http://git.gnome.org/browse/libxml2/commit/?id=df83c17e5a2646bd923f75e5e507bc80d73c9722
http://git.gnome.org/browse/libxml2/commit/?id=fec31bcd452e77c10579467ca87a785b41115de6

--- xpath.c	2010-11-03 20:18:27.000000000 +0100
+++ xpath.c.oden	2010-12-29 17:48:20.978868869 +0100
@@ -11763,11 +11763,16 @@ xmlXPathCompOpEvalPositionalPredicate(xm
 
 	    if ((ctxt->error != XPATH_EXPRESSION_OK) || (res == -1)) {
 	        xmlXPathObjectPtr tmp;
-		/* pop the result */
+		/* pop the result if any */
 		tmp = valuePop(ctxt);
-		xmlXPathReleaseObject(xpctxt, tmp);
-		/* then pop off contextObj, which will be freed later */
-		valuePop(ctxt);
+                if (tmp != contextObj) {
+                    /*
+                     * Free up the result
+                     * then pop off contextObj, which will be freed later
+                     */
+                    xmlXPathReleaseObject(xpctxt, tmp);
+                    valuePop(ctxt);
+                }
 		goto evaluation_error;
 	    }