Function stbi__addints_valid

Source/Utils/stb_image.h:1069–1074

returns 1 if the sum of two signed ints is valid (between -2^31 and 2^31-1 inclusive), 0 on overflow.

// returns 1 if the sum of two signed ints is valid (between -2^31 and 2^31-1 inclusive), 0 on overflow.
static int stbi__addints_valid(int a, int b)
{
   if ((a >= 0) != (b >= 0)) return 1; // a and b have different signs, so no overflow
   if (a < 0 && b < 0) return a >= INT_MIN - b; // same as a + b >= INT_MIN; INT_MIN - b cannot overflow since b < 0.
   return a <= INT_MAX - b;
}

// returns 1 if the product of two ints fits in a signed short, 0 on overflow.
static int stbi__mul2shorts_valid(int a, int b)