Traversals past pages declared with __call__ attribute generate error 500s

[Christian Reis]

If you traverse past pages declared using the __call__ attribute, you hit a 500 error. For instance, the IPerson rdf is declared like this:

  <browser:page
      for="canonical.launchpad.interfaces.IPerson"
      name="+rdf"
      lp:url="/person/$Person.name/+rdf"
      permission="zope.Public"
      class="canonical.launchpad.browser.PersonRdfView"
      attribute="__call__"
      />

If you visit https://launchpad.net/people/kiko/+rdf/foobies you get a System Error instead of a good ole 404. The reason being:

    * Module zope.app.publication.publicationtraverse, line 51, in traverseName
      ob2 = ob.publishTraverse(request, nm)
    * Module zope.app.publisher.browser.viewmeta, line 437, in publishTraverse
      raise NotFoundError(self, name, request)

NotFoundError: (<zope.app.publisher.browser.viewmeta.PersonRdfView object at 0x2aa198d950>, u'foobies', <zope.publisher.browser.BrowserRequest instance URL=https://launchpad.net/people/kiko/+rdf/foobies>)

I think NotFoundError is not the right thing to raise there, and that's the source of the bug, but Steve's the man.

[Stuart Bishop (stub)]

The __call__ should catch the expected exception and return None rather than NotFoundError

[Stuart Bishop (stub)]

Ignore me - I'm describing a different bug

[Steve Alexander (stevea)]

This traverser is presentation code talking directly to the publication, so it should be raising NotFound, the publisher-level exception, or the publisher should be expecting a NotFoundError, and itself raising NotFound. It's a zope3 upstream issue, but we can also fix this locally in launchpad.

[Dafydd Harries (daf)]

Found this status note which I think should be a comment:

"Look at the xx-notfound-traversals test for some commented out tests that fail because of this."

[Christian Reis (kiko)]

This was fixed in the Zope3.2 update. I'm updating the tests to ensure it stays fixed.