[PATCHv7] nss_db: protect against empty mappings

[Florian Weimer]

* DJ Delorie:

> +  rest = "/makedb -o /var/db/passwd.db /var/db/passwd.in";
> +  cmd = (char *) xmalloc (strlen (support_bindir_prefix)
> +				+ strlen (rest) + 1);
> +  strcpy (cmd, support_bindir_prefix);
> +  strcat (cmd, rest);
> +
> +  system (cmd);
> +
> +  try_it ();
> +  try_it ();

You could use xasprintf and free the pointer.

Thanks,
Florian