 1/32767
Use DS: 1/65534
Use AP: 1/65535
Use DS: 1/131070
Use AP: 1/131071
Use DS: 1/262142
Use AP: 1/262143
Use DS: 1/524286
Use AP: 1/524287
Use DS: 1/1048574
Use AP: 1/1048575
Use DS: 1/2097150
Use AP: 1/2097151
Use DS: 1/4194302
Use AP: 1/4194303
Use DS: 1/8388606
Use AP: 1/8388607
Use DS: 1/16777214
Use AP: 1/16777215
Use DS: 1/33554430
Use AP: 1/33554431
Use DS: 1/67108863
Use DS: 1/134217727
Use DS: 1/268435455
Use DS: 1/536870911
Use DS: 1/1073741823
Use DS: 1/2147483647