Small question with how NULL works

Question

this is just a small question on NULL. In the snippet below, why doesn't the do-while loop repeat when I don't enter anything for the string?

#include <stdio.h>
#include <string.h>
#include <cs50.h>

int main(int argc, char* argv[])
{
    string name;

    do
    {
        printf("Enter your name: ");
        name = GetString();
    }while(name == NULL);

    printf("%s\n", name);
}

EDIT: I checked if GetString() returns null by inserting the following into the do-while loop:

if (name == NULL) printf("Returned NULL");

The workaround was

do
{same content)while(*name == '\0')

Any now I can't even remember how the workaround worked, do strings automatically get a newline inserted at the beginning when they're initialized?

Damn.