Rewrite og_menu_form_node_form_alter()

I will need to review this thoroughly

One a sidenote, check the comments/discussion in #1847110: Menu affiliation lost when editing a node in a group, improve menu settings on administer node type form.

Testing the patch
can't get it to work the way it should.

I created a normal user and made him member of the group.
I gave normal members the "administer menu" permission (on group level)

Normally I would expect then, if I add a node to the group with this user, I would see the menu.
In ideal case, the user is only possible to add pages linked to groups he has access to.
he would use the link node/add/group-page?og_group_ref=4 (in my case)
In node_prepare we can already provide the correct menu data. This does not seem to happen.

I retried with admin. Same thing, menu selection does not show up at all.

Tried to see what happens in the code.
You lost me around

      if (!empty($ids) && empty($groups[$field['settings']['target_type']])) {
        $groups[$field['settings']['target_type']] = array_keys($ids);
      }

$ids is an array

Array
(
    [group] => Array
        (
            [4] => MyGroupName
        )

)

if i'm gonna array_keys that, i'll array(0 => 'group'); and not the group id's at all..

Help is welcome if I'm doing something wrong, but I can't commit this if I even can't get the basic functionality to work.

 Drupal core       7.18     7.18     Up to date                               
 Chaos tool suite  7.x-1.2  7.x-1.2  Up to date                                                                                                
 Devel             7.x-1.3  7.x-1.3  Up to date                               
 Entity API        7.x-1.0  7.x-1.0  Up to date                               
 Entity reference  7.x-1.0  7.x-1.0  Up to date                               
 Entityreference   7.x-1.1  7.x-1.1  Up to date                               
 prepopulate                                                                                              
 Organic groups    7.x-2.0  7.x-2.0  Up to date                               
                   -rc1     -rc1                                              
 OG Extras         7.x-1.1  7.x-1.1  Up to date                               
 Views             7.x-3.5  7.x-3.5  Up to date                               
 Views Bulk        7.x-3.1  7.x-3.1  Up to date                               
 Operations (VBO)             

If you are on #drupal IRC you may be able to contact me more directly

Committed!

Thanks for your hard work.

Next up:
In #3 you say:

I don't suffer from #1847110: Menu affiliation lost when editing a node in a group after applying my patch. I had to rewrite parts of og_menu_node_prepare(), this is a major (good :) patch.

Actually, I just tested. Menu _IS_ lost under the conditions mentioned in #1847110: Menu affiliation lost when editing a node in a group, improve menu settings on administer node type form.
I renamed that issue and ongoing development will happen there.