Some remarks about the patch:
1 - this line causes a buffer overrun:
    strncpy(argv[0], name , strlen(name));
A possible solution is to do like posix_putenv(): have a static PyString
that holds the memory, and just change the pointer argv[0]:
    argv[0] = PyString_AS_STRING(name);

2 - The function should update sys.argv as well. In this case,
os.getprocname is not necessary.