[xml] Memory leak or stupid newbie error?

[Ian Pilcher <pilchman attbi com>]

I'm a brand new user of libxml (and XML), so appologies in advance if
this is a really stupid question.

I've found that a simple program which parses a DTD file and immediately
frees it is leaking memory.  Here is my program.  (BTW, this is Red Hat
Linux 7.2, libxml 2.4.10.)

#include <libxml/parser.h>
#include <stdlib.h>
#include <stdio.h>

#include <mcheck.h>


int main(int argc, char *argv[])
    {
        xmlDtdPtr       dtd;

        mtrace();

        if (argc < 2)
        {
            fprintf(stderr, "Usage: %s <DTD file>\n", argv[0]);
            exit(__LINE__);
        }

        dtd = xmlParseDTD(NULL, argv[1]);
        if (dtd == NULL)
        {
            fprintf(stderr, "%s: xmlParseDTD failed\n", argv[1]);
            exit(__LINE__);
        }

        xmlFreeDtd(dtd);

        return 0;
    }

Here is the DTD file.

<!ELEMENT atom (value, packages)>
<!ATTLIST atom type (ATOM_STRING | ATOM_LIST | ATOM_INT | ATOM_BIN)
                                                              #REQUIRED>
<!ELEMENT value (string_data | list_data | int_data | bin_data)>
<!ELEMENT string_data (#PCDATA)>
<!ELEMENT list_data (item)*>
<!ELEMENT item (#PCDATA)>
<!ELEMENT int_data (#PCDATA)>
<!ELEMENT bin_data (#PCDATA)>
<!ELEMENT packages (package)*>
<!ELEMENT package (#PCDATA)>

(The ATTLIST line is being wrapped by my e-mail client; it's one line in
the file.)

Is there something else that I should be doing?

Thanks!
-- 
========================================================================
Ian Pilcher                                           pilchman attbi com
========================================================================