Bad_alloc not thrown when I expect it to - c++

Question

Consider this simple program:
#include <exception>
#include <iostream>
int main(void)
{
const std::size_t size = 1<<31;
int *a = NULL;
try
{
a = new int[size];
}
catch (std::exception &e)
{
std::cerr << "caught some bad guy" << std::endl;
return 1;
}
if (a == NULL)
{
std::cerr << "it's null, can't touch this" << std::endl;
return 1;
}
std::cerr << "looks like 'a' is allocated alright!" << std::endl;
for (size_t i = 0; i < size; i ++)
std::cout << a[i] << " ";
return 0;
}
Commentary
I try to allocate some ridiculous amount of memory: (1<<31) * sizeof(int) == 8GB
I add safety checks
Catching std::exception, which should catch std::bad_alloc among other exceptions...
Check if it's not null (even though for this check to actually make sense, I'd need a = new (std::nothrow) int[size] - but regardless of how I allocate memory, it doesn't work)
Environment
RAM installed: 2GB
Operating system: Debian
Architecture: 32-bit
Problem
The problem is that the program, instead of early exit, does something like this:
rr-#burza:~$ g++ test.cpp -o test && ./test
looks like 'a' is allocated alright!
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
(...many other zeros here...)
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0Segmentation fault
The number of zeros printed is exactly 33790, which tells me exactly... nothing.
How can I make my program segfault-proof?

Answer 1

This seems to be a bug in your environment, which causes integer overflow in implementation of new[]. In effect, you are allocating 0 bytes. It might be this bug. C++03 standard is not clear about what should happen, in C++11 std::bad_array_new_length should be thrown.
If you need to support this system you can check if there is chance for overflow before allocating, for example:
size_t size_t_max = -1;
if (size > size_t_max / sizeof(int))
throw ...;
This bug might still affect you however if libraries you use don't have such checks (for example implementation of std::vector).