[#1419] Happens with 0.60 too, is due to standard_error_message

Name: '#1419 ZWiki-unstable: Adding pages is impossible when "Anonymous" has no view access' => '#1419 Adding pages is impossible when "Anonymous" has no view access' 

To specify this: It happens when trying to add wiki pages by going to !example.org/wiki/NonexistingPage. Normally you would get the "this page doesn't exist, do you want to create it or search for it" page, but that tries to access stuff (like objectValues) that is secured by the "Access contents information" permission (but similar erros if "Access contents information" is "on" for anonymous and "View" is "off" for anonymous).

The problem is basically that standard_error_message is always executed as the anonymous user. We have another problem with this: The button for "create page" appears even if the visitor doesn't have permission to create pages.

One idea for fixing this would be to go away from standard_error_message for this functionality, instead use a __before_publishing_traverse__ hook to identify non-existing pages.

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