Unexpected Result When QLCDNumber::display is Set to INT_MIN

I have the following example:

// Testing INT_MIN handling
QLCDNumber *lcd = new QLCDNumber(12, this);
lcd->setMode(QLCDNumber::Dec);
lcd->display(INT_MIN); // Should correctly display -2147483648

// Testing other boundary values
lcd->display(INT_MAX); // Should correctly display 2147483647
lcd->display(-1); // Should correctly display -1
lcd->display(0); // Should correctly display 0

The result shows that when lcd->display(INT_MIN) is called, the displayed result is not the expected -2147483648. On Linux, I observed the result as --2147483648.

The cause is an integer overflow issue in the QLCDNumber::int2string function, as shown below:

bool negative;
if (num < 0) {
    negative = true;
    num      = -num;  // ← Integer overflow bug exists here!
} else {
    negative = false;
}

When the value of num is INT_MIN, executing num = -num causes integer overflow because:
1. The absolute value of INT_MIN is 2147483648
2. But the maximum positive value of int type (INT_MAX) is 2147483647
3. Therefore, -INT_MIN cannot be represented by the int type, resulting in overflow