C-W is deleting my command prompt - how to stop this

I'm working on a small shell and using libreadline to get command input.

problem

• My command prompt is getting deleted when I use C-W

note this only happens after I enter a word and then C-W, C-w immediately doesn't delete the prompt.

source

#include <stdio.h>
#include <readline/readline.h>
#include <readline/history.h>
#include <stdlib.h>
#include <string.h>

int ash_loop(void)
{
  char *line = 0;
  while(1)
  {
    // this is the current prompt - i dont want it to be deletable..
    printf("ash$ ");
    line = readline(0);
    if(!line)goto err0;
    printf("line: %s\n", line);
    free(line);
    break;
  }
  return 0;
  
err0:
  return 1;
}

int main(int argc, char *argv[])
{
  int rc; 
  rc = ash_loop();
  return rc; 
}

example session

$ ./ash                                                                      
line: 

here i typed word and then C-W.

How can I preserve the prompt ?

You want to use the prompt argument to readline():

line = readline("ash$ ");