malloc with size 0

[Suma C <gsumac@gmail.com>]

Hi all

When  a 0 is passed to malloc, I get a valid pointer instead of a NULL
.What does this mean?

thanks  in advance

regards
suma

PS:
code:
#include <stdio.h>
#include <stdlib.h>

int main()
{
        char  *ptr = NULL;
        ptr = malloc(0);
        printf("ptr :%u \n",ptr);
        strcpy(ptr,"abcdefghijkl");
        printf("%s\n",ptr);  //no seg fault here????
        return 0;
}