zodbdump: Fix pickle disassembly if state part of zpickle refers to class part

I've tried to run `zodb dump --pretty=zpickledis` on wendelin.core test
data in WCFS(*) and hit the following failure:

    (z-dev) kirr@deca:~/src/wendelin/wendelin.core/wcfs/internal/zdata/testdata$ zodb dump --pretty=zpickledis zblk.fs
    ...
    obj 0000000000000005 685 sha1:865171b709f575b355afd2cc9e1f32b9781c6510
    Traceback (most recent call last):
      File "/home/kirr/src/wendelin/venv/z-dev/bin/zodb", line 11, in <module>
        load_entry_point('zodbtools', 'console_scripts', 'zodb')()
      File "/home/kirr/src/wendelin/z/zodbtools/zodbtools/zodb.py", line 129, in main
        return command_module.main(argv)
      File "<decorator-gen-3>", line 2, in main
      File "/home/kirr/src/wendelin/venv/z-dev/lib/python2.7/site-packages/golang/__init__.py", line 103, in _
        return f(*argv, **kw)
      File "/home/kirr/src/wendelin/z/zodbtools/zodbtools/zodbdump.py", line 341, in main
        zodbdump(stor, tidmin, tidmax, hashonly, pretty)
      File "/home/kirr/src/wendelin/z/zodbtools/zodbtools/zodbdump.py", line 167, in zodbdump
        pickletools.dis(dataf, disf) # state
      File "/usr/lib/python2.7/pickletools.py", line 2005, in dis
        raise ValueError(errormsg)
    ValueError: memo key 1 has never been stored into

The problem turned out to be due to that state part of zpickle is
referring to another object with the same class as already saved
in class part of zpickle, so that class was being referred to via GET
matching corresponding PUT done in the class part, but our zpickledis
handler did not shared the memo in between those two parts and so the
GET became unmatched.

In more details the problem is illustrated by the following zpickle that
corresponds to Object.value referring to the same Object. The first part
of zpickle contains class part and refers to __main__.Object global
with putting it into memo[1]. The second part of zpickle contains state
part and refers to that object by `(Object, 7) PERSID` where Object is
retrieved via memo[1] GET:

    obj 0000000000000007 41 sha1:7108c96ccb9cbeaab1164d533174c300e51309f9
          0: \x80 PROTO      2
          2: c    GLOBAL     '__main__ Object'
         19: q    BINPUT     1                   <-- NOTE
         21: .    STOP
      highest protocol among opcodes = 2
         22: \x80 PROTO      2
         24: U    SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x07'
         34: q    BINPUT     2
         36: h    BINGET     1                   <-- NOTE
         38: \x86 TUPLE2
         39: Q    BINPERSID
         40: .    STOP
      highest protocol among opcodes = 2

To handle such zpickles well we need to share the memo when dumping
class and state disassemblies similarly to how ZODB does in its
ObjectWriter._dump:

https://github.com/zopefoundation/ZODB/blob/5.8.1-0-g72cebe6bc/src/ZODB/serialize.py#L436-L443

Pickletools.dis has explicit support for using shared memo - originally
added in https://github.com/python/cpython/commit/62235e701e37 and
likely motivated by ZODB use-case.

(*) https://lab.nexedi.com/nexedi/wendelin.core/-/blob/07087ec8/wcfs/internal/zdata/testdata/zblk.fs
    generated by nexedi/wendelin.core@2c152d41

/reviewed-by @jerome
/reviewed-on nexedi/zodbtools!28

zodbtools/test/gen_testdata.py

 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
-# Copyright (C) 2017-2023  Nexedi SA and Contributors.
+# Copyright (C) 2017-2024  Nexedi SA and Contributors.
 #                          Kirill Smelkov <kirr@nexedi.com>
 #
 # This program is free software: you can Use, Study, Modify and Redistribute
@@ -230,6 +230,14 @@ def _gen_testdb(outfs_path, zext):
 
                 break
 
+        # create a cyclic object -> object reference
+        # pretty=zpickledis used not to handle this well because in ZODB pickle the reference
+        # referes to referred type by GET that is prepared by PUT in class part of the pickle.
+        name = random.choice(list(root.keys()))
+        obj = root[name]
+        obj.value = obj
+        commit(u"user", u"cyclic reference", ext("cycle"))
+
         # delete an object
         name = random.choice(list(root.keys()))
         obj = root[name]

zodbtools/test/test_analyze.py

 # -*- coding: utf-8 -*-
-# Copyright (C) 2019-2023 Nexedi SA and Contributors.
+# Copyright (C) 2019-2024 Nexedi SA and Contributors.
 #
 # This program is free software: you can Use, Study, Modify and Redistribute
 # it under the terms of the GNU General Public License version 3, or (at your
@@ -40,7 +40,7 @@ def test_zodbanalyze(tmpdir, capsys):
             csv=False,
         )
         captured = capsys.readouterr()
-        assert "Processed 68 records in 65 transactions" in captured.out
+        assert "Processed 70 records in 67 transactions" in captured.out
         assert captured.err == ""
 
     # csv output
@@ -57,8 +57,8 @@ def test_zodbanalyze(tmpdir, capsys):
     captured = capsys.readouterr()
     assert (
         """Class Name,T.Count,T.Bytes,Pct,AvgSize,C.Count,C.Bytes,O.Count,O.Bytes
-persistent.mapping.PersistentMapping,3,639,23.194192%,213.000000,1,213,2,426
-__main__.Object,63,2116,76.805808%,33.587302,9,303,54,1813
+persistent.mapping.PersistentMapping,3,639,22.468354%,213.000000,1,213,2,426
+__main__.Object,65,2205,77.531646%,33.923077,9,310,56,1895
 """
         == captured.out
     )

zodbtools/test/testdata/1.zdump.zpickledis.ok

@@ -56,35 +56,6 @@ obj 0000000000000006 34 sha1:5dbf26359289e5a25f9755f832ea91cc8ee76686
   highest protocol among opcodes = 2
 
 
-txn 0285cbac917e4b4c "p"
-user "user0.18"
-description "step 0.18"
-extension
-      0: \x80 PROTO      2
-      2: }    EMPTY_DICT
-      3: q    BINPUT     1
-      5: (    MARK
-      6: U        SHORT_BINSTRING 'x-generator'
-     19: q        BINPUT     2
-     21: U        SHORT_BINSTRING 'zodb/py2 (b)'
-     35: U        SHORT_BINSTRING 'x-cookieO'
-     46: U        SHORT_BINSTRING 'CQUX6'
-     53: u        SETITEMS   (MARK at 5)
-     54: .    STOP
-  highest protocol among opcodes = 2
-obj 0000000000000004 34 sha1:551bc2fad39058879f4ba00a9c53d0d63b127bb1
-      0: \x80 PROTO      2
-      2: c    GLOBAL     '__main__ Object'
-     19: q    BINPUT     1
-     21: .    STOP
-  highest protocol among opcodes = 2
-     22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'b0.18'
-     31: q    BINPUT     2
-     33: .    STOP
-  highest protocol among opcodes = 2
-
-
 txn 0285cbac962fc999 "p"
 user "user0.19"
 description "step 0.19"
@@ -173,10 +144,42 @@ obj 0000000000000003 34 sha1:484358413b2746e8a05b1e3173051abedd28e1fa
 
 
 txn 0285cbacbbbbbc00 "p"
+user "user"
+description "cyclic reference"
+extension
+      0: \x80 PROTO      2
+      2: }    EMPTY_DICT
+      3: q    BINPUT     1
+      5: (    MARK
+      6: U        SHORT_BINSTRING 'x-cookieE'
+     17: U        SHORT_BINSTRING 'ZM3QZ'
+     24: U        SHORT_BINSTRING 'x-generator'
+     37: q        BINPUT     2
+     39: U        SHORT_BINSTRING 'zodb/py2 (cycle)'
+     57: u        SETITEMS   (MARK at 5)
+     58: .    STOP
+  highest protocol among opcodes = 2
+obj 0000000000000007 41 sha1:7108c96ccb9cbeaab1164d533174c300e51309f9
+      0: \x80 PROTO      2
+      2: c    GLOBAL     '__main__ Object'
+     19: q    BINPUT     1
+     21: .    STOP
+  highest protocol among opcodes = 2
+     22: \x80 PROTO      2
+     24: U    SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x07'
+     34: q    BINPUT     2
+     36: h    BINGET     1
+     38: \x86 TUPLE2
+     39: Q    BINPERSID
+     40: .    STOP
+  highest protocol among opcodes = 2
+
+
+txn 0285cbacc06d3a4c "p"
 user ""
-description "predelete 7"
+description "predelete 4"
 extension ""
-obj 0000000000000000 213 sha1:9eba67326a7fd2393c39966bfc7d7be2a8035dfa
+obj 0000000000000000 213 sha1:a6e70638fafd4619841032356ae93a4da7b539c5
       0: \x80 PROTO      2
       2: c    GLOBAL     'persistent.mapping PersistentMapping'
      40: q    BINPUT     1
@@ -198,13 +201,13 @@ obj 0000000000000000 213 sha1:9eba67326a7fd2393c39966bfc7d7be2a8035dfa
      94: \x86     TUPLE2
      95: Q        BINPERSID
      96: U        SHORT_BINSTRING 'c'
-     99: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x08'
+     99: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x07'
     109: q        BINPUT     7
     111: h        BINGET     6
     113: \x86     TUPLE2
     114: Q        BINPERSID
     115: U        SHORT_BINSTRING 'b'
-    118: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x04'
+    118: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x08'
     128: q        BINPUT     8
     130: h        BINGET     6
     132: \x86     TUPLE2
@@ -238,51 +241,22 @@ obj 0000000000000000 213 sha1:9eba67326a7fd2393c39966bfc7d7be2a8035dfa
     212: .    STOP
   highest protocol among opcodes = 2
 
