Feature NOT marked as Overridden when changes only add arrays that contain values that evaluate to FALSE

A Feature is NOT marked as Overridden when the changes to code only add arrays that contain values that evaluate to FALSE. I encountered this specifically with field_bundle_settings_node__NODE_TYPE where the Feature was adding display settings to hide a new extra field on a particular view mode. This adds a section to the variable which looks like:

      // ...
      'display' => array(
        // This is the bit added.
        'field_name' => array(
          'default' => array(
            'weight' => '0',
            'visible' => FALSE,
          ),
        ),
      // ...

However, it possible to reproduce with a reduced set of steps:

1. Install Drupal 7.38, Features 2.6 and Strongarm 2.0
2. Run this Drush command to set a variable with an array that contains other arrays:
   

   drush php-eval 'variable_set("features_testing", array("key" => array("stuff" => array())));'
   

3. Create a new Feature which contains the 'features_testing' variable
4. Enable the new module
5. Edit the MODULE.strongarm.inc and add a new array under "key" that's a sibling to "stuff", which contains all values that evaluate to FALSE. So, for example this what it looked like originally:
   

     $strongarm = new stdClass();
     $strongarm->disabled = FALSE; /* Edit this to true to make a default strongarm disabled initially */
     $strongarm->api_version = 1;
     $strongarm->name = 'features_testing';
     $strongarm->value = array(
       'key' => array(
         'stuff' => array(),
       ),
     );
     $export['features_testing'] = $strongarm;
   

   And then change it to:

     $strongarm = new stdClass();
     $strongarm->disabled = FALSE; /* Edit this to true to make a default strongarm disabled initially */
     $strongarm->api_version = 1;
     $strongarm->name = 'features_testing';
     $strongarm->value = array(
       'key' => array(
         'stuff' => array(),
         // Added this!
         'otherstuff' => array(
           'visible' => FALSE,
           'weight' => 0,
         ),
       ),
     );
     $export['features_testing'] = $strongarm;
   

6. Clear all caches
7. Run 'drush fr' on your Feature and it'll say "Current state already matches defaults, aborting."
8. But if you do 'drush vget features_testing' you'll see that the variable still has the old value!
9. If you edit the MODULE.strongarm.inc and make any of the values to something that doesn't evaluate to FALSE, for example, changing 'weight' to 1, then Features will see the changes!

When I downgrade Features to 2.5, it correctly marks the Feature as "Needs review" and running 'drush fr' will change the variable to have the value specified in code.

Using 'git bisect', I was able to find the exact revision that introduces this problem:

http://cgit.drupalcode.org/features/commit/?id=19057448a5960f7d0561711b6...

... which is from the first patch committed on #2497139-4: Alter hooks causing overrides due to object properties not sorted

I'm still not entirely sure what it is about those changes that causes this problem, but at least we know where to start. :-)