calling xmlNodeDump on a root-node of a UTF8 encoded document
para0.xml
<?xml version='1.0' encoding='utf-8'?>
<para>...some UTF8 characters here...</para>

under <= 2.6.8 and >= 2.6.15 behaves differently:

$ LD_PRELOAD=/net/su/h/local2-rh8/lib/libxml2.so.2.6.8 ./parseprint para0.xml
<para>ì¹èø¾øýáíùú»òï</para>

$ LD_PRELOAD=/net/su/h/local2-rh8/lib/libxml2.so.2.6.15 ./parseprint para0.xml
<para>&#x11B;&#x161;&#x10D;&#x159;&#x17E;&#x159;&#xFD;&#xE1;&#xED;&#x16F;&#xFA;&#x165;&#x148;&#x10F;</para>

i.e. prior to 2.6.8 non-ascii characters are UTF8, post 2.6.15 non-ascii
characters are escaped.

parseprint.c is as follows:

#include <stdio.h>
#include <libxml/parser.h>
#include <libxml/parserInternals.h>
#include <libxml/tree.h>
int
main(int argc, char **argv)
{
    xmlDoc *doc = NULL;
    xmlNode *root_element = NULL;
    const xmlChar *ret = NULL;
    xmlParserCtxtPtr ctxt;

    if (argc != 2) return(1);

    LIBXML_TEST_VERSION

    /* libxml2-2.4 API, so that we can link against older versions too */
    ctxt = xmlCreateFileParserCtxt(argv[1]);
    xmlParseDocument(ctxt);
    doc = ctxt->myDoc;
    ctxt->myDoc = NULL;
    xmlFreeParserCtxt(ctxt);

    if (doc == NULL) {
        printf("error: could not parse file %s\n", argv[1]);
    }

    /*Get the root element node */
    root_element = xmlDocGetRootElement(doc);
    xmlBufferPtr buffer;
    buffer = xmlBufferCreate();
    xmlNodeDump( buffer,
                 doc,
                 root_element, 0, 0);

    if ( xmlBufferLength(buffer) > 0 ) {
      ret = xmlBufferContent( buffer );
    }
    printf("%s\n",ret);
    xmlFreeDoc(doc);
    xmlCleanupParser();
    return 0;
}