Collections preview fails in python 3

[pbauer]

The preview of collections fails since plone.app.contentlisting cannot adapt lists to IContentListingObject even though list is registered like this:

  <adapter
      factory=".contentlisting.ContentListing"
      for="list"
      />

The method ContentListing.__getitem__ is actually called in a template and the item in question is a list.

[12]   /Users/pbauer/workspace/plip/src/plone.app.querystring/plone/app/querystring/querybuilder.py(112)html_results()
-> )(**options)
[13]   /Users/pbauer/workspace/plip/src/plone.app.querystring/plone/app/querystring/querybuilder.py(38)__call__()
-> return self.index(**kw)
[14]   /Users/pbauer/workspace/plip/src/Zope/src/Products/Five/browser/pagetemplatefile.py(125)__call__()
-> return self.__func__(__self__, *args, **kw)
[15]   /Users/pbauer/workspace/plip/src/Zope/src/Products/Five/browser/pagetemplatefile.py(60)__call__()
-> sourceAnnotations=getattr(debug_flags, 'sourceAnnotations', 0),
[16]   /Users/pbauer/.cache/buildout/eggs/zope.pagetemplate-4.3.0-py3.6.egg/zope/pagetemplate/pagetemplate.py(134)pt_render()
-> strictinsert=0, sourceAnnotations=sourceAnnotations
[17]   /Users/pbauer/workspace/plip/src/Zope/src/Products/PageTemplates/engine.py(85)__call__()
-> return self.template.render(**kwargs)
[18]   /Users/pbauer/.cache/buildout/eggs/z3c.pt-3.1.0-py3.6.egg/z3c/pt/pagetemplate.py(158)render()
-> return base_renderer(**context)
[19]   /Users/pbauer/workspace/plip/src/chameleon/src/chameleon/zpt/template.py(297)render()
-> return super(PageTemplate, self).render(**_kw)
[20]   /Users/pbauer/workspace/plip/src/chameleon/src/chameleon/template.py(171)render()
-> self._render(stream, econtext, rcontext)
[21]   /Users/pbauer/workspace/plip/84d83f2d4816870e860f7cdc1d8117a6.py(128)render()
[22] > /Users/pbauer/workspace/plip/src/plone.app.contentlisting/plone/app/contentlisting/contentlisting.py(30)__getitem__()
-> return IContentListingObject(self._basesequence[index])
(Pdb++) n
TypeError: ('Could not adapt', [<Products.ZCatalog.Catalog.Catalog.useBrains.<locals>.mybrains object at 0x109bb3ea0>, <Products.ZCatalog.Catalog.Catalog.useBrains.<locals>.mybrains object at 0x109bb32d0>, <Products.ZCatalog.Catalog.Catalog.useBrains.<locals>.mybrains object at 0x109bb3438>], <InterfaceClass plone.app.contentlisting.interfaces.IContentListingObject>)
(Pdb++) type(self._basesequence[index])
<class 'list'>

[pbauer]

Exposed in ./bin/test -s plone.portlet.collection -t test_exclude_context

[davisagli]

Addressed in plone/plone.app.contentlisting#28