Re: [PATCH] grep: make echo .|grep '\.' match once again

[Paul Eggert]

Thanks for catching the bug that I introduced. I looked for a similar bug in 
update_patterns but it does the right thing.

>        memcpy (keys, new_keys, p - new_keys);
> +      /* We have just shortened this pattern.
> +         Preserve the invariant that it is newline-terminated.  */
> +      keys[*len_p] = '\n';

This could be:

    char *keys_end = mempcpy (keys, new_keys, p - new_keys);
    *keys_end = '\n';

to save a few instructions and arguably make it a bit clearer.