-obj 0000000000000008 32 sha1:c0517df3bfc49dcda73c2797fb957c92bc651888
+obj 0000000000000008 32 sha1:936674657cf846998d27356363832827fa612092
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'c0*'
+     24: U    SHORT_BINSTRING 'b0*'
      29: q    BINPUT     2
      31: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbad02222280 " "
+txn 0285cbad06d3a0cc " "
 user "user1.0"
 description "step 1.0"
-extension
-      0: \x80 PROTO      2
-      2: }    EMPTY_DICT
-      3: q    BINPUT     1
-      5: (    MARK
-      6: U        SHORT_BINSTRING 'x-cookie3'
-     17: U        SHORT_BINSTRING '7P0TJ'
-     24: U        SHORT_BINSTRING 'x-generator'
-     37: q        BINPUT     2
-     39: U        SHORT_BINSTRING 'zodb/py2 (c)'
-     53: u        SETITEMS   (MARK at 5)
-     54: .    STOP
-  highest protocol among opcodes = 2
-obj 0000000000000008 33 sha1:064279cb7fe24286e7ec0c47704a75eedc5dfc85
-      0: \x80 PROTO      2
-      2: c    GLOBAL     '__main__ Object'
-     19: q    BINPUT     1
-     21: .    STOP
-  highest protocol among opcodes = 2
-     22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'c1.0'
-     30: q    BINPUT     2
-     32: .    STOP
-  highest protocol among opcodes = 2
-
-
-txn 0285cbad06d3a0cc " "
-user "user1.1"
-description "step 1.1"
 extension
       0: \x80 PROTO      2
       2: }    EMPTY_DICT
@@ -296,22 +270,22 @@ extension
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000006 33 sha1:3362a180bda38de9551456e11aba3a50b3ee4063
+obj 0000000000000006 33 sha1:f18e991b87b63cf1f9486d74d70020ff8d573eec
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'e1.1'
+     24: U    SHORT_BINSTRING 'e1.0'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
 txn 0285cbad0b851f19 " "
-user "user1.2"
-description "step 1.2"
+user "user1.1"
+description "step 1.1"
 extension
       0: \x80 PROTO      2
       2: }    EMPTY_DICT
@@ -325,22 +299,22 @@ extension
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000004 33 sha1:78395e22e884588e5c8037d6d90a697105722708
+obj 0000000000000008 33 sha1:c37e1d2350c8fc4e18cdbc53b432dba50e5196ba
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'b1.2'
+     24: U    SHORT_BINSTRING 'b1.1'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
 txn 0285cbad10369d66 " "
-user "user1.3"
-description "step 1.3"
+user "user1.2"
+description "step 1.2"
 extension
       0: \x80 PROTO      2
       2: }    EMPTY_DICT
@@ -354,22 +328,22 @@ extension
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000003 33 sha1:5fb466e36ea6f847b73ad7976def8ad60e00e766
+obj 0000000000000003 33 sha1:28e9880fc0f50a9fea5c4a9e861adc1fe44c9f5c
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'g1.3'
+     24: U    SHORT_BINSTRING 'g1.2'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
 txn 0285cbad14e81bb3 " "
-user "user1.4"
-description "step 1.4"
+user "user1.3"
+description "step 1.3"
 extension
       0: \x80 PROTO      2
       2: }    EMPTY_DICT
@@ -383,22 +357,22 @@ extension
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000003 33 sha1:15a38343610d25057cd88521669671350eb0c0a8
+obj 0000000000000003 33 sha1:5fb466e36ea6f847b73ad7976def8ad60e00e766
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'g1.4'
+     24: U    SHORT_BINSTRING 'g1.3'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
 txn 0285cbad19999a00 " "
-user "user1.5"
-description "step 1.5"
+user "user1.4"
+description "step 1.4"
 extension
       0: \x80 PROTO      2
       2: }    EMPTY_DICT
@@ -412,22 +386,22 @@ extension
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000008 33 sha1:fd3a56403fb6da1f975676b50d745284f187029d
+obj 0000000000000007 33 sha1:90b0ffa657df9de708913a2cbbd454126fd9de15
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'c1.5'
+     24: U    SHORT_BINSTRING 'c1.4'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
 txn 0285cbad1e4b184c " "
-user "user1.6"
-description "step 1.6"
+user "user1.5"
+description "step 1.5"
 extension
       0: \x80 PROTO      2
       2: }    EMPTY_DICT
@@ -441,22 +415,22 @@ extension
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000001 33 sha1:4d811fcaaa707127f5f6f49dc368ffd2ebae1018
+obj 0000000000000001 33 sha1:70b0a88b7652b82b82539800484dc7788277f32a
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'f1.6'
+     24: U    SHORT_BINSTRING 'f1.5'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
 txn 0285cbad22fc9699 " "
-user "user1.7"
-description "step 1.7"
+user "user1.6"
+description "step 1.6"
 extension
       0: \x80 PROTO      2
       2: }    EMPTY_DICT
@@ -470,22 +444,22 @@ extension
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000002 33 sha1:4c3e1f41eebd1f56c0fef1f609d64e061a137f5a
+obj 0000000000000002 33 sha1:e9018b0bc67c9de08becf1f1fe1a548ed263fb29
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'd1.7'
+     24: U    SHORT_BINSTRING 'd1.6'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
 txn 0285cbad27ae14e6 " "
-user "user1.8"
-description "step 1.8"
+user "user1.7"
+description "step 1.7"
 extension
       0: \x80 PROTO      2
       2: }    EMPTY_DICT
@@ -499,22 +473,22 @@ extension
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000008 33 sha1:13e366fb1d15d36a62099e6b835638407718229f
+obj 0000000000000007 33 sha1:0cd3f4b725517a5371429e2ef2f56ea54fe405fb
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'c1.8'
+     24: U    SHORT_BINSTRING 'c1.7'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
 txn 0285cbad2c5f9333 " "
-user "user1.9"
-description "step 1.9"
+user "user1.8"
+description "step 1.8"
 extension
       0: \x80 PROTO      2
       2: }    EMPTY_DICT
@@ -528,22 +502,22 @@ extension
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000008 33 sha1:beb7a6ebd477848306328f613a6bc214144ba14a
+obj 0000000000000007 33 sha1:13e366fb1d15d36a62099e6b835638407718229f
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'c1.9'
+     24: U    SHORT_BINSTRING 'c1.8'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
 txn 0285cbad31111180 " "
-user "user1.10"
-description "step 1.10"
+user "user1.9"
+description "step 1.9"
 extension
       0: \x80 PROTO      2
       2: }    EMPTY_DICT
@@ -557,22 +531,22 @@ extension
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000006 34 sha1:3d8eb2e84c17af9e6ffe4c2dab6a8d4180b3717c
+obj 0000000000000006 33 sha1:3ac37991a56061c7407cc093ee2a71eef4379131
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'e1.10'
-     31: q    BINPUT     2
-     33: .    STOP
+     24: U    SHORT_BINSTRING 'e1.9'
+     30: q    BINPUT     2
+     32: .    STOP
   highest protocol among opcodes = 2
 
 
 txn 0285cbad35c28fcc " "
-user "user1.11"
-description "step 1.11"
+user "user1.10"
+description "step 1.10"
 extension
       0: \x80 PROTO      2
       2: }    EMPTY_DICT
@@ -586,22 +560,22 @@ extension
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000005 34 sha1:3e2ce7b87adc999c578dec26c3d9a7148b169d50
+obj 0000000000000005 34 sha1:407cc5710a22f6c387df45aab613aa3673b221c6
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'a1.11'
+     24: U    SHORT_BINSTRING 'a1.10'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
 txn 0285cbad3a740e19 " "
-user "user1.12"
-description "step 1.12"
+user "user1.11"
+description "step 1.11"
 extension
       0: \x80 PROTO      2
       2: }    EMPTY_DICT
@@ -615,22 +589,22 @@ extension
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000008 34 sha1:d7a594303b8f49334430312211b65f06586d4e72
+obj 0000000000000007 34 sha1:88ab1add11652101077535c03b04e83fe4ddb88b
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'c1.12'
+     24: U    SHORT_BINSTRING 'c1.11'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
 txn 0285cbad3f258c66 " "
-user "user1.13"
-description "step 1.13"
+user "user1.12"
+description "step 1.12"
 extension
       0: \x80 PROTO      2
       2: }    EMPTY_DICT
@@ -644,22 +618,22 @@ extension
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000006 34 sha1:1b5a346d8929e52eb078f442c300d26e125e4200
+obj 0000000000000006 34 sha1:4808aef147f8ded08ffaae2ce04265506385e7f7
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'e1.13'
+     24: U    SHORT_BINSTRING 'e1.12'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
 txn 0285cbad43d70ab3 " "
-user "user1.14"
-description "step 1.14"
+user "user1.13"
+description "step 1.13"
 extension
       0: \x80 PROTO      2
       2: }    EMPTY_DICT
@@ -673,22 +647,22 @@ extension
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000003 34 sha1:e5b3820378e102a61be2b5998ded3182c106c7db
+obj 0000000000000003 34 sha1:a9f47880096587b359fa7ea6a0fd213e800a24a4
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'g1.14'
+     24: U    SHORT_BINSTRING 'g1.13'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
 txn 0285cbad48888900 " "
-user "user1.15"
-description "step 1.15"
+user "user1.14"
+description "step 1.14"
 extension
       0: \x80 PROTO      2
       2: }    EMPTY_DICT
@@ -702,22 +676,22 @@ extension
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000003 34 sha1:2e9ebc331bf53c095e9573de64a9b31f2b340b2f
+obj 0000000000000003 34 sha1:e5b3820378e102a61be2b5998ded3182c106c7db
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'g1.15'
+     24: U    SHORT_BINSTRING 'g1.14'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
 txn 0285cbad4d3a074c " "
-user "user1.16"
-description "step 1.16"
+user "user1.15"
+description "step 1.15"
 extension
       0: \x80 PROTO      2
       2: }    EMPTY_DICT
@@ -731,22 +705,22 @@ extension
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000002 34 sha1:3faf2b3ec22270e84cebb4d3b892e77b02d2ac10
+obj 0000000000000002 34 sha1:f136bac1befa0fbd1ebd50218f8d9afe00b9b0a5
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'd1.16'
+     24: U    SHORT_BINSTRING 'd1.15'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
 txn 0285cbad51eb8599 " "
-user "user1.17"
-description "step 1.17"
+user "user1.16"
+description "step 1.16"
 extension
       0: \x80 PROTO      2
       2: }    EMPTY_DICT
@@ -760,22 +734,22 @@ extension
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000003 34 sha1:732fac4aa308c29fba8b0da4d0502b6d35e211f4
+obj 0000000000000003 34 sha1:778621ce5c5e97b65343b1ab0cc1a3ce5702fbc8
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'g1.17'
+     24: U    SHORT_BINSTRING 'g1.16'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
 txn 0285cbad569d03e6 " "
-user "user1.18"
-description "step 1.18"
+user "user1.17"
+description "step 1.17"
 extension
       0: \x80 PROTO      2
       2: }    EMPTY_DICT
@@ -789,22 +763,22 @@ extension
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000001 34 sha1:14b40a66bb827f09c17d8a64985788a781886828
+obj 0000000000000001 34 sha1:eb6d2d192f3d8fe47a1b2e8119d390ed580c3fb4
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'f1.18'
+     24: U    SHORT_BINSTRING 'f1.17'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
 txn 0285cbad5b4e8233 " "
-user "user1.19"
-description "step 1.19"
+user "user1.18"
+description "step 1.18"
 extension
       0: \x80 PROTO      2
       2: }    EMPTY_DICT
@@ -818,22 +792,22 @@ extension
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000005 34 sha1:4f226e961b5c4f301a491442b1c820ac7dc3ce1d
+obj 0000000000000005 34 sha1:921682b323eb62f109d052bc1dfd4ffe0dbf79db
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'a1.19'
+     24: U    SHORT_BINSTRING 'a1.18'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
 txn 0285cbad60000080 " "
-user "user1.20"
-description "step 1.20"
+user "user1.19"
+description "step 1.19"
 extension
       0: \x80 PROTO      2
       2: }    EMPTY_DICT
@@ -847,22 +821,22 @@ extension
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000003 34 sha1:6bfd3298d0bea74cfa3d1f01bb722e958e3f1520
+obj 0000000000000003 34 sha1:b0b31eb0b48548119153628eb3c6711d959e9f9b
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'g1.20'
+     24: U    SHORT_BINSTRING 'g1.19'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
 txn 0285cbad64b17ecc " "
-user "user1.21"
-description "step 1.21"
+user "user1.20"
+description "step 1.20"
 extension
       0: \x80 PROTO      2
       2: }    EMPTY_DICT
@@ -876,22 +850,22 @@ extension
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000003 34 sha1:443fc48b546d0c85d01a485607253180c5624bdf
+obj 0000000000000003 34 sha1:6bfd3298d0bea74cfa3d1f01bb722e958e3f1520
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'g1.21'
+     24: U    SHORT_BINSTRING 'g1.20'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
 txn 0285cbad6962fd19 " "
-user "user1.22"
-description "step 1.22"
+user "user1.21"
+description "step 1.21"
 extension
       0: \x80 PROTO      2
       2: }    EMPTY_DICT
@@ -905,22 +879,22 @@ extension
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000006 34 sha1:5d3efa2ca7bdf3c57b08ebb4c70344f53d93a0a1
+obj 0000000000000006 34 sha1:0d4b4837500e84b190ea2f92b16ab8ec0c486db5
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'e1.22'
+     24: U    SHORT_BINSTRING 'e1.21'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
 txn 0285cbad6e147b66 " "
-user "user1.23"
-description "step 1.23"
+user "user1.22"
+description "step 1.22"
 extension
       0: \x80 PROTO      2
       2: }    EMPTY_DICT
@@ -934,22 +908,22 @@ extension
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000005 34 sha1:1b443228d5a434ddd9616ecb5aa90672c0ce9ba2
+obj 0000000000000005 34 sha1:eacbd02d0d78eece9d784da7f3fd0b2738ca6ce0
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'a1.23'
+     24: U    SHORT_BINSTRING 'a1.22'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
 txn 0285cbad72c5f9b3 " "
-user "user1.24"
-description "step 1.24"
+user "user1.23"
+description "step 1.23"
 extension
       0: \x80 PROTO      2
       2: }    EMPTY_DICT
@@ -963,14 +937,43 @@ extension
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000005 34 sha1:ad7f258dfad403eb22ab3a7f28e12ed153c45486
+obj 0000000000000005 34 sha1:1b443228d5a434ddd9616ecb5aa90672c0ce9ba2
+      0: \x80 PROTO      2
+      2: c    GLOBAL     '__main__ Object'
+     19: q    BINPUT     1
+     21: .    STOP
+  highest protocol among opcodes = 2
+     22: \x80 PROTO      2
+     24: U    SHORT_BINSTRING 'a1.23'
+     31: q    BINPUT     2
+     33: .    STOP
+  highest protocol among opcodes = 2
+
+
+txn 0285cbad77777800 " "
+user "user1.24"
+description "step 1.24"
+extension
+      0: \x80 PROTO      2
+      2: }    EMPTY_DICT
+      3: q    BINPUT     1
+      5: (    MARK
+      6: U        SHORT_BINSTRING 'x-cookieD'
+     17: U        SHORT_BINSTRING 'O5ZEM'
+     24: U        SHORT_BINSTRING 'x-generator'
+     37: q        BINPUT     2
+     39: U        SHORT_BINSTRING 'zodb/py2 (f)'
+     53: u        SETITEMS   (MARK at 5)
+     54: .    STOP
+  highest protocol among opcodes = 2
+obj 0000000000000001 34 sha1:b35a1826cc6cb71b9ddff043f0e8f88b4d90281f
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'a1.24'
+     24: U    SHORT_BINSTRING 'f1.24'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
@@ -984,15 +987,15 @@ extension
       2: }    EMPTY_DICT
       3: q    BINPUT     1
       5: (    MARK
-      6: U        SHORT_BINSTRING 'x-cookieM'
-     17: U        SHORT_BINSTRING '1G51M'
+      6: U        SHORT_BINSTRING 'x-cookie3'
+     17: U        SHORT_BINSTRING 'G51MM'
      24: U        SHORT_BINSTRING 'x-generator'
      37: q        BINPUT     2
-     39: U        SHORT_BINSTRING 'zodb/py2 (undo AoXLrWli/Rk=)'
+     39: U        SHORT_BINSTRING 'zodb/py2 (undo AoXLrXLF+bM=)'
      69: u        SETITEMS   (MARK at 5)
      70: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000006 from 0285cbad3f258c66
+obj 0000000000000005 from 0285cbad6e147b66
 
