Menu item of current node not given active trail when viewing the published revision

I came across this issue when doing a piece of work for a client that attempts to display revision pages as if they were the node page. One issue I had was getting menu blocks (using the menu_block module) to display on the revision pages. I managed to get it working with a bit of trickery, but I kept having an issue where the menu block would not display when viewing the revision that was currently published, but would display on any other revision page (quite counter-intuitive right?). Today I've had some time to debug into this and it's lead me to an interesting discovery:

Basically what I noticed was that the menu item did not have active_trail set to TRUE when returned from menu_tree_page_data(). I tracked this down to the fact that menu_link_get_preferred() was returning the menu item from the Navigation menu rather than from Main menu (again very weird). Debugging further into this function, I noticed that the $preferred_links array did not have the main-menu menu item in it, hence why it wasn't being returned and why the active trail wasn't being set (since menu_link_get_preferred() was returning FALSE which is what causes active_trail to be empty - you can see this at line 1261 of includes/menu.inc).

The only way the main-menu item could be excluded from the $preferred_links array is on line 2517 of includes/menu.inc where after _menu_translate() is run over the $candidate_item the access key is set to false (just a note on both published revision pages and non-published revision pages at this point all variables hold the same values - $path_candidates, $menu_names).

So, inside _menu_translate the _menu_check_access function is called, which then calls whatever the access_callback is that is defined on the router item. In this case it's _revisioning_view_edit_access_callback(). Maybe this is where things are going wrong, because what is actually denying access and causing this whole issue is the following conditional:

    if ($load_op == REVISIONING_LOAD_CURRENT && $vid == $node->current_revision_id) {
      // Suppress 'View current' and 'Edit current' tabs when viewing current.
      return FALSE;
    }

On both the published revision page and any other revision page of a node, the $load_op is 0 (i.e REVISIONING_LOAD_CURRENT), for the non published revisions all of these conditionals fail so it falls through to the final return value of _revisioning_access_node_revision() but for the published revision, the above conditional evaluates to TRUE and the main-menu item is denied access.

Here's some screenshots to show what's going on now:

Published revision:

Unpublished revision:

I don't think this conditional is the only thing that's causing issues, if I simply change it to return TRUE, the breadcrumbs are correctly fixed but the menu item is not marked as active so the child is not shown in the left hand navigation. Nevermind, this was a caching issue, after clearing cache the trial showed correctly :)

I'm hoping someone else has more ideas about what else could be going on and potential fixes! Cheers