Similarly:

parser reports no structured errors at all via a registered structured
error handler (this problem affects both XML parsing errors or
validation errors). 

Well-formedness errors can be taken from parser ctxt->lastError at the
end of parsing but validation errors can't (ctxt->lastError is ERR_OK,
only ctxt->valid == 0 indicates a validity error).

Non-structured errors are repotred in both cases. 

Here is a simple C code to test with (if given an argument, parses
that file, otherwise parses the inline XML document).

__BEGIN_TEST_CASE___
#include <stdarg.h>
#include <unistd.h>
#include <libxml/parser.h>
#include <libxml/parserInternals.h>
#include <libxml/xmlerror.h>
#include <libxml/tree.h>

char* xmldoc = 
"<?xml version='1.0'?>"
"<!DOCTYPE boo []>"
"<foo/>";

void
my_flat_err(void *ctx, const char *msg, ...) {
    printf("<Flat-error-invoked>\n");
    va_list ap;
    va_start(ap, msg);
    vfprintf(stderr, msg, ap);
    va_end(ap);
    printf("</Flat-error-invoked>\n");
}

void
my_struct_err(void *userData, xmlErrorPtr err) {
    printf("<structured-error-invoked/>\n");
}


int
main (int argn, char** argv) {
    int ret;
    xmlParserCtxtPtr ctxt;
    xmlDocPtr doc;
    xmlSetGenericErrorFunc( NULL , (xmlGenericErrorFunc) my_flat_err);    
    xmlSetStructuredErrorFunc( NULL ,
(xmlStructuredErrorFunc)my_struct_err);

    if (argn<=1) {
        ctxt = xmlCreateMemoryParserCtxt((const char*)xmldoc,
strlen(xmldoc));
        if ( ctxt->input != NULL ) {
            ctxt->input->filename = xmlStrdup((const xmlChar *) "");
        }
        xmlCtxtUseOptions(ctxt, XML_PARSE_DTDVALID);
        ret = xmlParseDocument(ctxt);
    } else {
        ctxt = xmlNewParserCtxt();
        doc = xmlCtxtReadFile(ctxt, argv[1], NULL, XML_PARSE_DTDVALID);
    }
    if (ctxt->valid == 0)
        printf("novalid\n");
    doc = ctxt->myDoc;
    xmlFreeParserCtxt(ctxt);
    /*    doc = xmlReadMemory(xmldoc, strlen(xmldoc), NULL, NULL,
XML_PARSE_DTDVALID); */
    if (doc)
        xmlFree(doc);
}

Oh, also forgot to mentioned:

Daniel, the non-structured error handler is still called several times
per error as with old libxml2 versions, while you once told me on the
list that libxml2.6.x's behaviour was to call the handler only once
per an error (at least that's how I understood it).

Thanks, Petr

Okay, I have tried to fix the structured error handling problems
you raised . It should be fixed in CVS now:

paphio:~/XML -> gcc -o tst -Iinclude tst.c .libs/libxml2.a -lm -lz
-lpthread
paphio:~/XML -> ./tst
<structured-error-invoked/>
novalid
paphio:~/XML ->

  including the XPath reporting glitches (but untested). See also
bug #126211 which is related.
  For the non-structured error handler there is still multiple
callbacks but the number is bounded per error, it used in some case
to be called once per character printed in the context, that I
tried to fix. If the issue is really critical, I could try to
fix this, but I would rather get the structured handler ready
instead.

Daniel

This should be closed in release of libxml2-2.6.5,
                                                                     
          
Daniel