malloc(sizeof * p) ?: ({goto end; nullptr;});

[thradams]

I believe the following code is not producing the expected result or diagnostics.

#include <stdio.h>
#include <stdlib.h>

int main(void) {
    int * p = malloc(sizeof * p) ?: ({goto end; nullptr;});

    end:
    return 0;
}

[thradams]

int main(void) {
    int i;
    int * p = &i ?: ({goto end; 0;});
    *p = 1;
    end:
    return 0;
}