A NullPointerException may occur when testing a match against an XSLT pattern that uses the current() function.
The problem occurs when
(a) the pattern has a predicate that invokes current()
(b) the pattern also has predicates that declare other range variables, explicitly or implicitly (in 9.0, range variables are often declared implicitly because an expression such as [* = current()] is translated to "some $x in * satisfies $x eq current()")
(c) the pattern is a path pattern including at least one "/" or "//" operator
A patch is being placed in Subversion.