https://bugs.gentoo.org/show_bug.cgi?id=280615
 http://svn.python.org/view?view=rev&revision=74429

--- expat/xmltok_impl.c	2001-09-08 00:25:35.000000000 +0200
+++ expat/xmltok_impl.c.oden	2009-08-21 23:21:16.000000000 +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: \