multiprecision: Number is not assigned after dividing zero by something.

[Stepan Podoskin <stepik-777@…>]

#include <iostream>
#include <boost/multiprecision/cpp_int.hpp>
using boost::multiprecision::cpp_int;

int main()
{
    cpp_int a = 1;
    a = 0/cpp_int("1");
    std::cout << "a = " << a << "\n"; // a = 1
    return 0;
}

divide.hpp: line 341 says All the limbs in x are zero, so is the result:

However, result is not assigned to zero.

[Stepan Podoskin <stepik-777@…>]

patch "boost/multiprecision"

[John Maddock]

Confirmed.

[John Maddock]

(In [83128]) Fix bug in division of zero. Document and add tests. Fixes #8160.

[Stepan Podoskin <stepik-777@…>]

I just want to note that comparison with zero here isn't necessary.

There is:

   if((r_order == 0) && (*pr == 0))

And few lines below:

   if((r_order == 0) && (*pr < y))

There is no reason to treat zero as some special value, it will be handled by second if, so lines 339-345 can be simply removed.

[John Maddock]

Um.. clearly the bug I have at present has eaten my brains away :-(

Will fix shortly, thanks for your patience!

[John Maddock]

(In [83153]) Better fix for #8160. Refs #8160.