Comment 11 for bug 1034180

Reviewed: https://reviews.mahara.org/2556
Committed: http://gitorious.org/mahara/mahara/commit/79a810210bfdf89a466876fdf8ac54354f73b73b
Submitter: Son Nguyen (<email address hidden>)
Branch: 1.7_STABLE

commit 79a810210bfdf89a466876fdf8ac54354f73b73b
Author: Hugh Davenport <email address hidden>
Date: Wed Aug 15 12:07:58 2012 +1200

Fix permissions of group area (Bug #1034180)

A user should not be able to view/publish an artefact if
- they don't have view/publish permission of that artefact
- they don't have view permission of all parents of that artefact

A user should not be able to edit an artefact if
- they don't have edit permission of that artefact
- they don't have edit permission of the immediate parent of that artefact
- they don't have view permission of any parents below the immediate

This is similar to the UNIX permissions, you shouldn't be able to view
a directory unless all directories below have read (r) and executeable (x)
bits set. The same for editing, you need write (w) permissions of the
immediate parent, and rx for all parents.

In Mahara, there are no executeable bits, but it can be assumed
that view is basically the same as rw for container artefacts, and the same
as r for non container artefacts.

Change-Id: I4f84aca05dd08d02b05fbe084e4724f78c8681a0
Signed-off-by: Hugh Davenport <email address hidden>