 txn 0285cbad80da7499 " "
 user "root1.1\nYour\nMagesty "
@@ -1002,21 +1005,53 @@ extension
       2: }    EMPTY_DICT
       3: q    BINPUT     1
       5: (    MARK
-      6: U        SHORT_BINSTRING 'x-cookieV'
-     17: U        SHORT_BINSTRING 'JCDRH'
+      6: U        SHORT_BINSTRING 'x-cookieL'
+     17: U        SHORT_BINSTRING 'CDRHV'
      24: U        SHORT_BINSTRING 'x-generator'
      37: q        BINPUT     2
-     39: U        SHORT_BINSTRING 'zodb/py2 (undo AoXLrXLF+bM=)'
+     39: U        SHORT_BINSTRING 'zodb/py2 (undo AoXLrXd3eAA=)'
      69: u        SETITEMS   (MARK at 5)
      70: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000005 from 0285cbad6e147b66
+obj 0000000000000001 from 0285cbad569d03e6
 
 txn 0285cbad858bf2e6 " "
+user "user"
+description "cyclic reference"
+extension
+      0: \x80 PROTO      2
+      2: }    EMPTY_DICT
+      3: q    BINPUT     1
+      5: (    MARK
+      6: U        SHORT_BINSTRING 'x-cookie4'
+     17: U        SHORT_BINSTRING 'C4OMS'
+     24: U        SHORT_BINSTRING 'x-generator'
+     37: q        BINPUT     2
+     39: U        SHORT_BINSTRING 'zodb/py2 (cycle)'
+     57: u        SETITEMS   (MARK at 5)
+     58: .    STOP
+  highest protocol among opcodes = 2
+obj 0000000000000002 41 sha1:1e2e3ac81badec749c2082a08d205c06c6bb5119
+      0: \x80 PROTO      2
+      2: c    GLOBAL     '__main__ Object'
+     19: q    BINPUT     1
+     21: .    STOP
+  highest protocol among opcodes = 2
+     22: \x80 PROTO      2
+     24: U    SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x02'
+     34: q    BINPUT     2
+     36: h    BINGET     1
+     38: \x86 TUPLE2
+     39: Q    BINPERSID
+     40: .    STOP
+  highest protocol among opcodes = 2
+
+
+txn 0285cbad8a3d7133 " "
 user ""
-description "predelete 6"
+description "predelete 3"
 extension ""
-obj 0000000000000000 213 sha1:e4b5a7c8f5537b25f27e5b9c4f6eaf6da17fc0a1
+obj 0000000000000000 213 sha1:e278899979bad10d72962170790ea2a2f5865567
       0: \x80 PROTO      2
       2: c    GLOBAL     'persistent.mapping PersistentMapping'
      40: q    BINPUT     1
@@ -1038,19 +1073,19 @@ obj 0000000000000000 213 sha1:e4b5a7c8f5537b25f27e5b9c4f6eaf6da17fc0a1
      94: \x86     TUPLE2
      95: Q        BINPERSID
      96: U        SHORT_BINSTRING 'c'
-     99: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x08'
+     99: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x07'
     109: q        BINPUT     7
     111: h        BINGET     6
     113: \x86     TUPLE2
     114: Q        BINPERSID
     115: U        SHORT_BINSTRING 'b'
-    118: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x04'
+    118: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x08'
     128: q        BINPUT     8
     130: h        BINGET     6
     132: \x86     TUPLE2
     133: Q        BINPERSID
     134: U        SHORT_BINSTRING 'e'
-    137: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\t'
+    137: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x06'
     147: q        BINPUT     9
     149: h        BINGET     6
     151: \x86     TUPLE2
@@ -1062,7 +1097,7 @@ obj 0000000000000000 213 sha1:e4b5a7c8f5537b25f27e5b9c4f6eaf6da17fc0a1
     170: \x86     TUPLE2
     171: Q        BINPERSID
     172: U        SHORT_BINSTRING 'g'
-    175: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x03'
+    175: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\t'
     185: q        BINPUT     11
     187: h        BINGET     6
     189: \x86     TUPLE2
@@ -1078,20 +1113,20 @@ obj 0000000000000000 213 sha1:e4b5a7c8f5537b25f27e5b9c4f6eaf6da17fc0a1
     212: .    STOP
   highest protocol among opcodes = 2
 
-obj 0000000000000009 32 sha1:1a43b55bc4a19245cce9eb5aa5ad411006f06afe
+obj 0000000000000009 32 sha1:38aaea7061f311a5ff41e144ea56df2c8f66435c
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'e1*'
+     24: U    SHORT_BINSTRING 'g1*'
      29: q    BINPUT     2
      31: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbad8a3d7133 " "
+txn 0285cbad8eeeef80 " "
 user "root1\nYour\nRoyal\nMagesty' \x00\x01\x02\x03\x04\x05\x06\x07\x08\t\n\x0b\x0c\r\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f"
 description "delete 1\nalpha beta gamma'delta\"lambda\n\nqqq ..."
 extension
@@ -1100,16 +1135,16 @@ extension
       3: q    BINPUT     1
       5: (    MARK
       6: U        SHORT_BINSTRING 'x-cookieS'
-     17: U        SHORT_BINSTRING 'MC4OM'
+     17: U        SHORT_BINSTRING 'XVOTI'
      24: U        SHORT_BINSTRING 'x-generator'
      37: q        BINPUT     2
-     39: U        SHORT_BINSTRING 'zodb/py2 (delete 6)'
+     39: U        SHORT_BINSTRING 'zodb/py2 (delete 3)'
      60: u        SETITEMS   (MARK at 5)
      61: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000006 delete
+obj 0000000000000003 delete
 
-txn 0285cbadc740db19 " "
+txn 0285cbadcbf25966 " "
 user "user2.0"
 description "step 2.0"
 extension
@@ -1117,28 +1152,28 @@ extension
       2: }    EMPTY_DICT
       3: q    BINPUT     1
       5: (    MARK
-      6: U        SHORT_BINSTRING 'x-cookieI'
-     17: U        SHORT_BINSTRING 'SXVOT'
+      6: U        SHORT_BINSTRING 'x-cookie1'
+     17: U        SHORT_BINSTRING 'GRGS2'
      24: U        SHORT_BINSTRING 'x-generator'
      37: q        BINPUT     2
-     39: U        SHORT_BINSTRING 'zodb/py2 (g)'
+     39: U        SHORT_BINSTRING 'zodb/py2 (f)'
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000003 33 sha1:387ba615461244d2f9ede7e1c3a06465f0d10fa0
+obj 0000000000000001 33 sha1:7b5599bdbf192e2d33e2597b52c8a72a751ddd13
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'g2.0'
+     24: U    SHORT_BINSTRING 'f2.0'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbadcbf25966 " "
+txn 0285cbadd0a3d7b3 " "
 user "user2.1"
 description "step 2.1"
 extension
@@ -1146,28 +1181,28 @@ extension
       2: }    EMPTY_DICT
       3: q    BINPUT     1
       5: (    MARK
-      6: U        SHORT_BINSTRING 'x-cookie2'
-     17: U        SHORT_BINSTRING 'SGRGS'
+      6: U        SHORT_BINSTRING 'x-cookie3'
+     17: U        SHORT_BINSTRING 'WYNK7'
      24: U        SHORT_BINSTRING 'x-generator'
      37: q        BINPUT     2
-     39: U        SHORT_BINSTRING 'zodb/py2 (b)'
+     39: U        SHORT_BINSTRING 'zodb/py2 (d)'
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000004 33 sha1:1a68c1da2be4f7b3faa4482930d7d37c1213e535
+obj 0000000000000002 33 sha1:50b0cf792f2fdc3fbfc5f47f148784924350e31c
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'b2.1'
+     24: U    SHORT_BINSTRING 'd2.1'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbadd0a3d7b3 " "
+txn 0285cbadd5555600 " "
 user "user2.2"
 description "step 2.2"
 extension
@@ -1175,15 +1210,15 @@ extension
       2: }    EMPTY_DICT
       3: q    BINPUT     1
       5: (    MARK
-      6: U        SHORT_BINSTRING 'x-cookie7'
-     17: U        SHORT_BINSTRING 'HWYNK'
+      6: U        SHORT_BINSTRING 'x-cookieF'
+     17: U        SHORT_BINSTRING 'SPFA4'
      24: U        SHORT_BINSTRING 'x-generator'
      37: q        BINPUT     2
      39: U        SHORT_BINSTRING 'zodb/py2 (g)'
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000003 33 sha1:71f1255a9751e0f223f079552e182cf26b27c0a6
+obj 0000000000000009 33 sha1:71f1255a9751e0f223f079552e182cf26b27c0a6
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
@@ -1196,7 +1231,7 @@ obj 0000000000000003 33 sha1:71f1255a9751e0f223f079552e182cf26b27c0a6
   highest protocol among opcodes = 2
 
