OFS.SimpleItem initialization problem: infinite loop

[Jean-François Doyon]

This is a Zope core bug discovered while doing a custom CMF content type.

I have a class that subclasses Product.CMFDefault.File (which eventually leads to OFS.SimpleItem).
This class overloads __init__ with a dumb 2 line one.

When migrating from 2.6.3 to 2.7, the said CMF content type can't be viewed, showing the error:

>Zope Error
>Zope has encountered an error while publishing this resource.
>
>Error Type: RuntimeError
>Error Value: maximum recursion depth exceeded
> ...
>Module ZPublisher.Publish, line 94, in publish
>Module Zope.App.startup, line 257, in recordMetaData
>Module OFS.SimpleItem, line 333, in getPhysicalPath
>Module OFS.SimpleItem, line 76, in
>Module OFS.SimpleItem, line 310, in getId
>Module OFS.SimpleItem, line 76, in
>Module OFS.SimpleItem, line 310, in getId
>Module OFS.SimpleItem, line 76, in
>Module OFS.SimpleItem, line 310, in getId
> ...

An infinite loop !!

From Dieter:

>This is a bug in "OFS.SimpleItem.Item_w__name__".
>
> In its base class, "__name__" is defined as
> "ComputedAttribute(lambda self: self.getId())"
> and it defines "getId()" to return "self.__name__".
> Apparently, this is an infinite recursion.
>
>Please file a bug report to "http://www.zope.org/Collectors/Zope".
>
>You can fix this problem by giving "Item_w__name__" a default
>class level attribute or "__name__ = ''".
>
>You can work around the bug by assigning an "id" for your
>object with its "_setId" method (this overrides "__name__").

In my case, after tracking this down, I decided that I really shouldn't have overloaded the __init__ since I didn't need to (I tend to do it out of habbit), so I removed it from my class, and re-created the instances (I only had a few).

Thanks,
J.F.

[João Marcus Christ (joaoma)]

This breaks FileSystemStorage, so a fix for this seems to be important

Replacing:
self.__name__
with:
self.id

seems to fix it

[João Marcus Christ (joaoma)]

Sorry, that doesn't fix it! Breaks ZMI

[Tres Seaver (tseaver)]

Using '_setId' is the standard protocol for assigning a SimpleItem's __name__ / ID.

I'm fine with seeing a class default for '__name__', but only if the patch adds a test
which demonstrates the problem, i.e. fails without the default.

[Colin Watson (cjwatson)]

The zope2 project on Launchpad has been archived at the request of the Zope developers (see https://answers.launchpad.net/launchpad/+question/683589 and https://answers.launchpad.net/launchpad/+question/685285). If this bug is still relevant, please refile it at https://github.com/zopefoundation/zope2.