http://expat.cvs.sourceforge.net/viewvc/expat/expat/lib/xmltok_impl.c?view=log (1.13 -> 1.15)
 http://svn.python.org/view?view=rev&revision=74429

--- lib-src/expat/xmltok/xmltok_impl.c	2008-05-07 23:19:54.000000000 +0200
+++ lib-src/expat/xmltok/xmltok_impl.c.oden	2009-08-22 01:09:46.000000000 +0200
@@ -1728,7 +1728,7 @@ void PREFIX(updatePosition)(const ENCODI
 			    const char *end,
 			    POSITION *pos)
 {
-  while (ptr != end) {
+  while (ptr < end) {
     switch (BYTE_TYPE(enc, ptr)) {
 #define LEAD_CASE(n) \
     case BT_LEAD ## n: \