 
-txn 0285cbadd5555600 " "
+txn 0285cbadda06d44c " "
 user "user2.3"
 description "step 2.3"
 extension
@@ -1204,28 +1239,28 @@ extension
       2: }    EMPTY_DICT
       3: q    BINPUT     1
       5: (    MARK
-      6: U        SHORT_BINSTRING 'x-cookie4'
-     17: U        SHORT_BINSTRING 'VSPFA'
+      6: U        SHORT_BINSTRING 'x-cookie1'
+     17: U        SHORT_BINSTRING 'XE3RQ'
      24: U        SHORT_BINSTRING 'x-generator'
      37: q        BINPUT     2
-     39: U        SHORT_BINSTRING 'zodb/py2 (f)'
+     39: U        SHORT_BINSTRING 'zodb/py2 (g)'
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000001 33 sha1:c80786faab0ded92976d8248ace4fb2a6be39d47
+obj 0000000000000009 33 sha1:e6236b8f0a4a2201c0c2375a8f360905108eff2d
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'f2.3'
+     24: U    SHORT_BINSTRING 'g2.3'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbadda06d44c " "
+txn 0285cbaddeb85299 " "
 user "user2.4"
 description "step 2.4"
 extension
@@ -1233,28 +1268,28 @@ extension
       2: }    EMPTY_DICT
       3: q    BINPUT     1
       5: (    MARK
-      6: U        SHORT_BINSTRING 'x-cookieQ'
-     17: U        SHORT_BINSTRING 'XXE3R'
+      6: U        SHORT_BINSTRING 'x-cookie2'
+     17: U        SHORT_BINSTRING '1XYQ2'
      24: U        SHORT_BINSTRING 'x-generator'
      37: q        BINPUT     2
-     39: U        SHORT_BINSTRING 'zodb/py2 (d)'
+     39: U        SHORT_BINSTRING 'zodb/py2 (e)'
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000002 33 sha1:39d1dc4c8bc3ea4c445db4811839801d57d5816c
+obj 0000000000000006 33 sha1:55a37439e3dc66552d680833af332b8be83bfc2a
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'd2.4'
+     24: U    SHORT_BINSTRING 'e2.4'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbaddeb85299 " "
+txn 0285cbade369d0e6 " "
 user "user2.5"
 description "step 2.5"
 extension
@@ -1262,28 +1297,28 @@ extension
       2: }    EMPTY_DICT
       3: q    BINPUT     1
       5: (    MARK
-      6: U        SHORT_BINSTRING 'x-cookie2'
-     17: U        SHORT_BINSTRING 'O1XYQ'
+      6: U        SHORT_BINSTRING 'x-cookieW'
+     17: U        SHORT_BINSTRING 'C0ZT2'
      24: U        SHORT_BINSTRING 'x-generator'
      37: q        BINPUT     2
-     39: U        SHORT_BINSTRING 'zodb/py2 (d)'
+     39: U        SHORT_BINSTRING 'zodb/py2 (a)'
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000002 33 sha1:2e472bec634f703fc24e5192114b0c61364d9273
+obj 0000000000000005 33 sha1:6beb5d1ca083744ff1e8a13c0bee70c2df54a05c
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'd2.5'
+     24: U    SHORT_BINSTRING 'a2.5'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbade369d0e6 " "
+txn 0285cbade81b4f33 " "
 user "user2.6"
 description "step 2.6"
 extension
@@ -1291,28 +1326,28 @@ extension
       2: }    EMPTY_DICT
       3: q    BINPUT     1
       5: (    MARK
-      6: U        SHORT_BINSTRING 'x-cookie2'
-     17: U        SHORT_BINSTRING '1C0ZT'
+      6: U        SHORT_BINSTRING 'x-cookie0'
+     17: U        SHORT_BINSTRING 'OX40D'
      24: U        SHORT_BINSTRING 'x-generator'
      37: q        BINPUT     2
-     39: U        SHORT_BINSTRING 'zodb/py2 (c)'
+     39: U        SHORT_BINSTRING 'zodb/py2 (b)'
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000008 33 sha1:2984bc31eaef3fc19c8d41e4fda81442a97bfbc9
+obj 0000000000000008 33 sha1:2a3221e27ac8fbf15ab75b38a9a65e727d237355
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'c2.6'
+     24: U    SHORT_BINSTRING 'b2.6'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbade81b4f33 " "
+txn 0285cbadeccccd80 " "
 user "user2.7"
 description "step 2.7"
 extension
@@ -1320,28 +1355,28 @@ extension
       2: }    EMPTY_DICT
       3: q    BINPUT     1
       5: (    MARK
-      6: U        SHORT_BINSTRING 'x-cookieD'
-     17: U        SHORT_BINSTRING '7OX40'
+      6: U        SHORT_BINSTRING 'x-cookieY'
+     17: U        SHORT_BINSTRING '64CY4'
      24: U        SHORT_BINSTRING 'x-generator'
      37: q        BINPUT     2
-     39: U        SHORT_BINSTRING 'zodb/py2 (b)'
+     39: U        SHORT_BINSTRING 'zodb/py2 (g)'
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000004 33 sha1:ca7c0222e051105fba81d7fcef12dd1358a2376c
+obj 0000000000000009 33 sha1:408fddc8c7255c5e2ed94c239ac57c211ab94b6d
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'b2.7'
+     24: U    SHORT_BINSTRING 'g2.7'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbadeccccd80 " "
+txn 0285cbadf17e4bcc " "
 user "user2.8"
 description "step 2.8"
 extension
@@ -1349,28 +1384,28 @@ extension
       2: }    EMPTY_DICT
       3: q    BINPUT     1
       5: (    MARK
-      6: U        SHORT_BINSTRING 'x-cookie4'
-     17: U        SHORT_BINSTRING 'U64CY'
+      6: U        SHORT_BINSTRING 'x-cookieZ'
+     17: U        SHORT_BINSTRING 'AXYM6'
      24: U        SHORT_BINSTRING 'x-generator'
      37: q        BINPUT     2
-     39: U        SHORT_BINSTRING 'zodb/py2 (e)'
+     39: U        SHORT_BINSTRING 'zodb/py2 (d)'
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000009 33 sha1:1b01a4beac7fd9a6dba2c81ddc85b2ebc9429cf6
+obj 0000000000000002 33 sha1:72eda0cdae0addbec9472e28b5a9a91ecdf41bbf
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'e2.8'
+     24: U    SHORT_BINSTRING 'd2.8'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbadf17e4bcc " "
+txn 0285cbadf62fca19 " "
 user "user2.9"
 description "step 2.9"
 extension
@@ -1378,28 +1413,28 @@ extension
       2: }    EMPTY_DICT
       3: q    BINPUT     1
       5: (    MARK
-      6: U        SHORT_BINSTRING 'x-cookie6'
-     17: U        SHORT_BINSTRING 'HAXYM'
+      6: U        SHORT_BINSTRING 'x-cookie8'
+     17: U        SHORT_BINSTRING '5WYSB'
      24: U        SHORT_BINSTRING 'x-generator'
      37: q        BINPUT     2
-     39: U        SHORT_BINSTRING 'zodb/py2 (c)'
+     39: U        SHORT_BINSTRING 'zodb/py2 (e)'
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000008 33 sha1:cafb08245439fbb426a30114f67d5cad33bfb738
+obj 0000000000000006 33 sha1:f1d87ba386f57291ecc925020a05df06caedb278
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'c2.9'
+     24: U    SHORT_BINSTRING 'e2.9'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbadf62fca19 " "
+txn 0285cbadfae14866 " "
 user "user2.10"
 description "step 2.10"
 extension
@@ -1407,28 +1442,28 @@ extension
       2: }    EMPTY_DICT
       3: q    BINPUT     1
       5: (    MARK
-      6: U        SHORT_BINSTRING 'x-cookieB'
-     17: U        SHORT_BINSTRING 'K5WYS'
+      6: U        SHORT_BINSTRING 'x-cookie2'
+     17: U        SHORT_BINSTRING 'F1402'
      24: U        SHORT_BINSTRING 'x-generator'
      37: q        BINPUT     2
-     39: U        SHORT_BINSTRING 'zodb/py2 (a)'
+     39: U        SHORT_BINSTRING 'zodb/py2 (c)'
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000005 34 sha1:34e522b77f14f2c10fbcdcf8e19ce9c751a3a1d0
+obj 0000000000000007 34 sha1:6696fa0434fadb645687c74c8561f0f55fce1fd6
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'a2.10'
+     24: U    SHORT_BINSTRING 'c2.10'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbadfae14866 " "
+txn 0285cbadff92c6b3 " "
 user "user2.11"
 description "step 2.11"
 extension
@@ -1436,28 +1471,28 @@ extension
       2: }    EMPTY_DICT
       3: q    BINPUT     1
       5: (    MARK
-      6: U        SHORT_BINSTRING 'x-cookie2'
-     17: U        SHORT_BINSTRING 'AF140'
+      6: U        SHORT_BINSTRING 'x-cookieG'
+     17: U        SHORT_BINSTRING 'Q5FM3'
      24: U        SHORT_BINSTRING 'x-generator'
      37: q        BINPUT     2
-     39: U        SHORT_BINSTRING 'zodb/py2 (f)'
+     39: U        SHORT_BINSTRING 'zodb/py2 (d)'
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000001 34 sha1:a29bc1058df9c09210a4c1068ecc1402b7d8a3ab
+obj 0000000000000002 34 sha1:14e8b27b3bc8bf5b4d86ca162cc1c912a29a1c05
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'f2.11'
+     24: U    SHORT_BINSTRING 'd2.11'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbadff92c6b3 " "
+txn 0285cbae04444500 " "
 user "user2.12"
 description "step 2.12"
 extension
@@ -1465,28 +1500,28 @@ extension
       2: }    EMPTY_DICT
       3: q    BINPUT     1
       5: (    MARK
-      6: U        SHORT_BINSTRING 'x-cookie3'
-     17: U        SHORT_BINSTRING 'JQ5FM'
+      6: U        SHORT_BINSTRING 'x-cookie7'
+     17: U        SHORT_BINSTRING '2EFQB'
      24: U        SHORT_BINSTRING 'x-generator'
      37: q        BINPUT     2
-     39: U        SHORT_BINSTRING 'zodb/py2 (c)'
+     39: U        SHORT_BINSTRING 'zodb/py2 (g)'
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000008 34 sha1:8c5814c88e906929b8cb85fe8728b88b6d5ea96c
+obj 0000000000000009 34 sha1:db269b90a0df33aa7d411c672f93fb7d86bbdb87
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'c2.12'
+     24: U    SHORT_BINSTRING 'g2.12'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbae04444500 " "
+txn 0285cbae08f5c34c " "
 user "user2.13"
 description "step 2.13"
 extension
@@ -1494,28 +1529,28 @@ extension
       2: }    EMPTY_DICT
       3: q    BINPUT     1
       5: (    MARK
-      6: U        SHORT_BINSTRING 'x-cookieB'
-     17: U        SHORT_BINSTRING 'Y2EFQ'
+      6: U        SHORT_BINSTRING 'x-cookieS'
+     17: U        SHORT_BINSTRING 'YS9KO'
      24: U        SHORT_BINSTRING 'x-generator'
      37: q        BINPUT     2
-     39: U        SHORT_BINSTRING 'zodb/py2 (c)'
+     39: U        SHORT_BINSTRING 'zodb/py2 (d)'
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000008 34 sha1:5d89801d288c5238f605784e7c71b2d61598d362
+obj 0000000000000002 34 sha1:4b28f9e97ff4f61f3dfba30b9f7aceb4913215ce
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'c2.13'
+     24: U    SHORT_BINSTRING 'd2.13'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbae08f5c34c " "
+txn 0285cbae0da74199 " "
 user "user2.14"
 description "step 2.14"
 extension
@@ -1523,15 +1558,15 @@ extension
       2: }    EMPTY_DICT
       3: q    BINPUT     1
       5: (    MARK
-      6: U        SHORT_BINSTRING 'x-generator'
-     19: q        BINPUT     2
-     21: U        SHORT_BINSTRING 'zodb/py2 (c)'
-     35: U        SHORT_BINSTRING 'x-cookieO'
-     46: U        SHORT_BINSTRING 'GYS9K'
+      6: U        SHORT_BINSTRING 'x-cookie5'
+     17: U        SHORT_BINSTRING 'RF8GX'
+     24: U        SHORT_BINSTRING 'x-generator'
+     37: q        BINPUT     2
+     39: U        SHORT_BINSTRING 'zodb/py2 (c)'
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000008 34 sha1:c3eabecf360015b4b7555abc3a0dc0cea77fe7ed
+obj 0000000000000007 34 sha1:c3eabecf360015b4b7555abc3a0dc0cea77fe7ed
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
@@ -1544,7 +1579,7 @@ obj 0000000000000008 34 sha1:c3eabecf360015b4b7555abc3a0dc0cea77fe7ed
   highest protocol among opcodes = 2
 
