Re: [xml] Retrieving boolean/number/string value from XPath objects

[Thomas Broyer <tbroyer ltgt net>]

Le 14/05/01 21:19:53, Daniel Veillard a écrit :
>   The code is nice, thanks a lot, recompiled, I found just one
> small bit about xmlXPathCastNodeSetToBoolean() which is not static
> but not exported either. It should probably be added to xpath.h
>
>   The problem came when recompiling libxslt against it and running
> the tests. I detected some memory leaks. I didn't found where exactly,
> what I suspect is that there has been a small change in one of the
> API (seems related to ID lookups) which generates this leak,
>
>   I will try to find it and will commit this once found,

Found!

tokens isn't freed in the loop in xmlXPathIdFunction.

Also, I used xmlConvertString in the case the argument isn't a node-set. I
should have used tokens = xmlXPathCastToString(obj); and then, to free both
obj and tokens without memory leak:
  if (obj->type != XPATH_STRING) {
    /* another possibility is tokens != obj->stringval */
    xmlFree(tokens);
  }
  xmlXPathFreeObject(obj);

I'll make a piece of the interface I explained in "XPath extension API" so
that the code will become something like this:
void
xmlXPathIdFunction (... ctxt, int nargs);
  ...
  if (nargs != 1) {
    xmlXPathSetInvalidArity(ctxt);
    return;
  }
  if (xmlXPathStackType(ctxt) == XPATH_NODESET) {
    ...
    obj = xmlXPathPopNodeSet(ctxt);
      /* here comes the loop */
    xmlXPathFreeNodeSet(obj);
  } else {
    tokens = xmlXPathPopString(ctxt);
    ret = xmlXPathGetElementsByIds(xmlXPathGetDocument(ctxt), tokens);
    xmlFree(tokens);
  }
  xmlXPathReturnNodeSet(ret);
}

No need to burden ourselves with xmlXPathObjects when we don't need them.

Tom.