[ZODB-Dev] zc.zodbdgc bug - undefined variable

[Jim Fulton]

On Fri, Aug 5, 2011 at 1:55 PM, Hanno Schlichting <hanno at hannosch.eu> wrote:
> On Mon, Aug 1, 2011 at 6:26 PM, Sylvain Viollon <sylvain at infrae.com> wrote:
>>  However, if I run multi-check-gc, I get a Python error:
>>
>> Traceback (most recent call last):
>>  File "./bin/multi-zodb-gc", line 210, in <module>
>>    zc.zodbdgc.gc_command()
>>  File "/Users/sylvain/Documents/debug-eggs/zc.zodbdgc-0.6.0-py2.7.egg/zc/zodbdgc/__init__.py", line 99, in gc_command
>>    untransform=untransform, ptid=ptid)
>>  File "/Users/sylvain/Documents/debug-eggs/zc.zodbdgc-0.6.0-py2.7.egg/zc/zodbdgc/__init__.py", line 105, in gc
>>    return gc_(close, conf, days, ignore, conf2, fs, untransform, ptid)
>>  File "/Users/sylvain/Documents/debug-eggs/zc.zodbdgc-0.6.0-py2.7.egg/zc/zodbdgc/__init__.py", line 220, in gc_
>>    getrefs(data, name, ignore))
>>  File "/Users/sylvain/Documents/debug-eggs/zc.zodbdgc-0.6.0-py2.7.egg/zc/zodbdgc/__init__.py", line 398, in insert
>>    tid = max(tid, oldtid)
>> NameError: global name 'oldtid' is not defined
>>
>>  Which is true, oldtid is not defined anywhere in this Python module.
>
> Indeed, in current trunk oldtid is used on line 398 and 400. Looking
> at the code I cannot tell if it's safe to just remove that code.

It is not. The bug is on line 395.  It should be:

            oldtid = f.read(8)

Of course, this needs to be verified with a test.

This seems to be a (obviously untested) case where
there are multiple records of a garbage object.  I'll have to
ponder how this could actually happen.

Jim

-- 
Jim Fulton
http://www.linkedin.com/in/jimfulton