Iterate over multilink items if they labelprop is accessible to the

user.

See: https://sourceforge.net/p/roundup/mailman/message/35763294/
[Roundup-devel] I can see nosy but not repeat over items

Basically using tal:repeat uses the viewableGenerator() method in the
templating.py MultilinkHTMLProperty. This Generator verifies that the
user has access to the item referenced in the multilink. However this
leads to the odd condition that:

  all users in the nosy list of an issue are displayed with their
     usernames then looking at issue3 if the user can see the nosy
     property of issue3.

  trying to tal:repeat using the elements of the nosy list in issue3
     fails if the user doesn't have access to the user class. The
     user's ability to access the mutlilink property doesn't matter.

This wierdness was fixed by changing the viewableGenerator to check
for View access to the label property for the class (user in the case
above).

Author: rouilj

roundup/cgi/templating.py

@@ -2275,7 +2275,9 @@ def viewableGenerator(self, values):
         classname = self._prop.classname
         if check('Web Access', userid):
             for value in values:
-                if check('View', userid, classname, itemid=value):
+                if check('View', userid, classname,
+                         itemid=value,
+                         property=self._db.getclass(classname).labelprop(default_to_id=1)):
                     yield HTMLItem(self._client, classname, value)
 
     def __iter__(self):