Re: libio backward compat bug? involving setmntent()

[Ulrich Drepper <drepper@cygnus.com>]

Zack Weinberg <zack@rabi.columbia.edu> writes:

> The appended slightly-out-of-spec code segfaults when compiled on a
> libc 2.0 system and run on a libc 2.1 system.  The problem is that
> setmntent() returns a new FILE*, but fclose is bound to the old
> fclose.
> 
> Do we want to support this, and if so, how?  (Have old fclose
> recognize when it's handed a new FILE* and call _IO_new_fclose?)

There is no libc problem (at least, not really).  The program is
wrong:

>     fp = setmntent("/etc/mtab", "r");
>     while((me = getmntent(fp)) != 0)
> 	printf("%s on %s\ttype %s opts %s freq %d pass %d\n",
> 	       me->mnt_fsname, me->mnt_dir, me->mnt_type,
> 	       me->mnt_opts, me->mnt_freq, me->mnt_passno);
> 
>     fclose(fp);

This must be

      endmntent (fp);

>     return 0;
> }

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