 
-txn 0285cbae0da74199 " "
+txn 0285cbae1258bfe6 " "
 user "user2.15"
 description "step 2.15"
 extension
@@ -1552,28 +1587,28 @@ extension
       2: }    EMPTY_DICT
       3: q    BINPUT     1
       5: (    MARK
-      6: U        SHORT_BINSTRING 'x-cookieX'
-     17: U        SHORT_BINSTRING 'ERF8G'
+      6: U        SHORT_BINSTRING 'x-cookie0'
+     17: U        SHORT_BINSTRING 'H70PM'
      24: U        SHORT_BINSTRING 'x-generator'
      37: q        BINPUT     2
-     39: U        SHORT_BINSTRING 'zodb/py2 (d)'
+     39: U        SHORT_BINSTRING 'zodb/py2 (e)'
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000002 34 sha1:eae3771a6fa3e632c46c51e2f29e1e314dc429e6
+obj 0000000000000006 34 sha1:25ffaeb6090581d72bce075a765d3cf4198af90f
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'd2.15'
+     24: U    SHORT_BINSTRING 'e2.15'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbae1258bfe6 " "
+txn 0285cbae170a3e33 " "
 user "user2.16"
 description "step 2.16"
 extension
@@ -1581,28 +1616,28 @@ extension
       2: }    EMPTY_DICT
       3: q    BINPUT     1
       5: (    MARK
-      6: U        SHORT_BINSTRING 'x-cookieM'
-     17: U        SHORT_BINSTRING 'MH70P'
-     24: U        SHORT_BINSTRING 'x-generator'
-     37: q        BINPUT     2
-     39: U        SHORT_BINSTRING 'zodb/py2 (d)'
+      6: U        SHORT_BINSTRING 'x-generator'
+     19: q        BINPUT     2
+     21: U        SHORT_BINSTRING 'zodb/py2 (f)'
+     35: U        SHORT_BINSTRING 'x-cookieO'
+     46: U        SHORT_BINSTRING 'MJ5PG'
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000002 34 sha1:2f75a34f0871d2b5c28d66c97108c91aeda78bd5
+obj 0000000000000001 34 sha1:e934438dede49d14ee2d1d2afa8fa18774547764
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'd2.16'
+     24: U    SHORT_BINSTRING 'f2.16'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbae170a3e33 " "
+txn 0285cbae1bbbbc80 " "
 user "user2.17"
 description "step 2.17"
 extension
@@ -1610,28 +1645,28 @@ extension
       2: }    EMPTY_DICT
       3: q    BINPUT     1
       5: (    MARK
-      6: U        SHORT_BINSTRING 'x-generator'
-     19: q        BINPUT     2
-     21: U        SHORT_BINSTRING 'zodb/py2 (c)'
-     35: U        SHORT_BINSTRING 'x-cookieG'
-     46: U        SHORT_BINSTRING 'RMJ5P'
+      6: U        SHORT_BINSTRING 'x-cookie1'
+     17: U        SHORT_BINSTRING 'RAZ4V'
+     24: U        SHORT_BINSTRING 'x-generator'
+     37: q        BINPUT     2
+     39: U        SHORT_BINSTRING 'zodb/py2 (b)'
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000008 34 sha1:2840f7eadf2b100a429e5a358f9656985827612b
+obj 0000000000000008 34 sha1:9961f82b3f01204f80efbb3b62a2b98d9d3202fa
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'c2.17'
+     24: U    SHORT_BINSTRING 'b2.17'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbae1bbbbc80 " "
+txn 0285cbae206d3acc " "
 user "user2.18"
 description "step 2.18"
 extension
@@ -1639,28 +1674,28 @@ extension
       2: }    EMPTY_DICT
       3: q    BINPUT     1
       5: (    MARK
-      6: U        SHORT_BINSTRING 'x-cookieV'
-     17: U        SHORT_BINSTRING '8RAZ4'
+      6: U        SHORT_BINSTRING 'x-cookieR'
+     17: U        SHORT_BINSTRING 'KE39A'
      24: U        SHORT_BINSTRING 'x-generator'
      37: q        BINPUT     2
-     39: U        SHORT_BINSTRING 'zodb/py2 (f)'
+     39: U        SHORT_BINSTRING 'zodb/py2 (d)'
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000001 34 sha1:ae55ca7189bdef69b9721ec5efae5ccefcecca45
+obj 0000000000000002 34 sha1:5294513e1e00c7de532f4f90068b2147bf87f673
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'f2.18'
+     24: U    SHORT_BINSTRING 'd2.18'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbae206d3acc " "
+txn 0285cbae251eb919 " "
 user "user2.19"
 description "step 2.19"
 extension
@@ -1668,28 +1703,28 @@ extension
       2: }    EMPTY_DICT
       3: q    BINPUT     1
       5: (    MARK
-      6: U        SHORT_BINSTRING 'x-cookieA'
-     17: U        SHORT_BINSTRING 'IKE39'
+      6: U        SHORT_BINSTRING 'x-cookie8'
+     17: U        SHORT_BINSTRING '1SBCJ'
      24: U        SHORT_BINSTRING 'x-generator'
      37: q        BINPUT     2
-     39: U        SHORT_BINSTRING 'zodb/py2 (b)'
+     39: U        SHORT_BINSTRING 'zodb/py2 (e)'
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000004 34 sha1:c1b57432c9e2fad36fe4a1efaa0445851865b775
+obj 0000000000000006 34 sha1:523ec17c6d74016e3464d52bb7c7b7baa4b82a20
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'b2.19'
+     24: U    SHORT_BINSTRING 'e2.19'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbae251eb919 " "
+txn 0285cbae29d03766 " "
 user "user2.20"
 description "step 2.20"
 extension
@@ -1698,27 +1733,27 @@ extension
       3: q    BINPUT     1
       5: (    MARK
       6: U        SHORT_BINSTRING 'x-cookieJ'
-     17: U        SHORT_BINSTRING 'L1SBC'
+     17: U        SHORT_BINSTRING 'EAIKM'
      24: U        SHORT_BINSTRING 'x-generator'
      37: q        BINPUT     2
-     39: U        SHORT_BINSTRING 'zodb/py2 (g)'
+     39: U        SHORT_BINSTRING 'zodb/py2 (b)'
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000003 34 sha1:3cc48a9a864cd996988559dcad0bfae9a8ac4a2c
+obj 0000000000000008 34 sha1:14b17f0e944432782cb270205b2e96948d112619
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'g2.20'
+     24: U    SHORT_BINSTRING 'b2.20'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbae29d03766 " "
+txn 0285cbae2e81b5b3 " "
 user "user2.21"
 description "step 2.21"
 extension
@@ -1727,27 +1762,27 @@ extension
       3: q    BINPUT     1
       5: (    MARK
       6: U        SHORT_BINSTRING 'x-cookieM'
-     17: U        SHORT_BINSTRING '5EAIK'
+     17: U        SHORT_BINSTRING 'ESSAD'
      24: U        SHORT_BINSTRING 'x-generator'
      37: q        BINPUT     2
-     39: U        SHORT_BINSTRING 'zodb/py2 (g)'
+     39: U        SHORT_BINSTRING 'zodb/py2 (e)'
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000003 34 sha1:0d5cd01d0b1c8e6f40fdb2e6d417e9f669c884f4
+obj 0000000000000006 34 sha1:27744ea516240e0d00be75f26af9698f842bdda5
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'g2.21'
+     24: U    SHORT_BINSTRING 'e2.21'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbae2e81b5b3 " "
+txn 0285cbae33333400 " "
 user "user2.22"
 description "step 2.22"
 extension
@@ -1755,28 +1790,28 @@ extension
       2: }    EMPTY_DICT
       3: q    BINPUT     1
       5: (    MARK
-      6: U        SHORT_BINSTRING 'x-cookieD'
-     17: U        SHORT_BINSTRING 'MESSA'
+      6: U        SHORT_BINSTRING 'x-cookieH'
+     17: U        SHORT_BINSTRING 'DL5OC'
      24: U        SHORT_BINSTRING 'x-generator'
      37: q        BINPUT     2
-     39: U        SHORT_BINSTRING 'zodb/py2 (c)'
+     39: U        SHORT_BINSTRING 'zodb/py2 (e)'
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000008 34 sha1:5f40b64fc1a997b4426307755b3f01d66710211a
+obj 0000000000000006 34 sha1:a3f303ddd4f2fb9369f6fbbb38ae8030f7f8188d
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'c2.22'
+     24: U    SHORT_BINSTRING 'e2.22'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbae33333400 " "
+txn 0285cbae37e4b24c " "
 user "user2.23"
 description "step 2.23"
 extension
@@ -1784,28 +1819,28 @@ extension
       2: }    EMPTY_DICT
       3: q    BINPUT     1
       5: (    MARK
-      6: U        SHORT_BINSTRING 'x-cookieC'
-     17: U        SHORT_BINSTRING 'PDL5O'
+      6: U        SHORT_BINSTRING 'x-cookieQ'
+     17: U        SHORT_BINSTRING 'PBN2A'
      24: U        SHORT_BINSTRING 'x-generator'
      37: q        BINPUT     2
-     39: U        SHORT_BINSTRING 'zodb/py2 (b)'
+     39: U        SHORT_BINSTRING 'zodb/py2 (d)'
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000004 34 sha1:6acfb712234bb732bd96b893c87ec37cc3c4fe43
+obj 0000000000000002 34 sha1:343bed4b31f4fe69a92ee51d28fd7b9cfd6ecb8b
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'b2.23'
+     24: U    SHORT_BINSTRING 'd2.23'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbae37e4b24c " "
+txn 0285cbae3c963099 " "
 user "user2.24"
 description "step 2.24"
 extension
@@ -1813,28 +1848,28 @@ extension
       2: }    EMPTY_DICT
       3: q    BINPUT     1
       5: (    MARK
-      6: U        SHORT_BINSTRING 'x-cookieA'
-     17: U        SHORT_BINSTRING 'HPBN2'
+      6: U        SHORT_BINSTRING 'x-cookie2'
+     17: U        SHORT_BINSTRING '0GV0I'
      24: U        SHORT_BINSTRING 'x-generator'
      37: q        BINPUT     2
-     39: U        SHORT_BINSTRING 'zodb/py2 (c)'
+     39: U        SHORT_BINSTRING 'zodb/py2 (e)'
      53: u        SETITEMS   (MARK at 5)
      54: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000008 34 sha1:6cb9e4f502834b71b06f3e9cf99deb16dd6f0cfb
+obj 0000000000000006 34 sha1:8804c60dc27b2e2f6908e2a099a5c5d4b5abc843
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'c2.24'
+     24: U    SHORT_BINSTRING 'e2.24'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbae3c963099 " "
+txn 0285cbae4147aee6 " "
 user "root2.0\nYour\nMagesty "
 description "undo 2.0\nmore detailed description\n\nzzz ...\t\t"
 extension
@@ -1842,17 +1877,17 @@ extension
       2: }    EMPTY_DICT
       3: q    BINPUT     1
       5: (    MARK
-      6: U        SHORT_BINSTRING 'x-cookie0'
-     17: U        SHORT_BINSTRING '1M0GV'
+      6: U        SHORT_BINSTRING 'x-cookieM'
+     17: U        SHORT_BINSTRING 'OQO01'
      24: U        SHORT_BINSTRING 'x-generator'
      37: q        BINPUT     2
-     39: U        SHORT_BINSTRING 'zodb/py2 (undo AoXLrjMzNAA=)'
+     39: U        SHORT_BINSTRING 'zodb/py2 (undo AoXLrjfkskw=)'
      69: u        SETITEMS   (MARK at 5)
      70: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000004 from 0285cbae206d3acc
+obj 0000000000000002 from 0285cbae206d3acc
 
-txn 0285cbae4147aee6 " "
+txn 0285cbae45f92d33 " "
 user "root2.1\nYour\nMagesty "
 description "undo 2.1\nmore detailed description\n\nzzz ...\t\t\t"
 extension
@@ -1860,21 +1895,53 @@ extension
       2: }    EMPTY_DICT
       3: q    BINPUT     1
       5: (    MARK
-      6: U        SHORT_BINSTRING 'x-cookie0'
-     17: U        SHORT_BINSTRING '2VOQO'
+      6: U        SHORT_BINSTRING 'x-cookieA'
+     17: U        SHORT_BINSTRING 'VPQ8R'
      24: U        SHORT_BINSTRING 'x-generator'
      37: q        BINPUT     2
-     39: U        SHORT_BINSTRING 'zodb/py2 (undo AoXLrjfkskw=)'
+     39: U        SHORT_BINSTRING 'zodb/py2 (undo AoXLrjyWMJk=)'
      69: u        SETITEMS   (MARK at 5)
      70: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000008 from 0285cbae2e81b5b3
+obj 0000000000000006 from 0285cbae33333400
 
-txn 0285cbae45f92d33 " "
+txn 0285cbae4aaaab80 " "
+user "user"
+description "cyclic reference"
+extension
+      0: \x80 PROTO      2
+      2: }    EMPTY_DICT
+      3: q    BINPUT     1
+      5: (    MARK
+      6: U        SHORT_BINSTRING 'x-generator'
+     19: q        BINPUT     2
+     21: U        SHORT_BINSTRING 'zodb/py2 (cycle)'
+     39: U        SHORT_BINSTRING 'x-cookieG'
+     50: U        SHORT_BINSTRING 'B6FWF'
+     57: u        SETITEMS   (MARK at 5)
+     58: .    STOP
+  highest protocol among opcodes = 2
+obj 0000000000000006 41 sha1:863d327e4b795efff7dff75bb73c0d20ea3981aa
+      0: \x80 PROTO      2
+      2: c    GLOBAL     '__main__ Object'
+     19: q    BINPUT     1
+     21: .    STOP
+  highest protocol among opcodes = 2
+     22: \x80 PROTO      2
+     24: U    SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x06'
+     34: q    BINPUT     2
+     36: h    BINGET     1
+     38: \x86 TUPLE2
+     39: Q    BINPERSID
+     40: .    STOP
+  highest protocol among opcodes = 2
+
+
+txn 0285cbae4f5c29cc " "
 user ""
-description "predelete 2"
+description "predelete 6"
 extension ""
-obj 0000000000000000 213 sha1:193a3d6e70241106bcc22c72857f2b40195b1bc1
+obj 0000000000000000 213 sha1:b44d53e1b6cc465c4ab3ba2a3384a80fbba4eb8a
       0: \x80 PROTO      2
       2: c    GLOBAL     'persistent.mapping PersistentMapping'
      40: q    BINPUT     1
@@ -1896,31 +1963,31 @@ obj 0000000000000000 213 sha1:193a3d6e70241106bcc22c72857f2b40195b1bc1
      94: \x86     TUPLE2
      95: Q        BINPERSID
      96: U        SHORT_BINSTRING 'c'
-     99: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x08'
+     99: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x07'
     109: q        BINPUT     7
     111: h        BINGET     6
     113: \x86     TUPLE2
     114: Q        BINPERSID
     115: U        SHORT_BINSTRING 'b'
-    118: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x04'
+    118: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x08'
     128: q        BINPUT     8
     130: h        BINGET     6
     132: \x86     TUPLE2
     133: Q        BINPERSID
     134: U        SHORT_BINSTRING 'e'
-    137: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\t'
+    137: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\n'
     147: q        BINPUT     9
     149: h        BINGET     6
     151: \x86     TUPLE2
     152: Q        BINPERSID
     153: U        SHORT_BINSTRING 'd'
-    156: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\n'
+    156: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x02'
     166: q        BINPUT     10
     168: h        BINGET     6
     170: \x86     TUPLE2
     171: Q        BINPERSID
     172: U        SHORT_BINSTRING 'g'
-    175: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x03'
+    175: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\t'
     185: q        BINPUT     11
     187: h        BINGET     6
     189: \x86     TUPLE2
@@ -1936,20 +2003,20 @@ obj 0000000000000000 213 sha1:193a3d6e70241106bcc22c72857f2b40195b1bc1
     212: .    STOP
   highest protocol among opcodes = 2
 
