CDATA text nodes can cause ctxt->lasttsize to be incorrect, bug?

/*
 * adapted from libxslt_tutorial.c:
 * http://xmlsoft.org/xslt/tutorial/libxslttutorial.html
 */

#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <libxml/xmlmemory.h>
#include <libxslt/xslt.h>
#include <libxslt/transform.h>
#include <libxslt/xsltutils.h>

static const int MAGIC = 0x12345678;

typedef struct {
    size_t size;
    int magic;
} memheader;
typedef struct {
    int magic;
    size_t size;
} memfooter;

void* get_mem(memheader *header) {
    return ((void*)header) + sizeof(memheader);
}
memheader* get_memheader(void *mem) {
    return mem - sizeof(memheader);
}
memfooter* get_memfooter(memheader *header) {
    return ((void*) header) + sizeof(memheader) + header->size;
}
void check_head_foot(void *mem) {
    memheader *header = get_memheader(mem);
    memfooter *footer = get_memfooter(header);
    assert(header->magic == MAGIC);
    assert(footer->magic == MAGIC);
    assert(header->size == footer->size);
}

void checked_free(void *mem) {
    if (!mem) return;
    check_head_foot(mem);
    free(get_memheader(mem));
}
void* checked_malloc(size_t size) {
    memfooter *footer;
    memheader *header = malloc(size + sizeof(memheader) + sizeof(memfooter));
    header->magic = MAGIC;
    header->size = size;
    footer = get_memfooter(header);
    footer->magic = MAGIC;
    footer->size = size;
    return get_mem(header);
}
void* checked_realloc(void *mem, size_t size) {
    memfooter *footer;
    memheader *header;
    if (mem) check_head_foot(mem);
    header = realloc(mem? get_memheader(mem) : NULL, size + sizeof(memheader) + sizeof(memfooter));
    header->magic = MAGIC;
    header->size = size;
    footer = get_memfooter(header);
    footer->magic = MAGIC;
    footer->size = size;
    return get_mem(header);
}
char* checked_strdup(const char *str) {
    int len = strlen(str);
    char *newstr = checked_malloc(len+1);
    memcpy(newstr, str, len);
    newstr[len] = '\0';
    return newstr;
}

extern int xmlLoadExtDtdDefaultValue;

static void usage(const char *name) {
    printf("Usage: %s stylesheet <xsl-file> <xml-file>\n", name);
}

int
main(int argc, char **argv) {
    int i = 1;
    xsltStylesheetPtr cur;
    xmlDocPtr doc, res, style_doc;

    if (argc <= 1) {
        usage(argv[0]);
        return(1);
    }

    xmlInitMemory();
    xmlMemSetup(checked_free, checked_malloc, checked_realloc, checked_strdup);

    xmlSubstituteEntitiesDefault(1);
    xmlLoadExtDtdDefaultValue = 1;
    /* passing XML_PARSE_NOCDATA avoid crash */
    style_doc = xmlReadFile(argv[i], NULL, 0);
    cur = xsltParseStylesheetDoc(style_doc);
    i++;
    doc = xmlParseFile(argv[i]);
    res = xsltApplyStylesheet(cur, doc, NULL);
    xsltSaveResultToFile(stdout, res, cur);

    xsltFreeStylesheet(cur);
    xmlFreeDoc(res);
    xmlFreeDoc(doc);

    xsltCleanupGlobals();
    xmlCleanupParser();
    return(0);
}

<?xml version="1.0" encoding="UTF-8" ?>
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