Weird results for conditional operator with GCC and bool pointers

Question

In the following code, I memset() a stdbool.h bool variable to value 123. (Perhaps this is undefined behaviour?) Then I pass a pointer to this variable to a victim function, which tries to protect against unexpected values using a conditional operation. However, GCC for some reason seems to remove the conditional operation altogether.

#include <stdio.h>
#include <stdbool.h>
#include <string.h>

void victim(bool* foo)
{
    int bar = *foo ? 1 : 0;
    printf("%d\n", bar);
}

int main()
{
    bool x;
    bool *foo = &x;
    memset(foo, 123, sizeof(bool));
    victim(foo);
    return 0;
}

user@host:~$ gcc -Wall -O0 test.c
user@host:~$ ./a.out 
123

What makes this particularly annoying is that the victim() function is actually inside a library, and will crash if the value is more than 1.

Reproduced on GCC versions 4.8.2-19ubuntu1 and 4.7.2-5. Not reproduced on clang.