-obj 000000000000000a 32 sha1:c9a667705323348a209f8f3b22c1977dbcd3f7e9
+obj 000000000000000a 32 sha1:35a18f6ce20260014618957689b770b74d7b3c78
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'd2*'
+     24: U    SHORT_BINSTRING 'e2*'
      29: q    BINPUT     2
      31: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbae4aaaab80 " "
+txn 0285cbae540da819 " "
 user "root2\nYour\nRoyal\nMagesty' \x00\x01\x02\x03\x04\x05\x06\x07\x08\t\n\x0b\x0c\r\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f"
 description "delete 2\nalpha beta gamma'delta\"lambda\n\nqqq ..."
 extension
@@ -1957,13 +2024,13 @@ extension
       2: }    EMPTY_DICT
       3: q    BINPUT     1
       5: (    MARK
-      6: U        SHORT_BINSTRING 'x-cookieR'
-     17: U        SHORT_BINSTRING 'ZVPQ8'
+      6: U        SHORT_BINSTRING 'x-cookieT'
+     17: U        SHORT_BINSTRING '4WFSD'
      24: U        SHORT_BINSTRING 'x-generator'
      37: q        BINPUT     2
-     39: U        SHORT_BINSTRING 'zodb/py2 (delete 2)'
+     39: U        SHORT_BINSTRING 'zodb/py2 (delete 6)'
      60: u        SETITEMS   (MARK at 5)
      61: .    STOP
   highest protocol among opcodes = 2
-obj 0000000000000002 delete
+obj 0000000000000006 delete
 

zodbtools/test/testdata/1_!zext.zdump.zpickledis.ok

@@ -49,45 +49,48 @@ obj 0000000000000006 34 sha1:0734767857e69ab8bfd0007d4ca3f1a7fd69b677
   highest protocol among opcodes = 2
 
 
-txn 0285cbacb258bf66 "p"
-user "root0.0\nYour\nMagesty "
-description "undo 0.0\nmore detailed description\n\nzzz ..."
+txn 0285cbacb70a3db3 "p"
+user "root0.1\nYour\nMagesty "
+description "undo 0.1\nmore detailed description\n\nzzz ...\t"
 extension ""
-obj 0000000000000005 34 sha1:820cfeef1fc1fc1bda646401c5603fad36c7011e
+obj 0000000000000004 34 sha1:fe21381adc01e51965c3278c6debf52ebd63068c
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'e0.14'
+     24: U    SHORT_BINSTRING 'd0.11'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbacb70a3db3 "p"
-user "root0.1\nYour\nMagesty "
-description "undo 0.1\nmore detailed description\n\nzzz ...\t"
+txn 0285cbacbbbbbc00 "p"
+user "user"
+description "cyclic reference"
 extension ""
-obj 0000000000000004 34 sha1:fe21381adc01e51965c3278c6debf52ebd63068c
+obj 0000000000000002 41 sha1:1e2e3ac81badec749c2082a08d205c06c6bb5119
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'd0.11'
-     31: q    BINPUT     2
-     33: .    STOP
+     24: U    SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x02'
+     34: q    BINPUT     2
+     36: h    BINGET     1
+     38: \x86 TUPLE2
+     39: Q    BINPERSID
+     40: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbacbbbbbc00 "p"
+txn 0285cbacc06d3a4c "p"
 user ""
-description "predelete 2"
+description "predelete 5"
 extension ""
-obj 0000000000000000 194 sha1:5456a4d7bbe20eb26beb84eae76762cd9f4f8c8a
+obj 0000000000000000 194 sha1:4a9e413a4ff168a6a7f84be32b9168364048fd6d
       0: \x80 PROTO      2
       2: c    GLOBAL     'persistent.mapping PersistentMapping'
      40: q    BINPUT     1
@@ -102,7 +105,7 @@ obj 0000000000000000 194 sha1:5456a4d7bbe20eb26beb84eae76762cd9f4f8c8a
      57: q    BINPUT     4
      59: (    MARK
      60: U        SHORT_BINSTRING 'c'
-     63: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x07'
+     63: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x02'
      73: q        BINPUT     5
      75: c        GLOBAL     '__main__ Object'
      92: q        BINPUT     6
@@ -115,7 +118,7 @@ obj 0000000000000000 194 sha1:5456a4d7bbe20eb26beb84eae76762cd9f4f8c8a
     113: \x86     TUPLE2
     114: Q        BINPERSID
     115: U        SHORT_BINSTRING 'e'
-    118: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x05'
+    118: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x07'
     128: q        BINPUT     8
     130: h        BINGET     6
     132: \x86     TUPLE2
@@ -143,54 +146,54 @@ obj 0000000000000000 194 sha1:5456a4d7bbe20eb26beb84eae76762cd9f4f8c8a
     193: .    STOP
   highest protocol among opcodes = 2
 
-obj 0000000000000007 32 sha1:c0517df3bfc49dcda73c2797fb957c92bc651888
+obj 0000000000000007 32 sha1:b9d61167d2388ac320b1bc2940b43e7a8bad46ac
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'c0*'
+     24: U    SHORT_BINSTRING 'e0*'
      29: q    BINPUT     2
      31: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbad02222280 " "
+txn 0285cbad06d3a0cc " "
 user "user1.0"
 description "step 1.0"
 extension ""
-obj 0000000000000004 33 sha1:cb655aa6a738a9855dffeb7584da2df381ab89d6
+obj 0000000000000007 33 sha1:f18e991b87b63cf1f9486d74d70020ff8d573eec
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'd1.0'
+     24: U    SHORT_BINSTRING 'e1.0'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbad06d3a0cc " "
+txn 0285cbad0b851f19 " "
 user "user1.1"
 description "step 1.1"
 extension ""
-obj 0000000000000005 33 sha1:3362a180bda38de9551456e11aba3a50b3ee4063
+obj 0000000000000006 33 sha1:bf4f1be3d63bca5c7dccf98f7660f419597a0f3d
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'e1.1'
+     24: U    SHORT_BINSTRING 'g1.1'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbad0b851f19 " "
+txn 0285cbad10369d66 " "
 user "user1.2"
 description "step 1.2"
 extension ""
@@ -207,113 +210,96 @@ obj 0000000000000006 33 sha1:28e9880fc0f50a9fea5c4a9e861adc1fe44c9f5c
   highest protocol among opcodes = 2
 
 
-txn 0285cbad10369d66 " "
+txn 0285cbad14e81bb3 " "
 user "user1.3"
 description "step 1.3"
 extension ""
-obj 0000000000000006 33 sha1:5fb466e36ea6f847b73ad7976def8ad60e00e766
+obj 0000000000000004 33 sha1:e8796affc44d563a09a2913907f91467a34498fc
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'g1.3'
+     24: U    SHORT_BINSTRING 'd1.3'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbad14e81bb3 " "
+txn 0285cbad19999a00 " "
 user "user1.4"
 description "step 1.4"
 extension ""
-obj 0000000000000004 33 sha1:31a9f07c87da619daa5212fd3c1af57419d07fc3
+obj 0000000000000006 33 sha1:15a38343610d25057cd88521669671350eb0c0a8
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'd1.4'
+     24: U    SHORT_BINSTRING 'g1.4'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbad19999a00 " "
+txn 0285cbad1e4b184c " "
 user "user1.5"
 description "step 1.5"
 extension ""
-obj 0000000000000006 33 sha1:ad1fa70347e93f4e7987bb4702494619db32cb73
+obj 0000000000000003 33 sha1:0adf3b787e6814b6cc073bd51a42c3f18615a674
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'g1.5'
+     24: U    SHORT_BINSTRING 'b1.5'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbad1e4b184c " "
+txn 0285cbad22fc9699 " "
 user "user1.6"
 description "step 1.6"
 extension ""
-obj 0000000000000003 33 sha1:f0d30533c8b386ed571c400c0a37aec4df75fe52
+obj 0000000000000001 33 sha1:4d811fcaaa707127f5f6f49dc368ffd2ebae1018
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'b1.6'
+     24: U    SHORT_BINSTRING 'f1.6'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbad22fc9699 " "
+txn 0285cbad27ae14e6 " "
 user "user1.7"
 description "step 1.7"
 extension ""
-obj 0000000000000001 33 sha1:fee73692c6795a6421978a1ccdca4b61468a487b
+obj 0000000000000004 33 sha1:4c3e1f41eebd1f56c0fef1f609d64e061a137f5a
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'f1.7'
+     24: U    SHORT_BINSTRING 'd1.7'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbad27ae14e6 " "
+txn 0285cbad2c5f9333 " "
 user "user1.8"
 description "step 1.8"
 extension ""
-obj 0000000000000004 33 sha1:e9dc07c0050bf3b9378a1f17d562b8a2423c6076
-      0: \x80 PROTO      2
-      2: c    GLOBAL     '__main__ Object'
-     19: q    BINPUT     1
-     21: .    STOP
-  highest protocol among opcodes = 2
-     22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'd1.8'
-     30: q    BINPUT     2
-     32: .    STOP
-  highest protocol among opcodes = 2
-
-
-txn 0285cbad2c5f9333 " "
-user "user1.9"
-description "step 1.9"
-extension ""
-obj 0000000000000000 213 sha1:f4bcbfda350ec47458539ad8aa8566a89f278015
+obj 0000000000000000 213 sha1:8ccd62e915379b196be62bdb500c4019dfb7825f
       0: \x80 PROTO      2
       2: c    GLOBAL     'persistent.mapping PersistentMapping'
      40: q    BINPUT     1
@@ -335,7 +321,7 @@ obj 0000000000000000 213 sha1:f4bcbfda350ec47458539ad8aa8566a89f278015
      94: \x86     TUPLE2
      95: Q        BINPERSID
      96: U        SHORT_BINSTRING 'c'
-     99: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x07'
+     99: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x02'
     109: q        BINPUT     7
     111: h        BINGET     6
     113: \x86     TUPLE2
@@ -347,7 +333,7 @@ obj 0000000000000000 213 sha1:f4bcbfda350ec47458539ad8aa8566a89f278015
     132: \x86     TUPLE2
     133: Q        BINPERSID
     134: U        SHORT_BINSTRING 'e'
-    137: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x05'
+    137: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x07'
     147: q        BINPUT     9
     149: h        BINGET     6
     151: \x86     TUPLE2
@@ -375,291 +361,328 @@ obj 0000000000000000 213 sha1:f4bcbfda350ec47458539ad8aa8566a89f278015
     212: .    STOP
   highest protocol among opcodes = 2
 
