Serialization of Tumbling Window For fails

Hello

The serialization of a tumbling window for is broken. The assertion at src/zorbaserialization/class_serializer.h:399 doesn't pass. The problem can be reproduced by extending the plan_serialization unit test with the following diff:

=== modified file 'test/unit/guestbook.xq'
--- test/unit/guestbook.xq 2011-08-12 16:07:57 +0000
+++ test/unit/guestbook.xq 2011-10-12 13:06:44 +0000
@@ -37,6 +37,14 @@
       return 1
 };

+declare function guestbook:window() {
+ let $x := 1 to 1000
+ for tumbling window $w in $x
+ start at $s when fn:true()
+ end at $e when $e - $s eq 51
+ return <window>{ $w }</window>
+};
+
 declare %ann:sequential function guestbook:init() {
   ddl:create($guestbook:entries);
 };

=== modified file 'test/unit/guestbook_main.xq'
--- test/unit/guestbook_main.xq 2011-08-05 02:21:55 +0000
+++ test/unit/guestbook_main.xq 2011-10-12 12:58:13 +0000
@@ -18,4 +18,4 @@

 import module namespace refl = "http://www.zorba-xquery.com/modules/reflection";

-guestbook:init(), refl:eval("guestbook:list()")
+guestbook:init(), refl:eval("guestbook:list()"), refl:eval("guestbook:window()")

the test result is:

ctest -R plan_seri -V
UpdateCTestConfiguration from :/home/dagraf/zorba/build/DartConfiguration.tcl
Parse Config file:/home/dagraf/zorba/build/DartConfiguration.tcl
 Add coverage exclude regular expressions.
 Add coverage exclude: mapm.*
UpdateCTestConfiguration from :/home/dagraf/zorba/build/DartConfiguration.tcl
Parse Config file:/home/dagraf/zorba/build/DartConfiguration.tcl
Test project /home/dagraf/zorba/build
Constructing a list of tests
Done constructing a list of tests
Checking test dependency graph...
test 2041
    Start 2041: test/unit/plan_serializer

2041: Test command: /home/dagraf/zorba/build/test/unit/UnitTests plan_serializer
2041: Test timeout computed to be: 1500
2041: <//home/dagraf/zorba/build/test/unit/guestbook.xq>:27,25: Zorba static warning [zwarn:ZWST0003]: "guestbook:list": function declared sequential, but has non-sequential body; raised at /home/dagraf/zorba/sandbox/src/compiler/translator/translator.cpp:3399
2041: UnitTests: /home/dagraf/zorba/sandbox/src/zorbatypes/rchandle.h:111: virtual void zorba::SimpleRCObject::serialize_internal(zorba::serialization::Archiver&): Assertion `strstr(typeid(*this).name(), "SimpleRCObject")' failed.
1/1 Test #2041: test/unit/plan_serializer ........***Exception: SegFault 0.08 sec

0% tests passed, 1 tests failed out of 1

Total Test time (real) = 0.17 sec

The following tests FAILED:
 2041 - test/unit/plan_serializer (SEGFAULT)
Errors while running CTest