[#1419 ZWiki-unstable: Adding pages is impossible when "Anonymous" has no view access]

When the "Anonymous" role doesn't have view access to the wiki, trying to
access a non-existing page results in an error instead of the page adding
template.  A traceback obtained from a console follows
::
    Traceback (most recent call last):
      File "/usr/lib/zope2.9/lib/python/OFS/SimpleItem.py", line 221, in raise_standardErrorMessage
        v = s(client, REQUEST, **kwargs)
      File "/usr/lib/zope2.9/lib/python/OFS/DTMLMethod.py", line 145, in __call__
        r=apply(HTML.__call__, (self, client, REQUEST), kw)
      File "/usr/lib/zope2.9/lib/python/DocumentTemplate/DT_String.py", line 476, in __call__
        try: result = render_blocks(self._v_blocks, md)
      File "/usr/lib/zope2.9/lib/python/DocumentTemplate/DT_Let.py", line 75, in render
        else: d[name]=expr(md)
      File "/usr/lib/zope2.9/lib/python/DocumentTemplate/DT_Util.py", line 190, in eval
        d[name] = md.getitem(name, 0)
    Unauthorized: You are not allowed to access 'objectValues' in this context


--
forwarded from http://zwiki.org/1419ZWikiUnstableAddingPagesIsImpossibleWhenAnonymousHasNoViewAccess#[email protected]