-obj 0000000000000008 33 sha1:9e7210231bc0dd64ef92361d6bc4c9a3f5670aaf
+obj 0000000000000008 33 sha1:7cffb67651540355d8467852ec6cabcb48d964aa
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'a1.9'
+     24: U    SHORT_BINSTRING 'a1.8'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
 txn 0285cbad31111180 " "
+user "user1.9"
+description "step 1.9"
+extension ""
+obj 0000000000000001 33 sha1:c32c4831eabc3a97810c4f925465c6093e4fb716
+      0: \x80 PROTO      2
+      2: c    GLOBAL     '__main__ Object'
+     19: q    BINPUT     1
+     21: .    STOP
+  highest protocol among opcodes = 2
+     22: \x80 PROTO      2
+     24: U    SHORT_BINSTRING 'f1.9'
+     30: q    BINPUT     2
+     32: .    STOP
+  highest protocol among opcodes = 2
+
+
+txn 0285cbad35c28fcc " "
 user "user1.10"
 description "step 1.10"
 extension ""
-obj 0000000000000001 34 sha1:32ad367b3ca4641b070902c7d3073b4fa7e22b85
+obj 0000000000000002 34 sha1:07fe4a745e127abf54f451d41fba5db7bd10ac9d
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'f1.10'
+     24: U    SHORT_BINSTRING 'c1.10'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbad35c28fcc " "
+txn 0285cbad3a740e19 " "
 user "user1.11"
 description "step 1.11"
 extension ""
-obj 0000000000000007 34 sha1:88ab1add11652101077535c03b04e83fe4ddb88b
+obj 0000000000000001 34 sha1:2f0fc397cd9bdceb59cfb7e40b823ae3a81e2f7c
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'c1.11'
+     24: U    SHORT_BINSTRING 'f1.11'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbad3a740e19 " "
+txn 0285cbad3f258c66 " "
 user "user1.12"
 description "step 1.12"
 extension ""
-obj 0000000000000001 34 sha1:ae2ad008499e3ad36f7c7453437c10dafacc687e
+obj 0000000000000007 34 sha1:4808aef147f8ded08ffaae2ce04265506385e7f7
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'f1.12'
+     24: U    SHORT_BINSTRING 'e1.12'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbad3f258c66 " "
+txn 0285cbad43d70ab3 " "
 user "user1.13"
 description "step 1.13"
 extension ""
-obj 0000000000000005 34 sha1:1b5a346d8929e52eb078f442c300d26e125e4200
+obj 0000000000000008 34 sha1:656d65291d6e34225fe2c8213c2241b390e7487a
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'e1.13'
+     24: U    SHORT_BINSTRING 'a1.13'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbad43d70ab3 " "
+txn 0285cbad48888900 " "
 user "user1.14"
 description "step 1.14"
 extension ""
-obj 0000000000000008 34 sha1:2e14c0bd1a82ee7d1ee18d76881221845f47627c
+obj 0000000000000004 34 sha1:87a243d2e9bdd70a84129119894b7d25479f4abc
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'a1.14'
+     24: U    SHORT_BINSTRING 'd1.14'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbad48888900 " "
+txn 0285cbad4d3a074c " "
 user "user1.15"
 description "step 1.15"
 extension ""
-obj 0000000000000004 34 sha1:f136bac1befa0fbd1ebd50218f8d9afe00b9b0a5
+obj 0000000000000006 34 sha1:2e9ebc331bf53c095e9573de64a9b31f2b340b2f
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'd1.15'
+     24: U    SHORT_BINSTRING 'g1.15'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbad4d3a074c " "
+txn 0285cbad51eb8599 " "
 user "user1.16"
 description "step 1.16"
 extension ""
-obj 0000000000000006 34 sha1:778621ce5c5e97b65343b1ab0cc1a3ce5702fbc8
+obj 0000000000000003 34 sha1:86adb5f06801883ba2be7776f68bd8ab46b34dd8
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'g1.16'
+     24: U    SHORT_BINSTRING 'b1.16'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbad51eb8599 " "
+txn 0285cbad569d03e6 " "
 user "user1.17"
 description "step 1.17"
 extension ""
-obj 0000000000000003 34 sha1:647be0dedecdb5b4db6ba09d53be97e1f2c27bb2
+obj 0000000000000002 34 sha1:033ab1c2cfacb42e1db63ec9fac8427c700cc3cb
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'b1.17'
+     24: U    SHORT_BINSTRING 'c1.17'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbad569d03e6 " "
+txn 0285cbad5b4e8233 " "
 user "user1.18"
 description "step 1.18"
 extension ""
-obj 0000000000000007 34 sha1:bfe7a4966f673758259d81429e6e6b3543fbdc4e
+obj 0000000000000006 34 sha1:11f0228fea479a8dacdda2351f2720d005c04b06
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'c1.18'
+     24: U    SHORT_BINSTRING 'g1.18'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbad5b4e8233 " "
+txn 0285cbad60000080 " "
 user "user1.19"
 description "step 1.19"
 extension ""
-obj 0000000000000006 34 sha1:b0b31eb0b48548119153628eb3c6711d959e9f9b
+obj 0000000000000003 34 sha1:6f5ef8a80a64540885791a6b1e2d1a352ee91d1a
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'g1.19'
+     24: U    SHORT_BINSTRING 'b1.19'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbad60000080 " "
+txn 0285cbad64b17ecc " "
 user "user1.20"
 description "step 1.20"
 extension ""
-obj 0000000000000003 34 sha1:884af302035127df026f8b5fcd29711489d8c3e9
+obj 0000000000000004 34 sha1:1c032191dab251d941e739b3703f42ed7e43b246
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'b1.20'
+     24: U    SHORT_BINSTRING 'd1.20'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbad64b17ecc " "
+txn 0285cbad6962fd19 " "
 user "user1.21"
 description "step 1.21"
 extension ""
-obj 0000000000000004 34 sha1:af06091cac7b507337c2876c28d3977b969f4b8a
+obj 0000000000000003 34 sha1:d90118a669a7a9dbe6b779bcc61110df0cc97fd1
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'd1.21'
+     24: U    SHORT_BINSTRING 'b1.21'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbad6962fd19 " "
+txn 0285cbad6e147b66 " "
 user "user1.22"
 description "step 1.22"
 extension ""
-obj 0000000000000003 34 sha1:ca52325c013834a4dd9fc81caca23aef75e31fc0
+obj 0000000000000006 34 sha1:cd7d6434b0aa8290342b60c85d7378cda0d19734
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'b1.22'
+     24: U    SHORT_BINSTRING 'g1.22'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbad6e147b66 " "
+txn 0285cbad72c5f9b3 " "
 user "user1.23"
 description "step 1.23"
 extension ""
-obj 0000000000000006 34 sha1:36b1190c8065ee5db865bf7bb11cfc1b2d1c2120
+obj 0000000000000001 34 sha1:230c0adc97facea312cd09aeb825f9a6c953e029
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'g1.23'
+     24: U    SHORT_BINSTRING 'f1.23'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbad72c5f9b3 " "
+txn 0285cbad77777800 " "
 user "user1.24"
 description "step 1.24"
 extension ""
-obj 0000000000000001 34 sha1:b35a1826cc6cb71b9ddff043f0e8f88b4d90281f
+obj 0000000000000004 34 sha1:ec728760e33cbafcd21496354cbe752995dc02c4
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'f1.24'
+     24: U    SHORT_BINSTRING 'd1.24'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbad77777800 " "
+txn 0285cbad7c28f64c " "
 user "root1.0\nYour\nMagesty "
 description "undo 1.0\nmore detailed description\n\nzzz ...\t"
 extension ""
-obj 0000000000000006 from 0285cbad5b4e8233
+obj 0000000000000001 from 0285cbad3a740e19
 
-txn 0285cbad7c28f64c " "
+txn 0285cbad80da7499 " "
 user "root1.1\nYour\nMagesty "
 description "undo 1.1\nmore detailed description\n\nzzz ...\t\t"
 extension ""
-obj 0000000000000001 from 0285cbad3a740e19
+obj 0000000000000004 from 0285cbad64b17ecc
 
-txn 0285cbad80da7499 " "
+txn 0285cbad858bf2e6 " "
+user "user"
+description "cyclic reference"
+extension ""
+obj 0000000000000008 41 sha1:ecd78bff79e5e10c04d6a14c8277d3fd5baba3a2
+      0: \x80 PROTO      2
+      2: c    GLOBAL     '__main__ Object'
+     19: q    BINPUT     1
+     21: .    STOP
+  highest protocol among opcodes = 2
+     22: \x80 PROTO      2
+     24: U    SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x08'
+     34: q    BINPUT     2
+     36: h    BINGET     1
+     38: \x86 TUPLE2
+     39: Q    BINPERSID
+     40: .    STOP
+  highest protocol among opcodes = 2
+
+
+txn 0285cbad8a3d7133 " "
 user ""
-description "predelete 5"
+description "predelete 3"
 extension ""
-obj 0000000000000000 213 sha1:125bc13199ab5e44db744c520533ead6b0632f00
+obj 0000000000000000 213 sha1:e8e6e66cf82c7cbff72efb7bed28826296e51a01
       0: \x80 PROTO      2
       2: c    GLOBAL     'persistent.mapping PersistentMapping'
      40: q    BINPUT     1
@@ -681,19 +704,19 @@ obj 0000000000000000 213 sha1:125bc13199ab5e44db744c520533ead6b0632f00
      94: \x86     TUPLE2
      95: Q        BINPERSID
      96: U        SHORT_BINSTRING 'c'
-     99: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x07'
+     99: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x02'
     109: q        BINPUT     7
     111: h        BINGET     6
     113: \x86     TUPLE2
     114: Q        BINPERSID
     115: U        SHORT_BINSTRING 'b'
-    118: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x03'
+    118: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\t'
     128: q        BINPUT     8
     130: h        BINGET     6
     132: \x86     TUPLE2
     133: Q        BINPERSID
     134: U        SHORT_BINSTRING 'e'
-    137: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\t'
+    137: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x07'
     147: q        BINPUT     9
     149: h        BINGET     6
     151: \x86     TUPLE2
@@ -721,111 +744,111 @@ obj 0000000000000000 213 sha1:125bc13199ab5e44db744c520533ead6b0632f00
     212: .    STOP
   highest protocol among opcodes = 2
 
-obj 0000000000000009 32 sha1:1a43b55bc4a19245cce9eb5aa5ad411006f06afe
+obj 0000000000000009 32 sha1:94f4c80027cdf77affb7dd9f26b634975b4619e4
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'e1*'
+     24: U    SHORT_BINSTRING 'b1*'
      29: q    BINPUT     2
      31: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbad858bf2e6 " "
+txn 0285cbad8eeeef80 " "
 user "root1\nYour\nRoyal\nMagesty' \x00\x01\x02\x03\x04\x05\x06\x07\x08\t\n\x0b\x0c\r\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f"
 description "delete 1\nalpha beta gamma'delta\"lambda\n\nqqq ..."
 extension ""
-obj 0000000000000005 delete
+obj 0000000000000003 delete
 
-txn 0285cbadc28f5ccc " "
+txn 0285cbadcbf25966 " "
 user "user2.0"
 description "step 2.0"
 extension ""
-obj 0000000000000008 33 sha1:e14542ee70cda44a9c10581119fda69e59122d9a
+obj 0000000000000004 33 sha1:aff1248f33b29d65fe0b038d7dc11db007e2690d
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'a2.0'
+     24: U    SHORT_BINSTRING 'd2.0'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbadc740db19 " "
+txn 0285cbadd0a3d7b3 " "
 user "user2.1"
 description "step 2.1"
 extension ""
-obj 0000000000000007 33 sha1:037832808bec50c372784161a441cf46720ae028
+obj 0000000000000006 33 sha1:2a2f21f6f3480aef6afd1398bec7f6bffa43109c
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'c2.1'
+     24: U    SHORT_BINSTRING 'g2.1'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbadcbf25966 " "
+txn 0285cbadd5555600 " "
 user "user2.2"
 description "step 2.2"
 extension ""
-obj 0000000000000004 33 sha1:c2b3e9c9a079045fd10f1ddfc306b8e7e75877c8
+obj 0000000000000008 33 sha1:07e79c0eb72eea524bbfbce530b0671a4f90f483
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'd2.2'
+     24: U    SHORT_BINSTRING 'a2.2'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbadd0a3d7b3 " "
+txn 0285cbadda06d44c " "
 user "user2.3"
 description "step 2.3"
 extension ""
-obj 0000000000000006 33 sha1:e6236b8f0a4a2201c0c2375a8f360905108eff2d
+obj 0000000000000004 33 sha1:9985268077ca849a615e15ed1b37634875749695
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'g2.3'
+     24: U    SHORT_BINSTRING 'd2.3'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbadd5555600 " "
+txn 0285cbaddeb85299 " "
 user "user2.4"
 description "step 2.4"
 extension ""
-obj 0000000000000008 33 sha1:c6d96f0663023f3d2c45153e80f1d9ac34e58565
+obj 0000000000000007 33 sha1:55a37439e3dc66552d680833af332b8be83bfc2a
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'a2.4'
+     24: U    SHORT_BINSTRING 'e2.4'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbadda06d44c " "
+txn 0285cbade369d0e6 " "
 user "user2.5"
 description "step 2.5"
 extension ""
@@ -842,24 +865,24 @@ obj 0000000000000004 33 sha1:2e472bec634f703fc24e5192114b0c61364d9273
   highest protocol among opcodes = 2
 
 
-txn 0285cbaddeb85299 " "
+txn 0285cbade81b4f33 " "
 user "user2.6"
 description "step 2.6"
 extension ""
-obj 0000000000000009 33 sha1:77b65f4da784e13c772516f8b64c9afa3a539718
+obj 0000000000000001 33 sha1:e0148787fb3ffe52ef3ba85ad82b6b8afa47e20f
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'e2.6'
+     24: U    SHORT_BINSTRING 'f2.6'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbade369d0e6 " "
+txn 0285cbadeccccd80 " "
 user "user2.7"
 description "step 2.7"
 extension ""
@@ -876,79 +899,79 @@ obj 0000000000000004 33 sha1:9472357211e402a8dfcda8b72f7ef98c2b8d8b20
   highest protocol among opcodes = 2
 
 
-txn 0285cbade81b4f33 " "
+txn 0285cbadf17e4bcc " "
 user "user2.8"
 description "step 2.8"
 extension ""
-obj 0000000000000001 33 sha1:f2a087272b15748e83ccd0da151e6b780b5e84cf
+obj 0000000000000006 33 sha1:d57709ac596de41959e36e1dd6902a853213267e
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'f2.8'
+     24: U    SHORT_BINSTRING 'g2.8'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbadeccccd80 " "
+txn 0285cbadf62fca19 " "
 user "user2.9"
 description "step 2.9"
 extension ""
-obj 0000000000000004 33 sha1:131b4a39325003afe371ebb5ee24a5bb360fdc73
+obj 0000000000000007 33 sha1:f1d87ba386f57291ecc925020a05df06caedb278
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'd2.9'
+     24: U    SHORT_BINSTRING 'e2.9'
      30: q    BINPUT     2
      32: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbadf17e4bcc " "
+txn 0285cbadfae14866 " "
 user "user2.10"
 description "step 2.10"
 extension ""
-obj 0000000000000006 34 sha1:d24bd1f8a061f39190aae0e7a96d711617591e01
+obj 0000000000000007 34 sha1:5118b5ada1ab6ce6852eef392212ea9300ac6f06
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'g2.10'
+     24: U    SHORT_BINSTRING 'e2.10'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbadf62fca19 " "
+txn 0285cbadff92c6b3 " "
 user "user2.11"
 description "step 2.11"
 extension ""
-obj 0000000000000009 34 sha1:a37845561ff3d44ed0d6fb5b6369e5531c9586c4
+obj 0000000000000004 34 sha1:14e8b27b3bc8bf5b4d86ca162cc1c912a29a1c05
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'e2.11'
+     24: U    SHORT_BINSTRING 'd2.11'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbadfae14866 " "
+txn 0285cbae04444500 " "
 user "user2.12"
 description "step 2.12"
 extension ""
-obj 0000000000000009 34 sha1:60c6854b7737f5bbc7569c8b6a694910ed370ccc
+obj 0000000000000007 34 sha1:60c6854b7737f5bbc7569c8b6a694910ed370ccc
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
@@ -961,28 +984,28 @@ obj 0000000000000009 34 sha1:60c6854b7737f5bbc7569c8b6a694910ed370ccc
   highest protocol among opcodes = 2
 
 
-txn 0285cbadff92c6b3 " "
+txn 0285cbae08f5c34c " "
 user "user2.13"
 description "step 2.13"
 extension ""
-obj 0000000000000004 34 sha1:4b28f9e97ff4f61f3dfba30b9f7aceb4913215ce
+obj 0000000000000002 34 sha1:5d89801d288c5238f605784e7c71b2d61598d362
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'd2.13'
+     24: U    SHORT_BINSTRING 'c2.13'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbae04444500 " "
+txn 0285cbae0da74199 " "
 user "user2.14"
 description "step 2.14"
 extension ""
-obj 0000000000000009 34 sha1:0a27d685d77313b1a2b7c3478888a98798847077
+obj 0000000000000007 34 sha1:0a27d685d77313b1a2b7c3478888a98798847077
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
@@ -995,11 +1018,11 @@ obj 0000000000000009 34 sha1:0a27d685d77313b1a2b7c3478888a98798847077
   highest protocol among opcodes = 2
 
 
-txn 0285cbae08f5c34c " "
+txn 0285cbae1258bfe6 " "
 user "user2.15"
 description "step 2.15"
 extension ""
-obj 0000000000000007 34 sha1:ae3975f91e13b4ec60e6810006be027149642926
+obj 0000000000000002 34 sha1:ae3975f91e13b4ec60e6810006be027149642926
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
@@ -1012,176 +1035,196 @@ obj 0000000000000007 34 sha1:ae3975f91e13b4ec60e6810006be027149642926
   highest protocol among opcodes = 2
 
 
-txn 0285cbae0da74199 " "
+txn 0285cbae170a3e33 " "
 user "user2.16"
 description "step 2.16"
 extension ""
-obj 0000000000000009 34 sha1:21c9675d1a7c6152bbd8d5d7102a0ba926cd6325
+obj 0000000000000009 34 sha1:0f253572ebd02bdd419b287ac75113bc8213ef83
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'e2.16'
+     24: U    SHORT_BINSTRING 'b2.16'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbae1258bfe6 " "
+txn 0285cbae1bbbbc80 " "
 user "user2.17"
 description "step 2.17"
 extension ""
-obj 0000000000000007 34 sha1:2840f7eadf2b100a429e5a358f9656985827612b
+obj 0000000000000009 34 sha1:9961f82b3f01204f80efbb3b62a2b98d9d3202fa
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'c2.17'
+     24: U    SHORT_BINSTRING 'b2.17'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbae170a3e33 " "
+txn 0285cbae206d3acc " "
 user "user2.18"
 description "step 2.18"
 extension ""
-obj 0000000000000003 34 sha1:428f7ab13e02b7facbd1e4ddbcc1833ace6250d0
+obj 0000000000000007 34 sha1:00cce52a596916011d8935c4e53dcb04510af2d9
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'b2.18'
+     24: U    SHORT_BINSTRING 'e2.18'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbae1bbbbc80 " "
+txn 0285cbae251eb919 " "
 user "user2.19"
 description "step 2.19"
 extension ""
-obj 0000000000000003 34 sha1:c1b57432c9e2fad36fe4a1efaa0445851865b775
+obj 0000000000000007 34 sha1:523ec17c6d74016e3464d52bb7c7b7baa4b82a20
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'b2.19'
+     24: U    SHORT_BINSTRING 'e2.19'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbae206d3acc " "
+txn 0285cbae29d03766 " "
 user "user2.20"
 description "step 2.20"
 extension ""
-obj 0000000000000009 34 sha1:5f1b9fc7ba1147cdfbe3a0a74f988bf355cfc3b4
+obj 0000000000000004 34 sha1:9cf3a2031b4e9af93e7fd40e58dbceedc753b7d6
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'e2.20'
+     24: U    SHORT_BINSTRING 'd2.20'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbae251eb919 " "
+txn 0285cbae2e81b5b3 " "
 user "user2.21"
 description "step 2.21"
 extension ""
-obj 0000000000000009 34 sha1:27744ea516240e0d00be75f26af9698f842bdda5
+obj 0000000000000008 34 sha1:330a069412b6cfb00a43da001b600b7f6b2380e6
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'e2.21'
+     24: U    SHORT_BINSTRING 'a2.21'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbae29d03766 " "
+txn 0285cbae33333400 " "
 user "user2.22"
 description "step 2.22"
 extension ""
-obj 0000000000000004 34 sha1:f3c8fd6739f600592fdaaf3ef1f7dbf788306cfc
+obj 0000000000000001 34 sha1:bf2d0d8f4cd81e1592001eb3c265a22894cdb51b
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'd2.22'
+     24: U    SHORT_BINSTRING 'f2.22'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbae2e81b5b3 " "
+txn 0285cbae37e4b24c " "
 user "user2.23"
 description "step 2.23"
 extension ""
-obj 0000000000000008 34 sha1:6cc69da894b91f857e89146dcd6e3edd08eea0ed
+obj 0000000000000006 34 sha1:c47e0f1415e14f41016809ac3a4323745ad79170
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'a2.23'
+     24: U    SHORT_BINSTRING 'g2.23'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbae33333400 " "
+txn 0285cbae3c963099 " "
 user "user2.24"
 description "step 2.24"
 extension ""
-obj 0000000000000001 34 sha1:49a11733c8365f1adbc76bff48a1d3b689618556
+obj 0000000000000006 34 sha1:2030a0ccc56595b70aac033e70c899060dbfb0f9
       0: \x80 PROTO      2
       2: c    GLOBAL     '__main__ Object'
      19: q    BINPUT     1
      21: .    STOP
   highest protocol among opcodes = 2
      22: \x80 PROTO      2
-     24: U    SHORT_BINSTRING 'f2.24'
+     24: U    SHORT_BINSTRING 'g2.24'
      31: q    BINPUT     2
      33: .    STOP
   highest protocol among opcodes = 2
 
 
-txn 0285cbae37e4b24c " "
+txn 0285cbae45f92d33 " "
 user "root2.0\nYour\nMagesty "
 description "undo 2.0\nmore detailed description\n\nzzz ...\t\t"
 extension ""
-obj 0000000000000008 from 0285cbadd5555600
+obj 0000000000000001 from 0285cbade81b4f33
 
-txn 0285cbae3c963099 " "
+txn 0285cbae4aaaab80 " "
 user "root2.1\nYour\nMagesty "
 description "undo 2.1\nmore detailed description\n\nzzz ...\t\t\t"
 extension ""
-obj 0000000000000001 from 0285cbade81b4f33
+obj 0000000000000006 from 0285cbae37e4b24c
+
+txn 0285cbae4f5c29cc " "
+user "user"
+description "cyclic reference"
+extension ""
+obj 0000000000000006 41 sha1:863d327e4b795efff7dff75bb73c0d20ea3981aa
+      0: \x80 PROTO      2
+      2: c    GLOBAL     '__main__ Object'
+     19: q    BINPUT     1
+     21: .    STOP
+  highest protocol among opcodes = 2
+     22: \x80 PROTO      2
+     24: U    SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x06'
+     34: q    BINPUT     2
+     36: h    BINGET     1
+     38: \x86 TUPLE2
+     39: Q    BINPERSID
+     40: .    STOP
+  highest protocol among opcodes = 2
+
 
-txn 0285cbae4147aee6 " "
+txn 0285cbae540da819 " "
 user ""
 description "predelete 1"
 extension ""
-obj 0000000000000000 213 sha1:cf71305f1094cda7b0fef253960035bb6e5b48b4
+obj 0000000000000000 213 sha1:ae6936a4e7c9f3f748d8ecf28186e259897651dd
       0: \x80 PROTO      2
       2: c    GLOBAL     'persistent.mapping PersistentMapping'
      40: q    BINPUT     1
@@ -1203,19 +1246,19 @@ obj 0000000000000000 213 sha1:cf71305f1094cda7b0fef253960035bb6e5b48b4
      94: \x86     TUPLE2
      95: Q        BINPERSID
      96: U        SHORT_BINSTRING 'c'
-     99: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x07'
+     99: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x02'
     109: q        BINPUT     7
     111: h        BINGET     6
     113: \x86     TUPLE2
     114: Q        BINPERSID
     115: U        SHORT_BINSTRING 'b'
-    118: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x03'
+    118: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\t'
     128: q        BINPUT     8
     130: h        BINGET     6
     132: \x86     TUPLE2
     133: Q        BINPERSID
     134: U        SHORT_BINSTRING 'e'
-    137: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\t'
+    137: U        SHORT_BINSTRING '\x00\x00\x00\x00\x00\x00\x00\x07'
     147: q        BINPUT     9
     149: h        BINGET     6
     151: \x86     TUPLE2
@@ -1256,7 +1299,7 @@ obj 000000000000000a 32 sha1:da5c7f574b5e6a64d0d58314a6939ef761266d41
   highest protocol among opcodes = 2
 
 
-txn 0285cbae45f92d33 " "
+txn 0285cbae58bf2666 " "
 user "root2\nYour\nRoyal\nMagesty' \x00\x01\x02\x03\x04\x05\x06\x07\x08\t\n\x0b\x0c\r\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f"
 description "delete 2\nalpha beta gamma'delta\"lambda\n\nqqq ..."
 extension ""

zodbtools/zodbdump.py

 # -*- coding: utf-8 -*-
-# Copyright (C) 2016-2022  Nexedi SA and Contributors.
+# Copyright (C) 2016-2024  Nexedi SA and Contributors.
 #                          Kirill Smelkov <kirr@nexedi.com>
 #                          Jérome Perrin <jerome@nexedi.com>
 #
@@ -161,10 +161,12 @@ def zodbdump(stor, tidmin, tidmax, hashonly=False, pretty='raw', out=asbinstream
                         out.write(obj.data)
                     elif pretty == 'zpickledis':
                         # https://github.com/zopefoundation/ZODB/blob/5.6.0-55-g1226c9d35/src/ZODB/serialize.py#L24-L29
+                        # https://github.com/zopefoundation/ZODB/blob/5.8.1-0-g72cebe6bc/src/ZODB/serialize.py#L436-L443
                         dataf = BytesIO(obj.data)
                         disf  = StringIO()
-                        pickletools.dis(dataf, disf) # class
-                        pickletools.dis(dataf, disf) # state
+                        memo = {} # memo is shared in between class and state
+                        pickletools.dis(dataf, disf, memo) # class
+                        pickletools.dis(dataf, disf, memo) # state
                         out.write(b(indent(disf.getvalue(), "  ")))
                         extra = dataf.read()
                         if len(extra) > 0: