'In Content' add/edit actions don't respect Node Revisions

Any progress on this issue? It seems like if we can create revisions from the node form, we should be able to do it more generally for all entity updates. I am willing to chip in some development time toward this, but am not too familiar with Entity API. Any suggestions on how we would approach this update?

Okay, here's what I've found...

In field_collection.pages.inc, the add/edit form calls this function:

function field_collection_item_form_submit($form, &$form_state) {
  $field_collection_item = field_collection_item_form_submit_build_field_collection($form, $form_state);
  $field_collection_item->save();

Now we compare that to what's being called on node save:

function field_collection_field_presave($host_entity_type, $host_entity, $field, $instance, $langcode, &$items) {
  foreach ($items as &$item) {
    if (isset($item['entity']) || !empty($host_entity->revision)) {
      if ($entity = field_collection_field_get_entity($item)) {
        if (!empty($entity->is_new)) {
          $entity->setHostEntity($host_entity_type, $host_entity, LANGUAGE_NONE, FALSE);
        }
        if (!empty($host_entity->revision)) {
          $entity->revision = TRUE;
          $is_default = entity_revision_is_default($host_entity_type, $host_entity);
          if (!isset($is_default) || $is_default) {
            $entity->default_revision = TRUE;
            $entity->archived = FALSE;
          }
        }
        $entity->save(TRUE);
        ...
      }
    }
  }
}

So I tried to copy some of this to the add/edit form. I added the following:

function field_collection_item_form_submit($form, &$form_state) {
  $field_collection_item = field_collection_item_form_submit_build_field_collection($form, $form_state);
  
  $field_collection_item->revision = TRUE;
  $field_collection_item->default_revision = TRUE;
  $field_collection_item->archived = FALSE;
  
  $field_collection_item->save();
    
  drupal_set_message(t('The changes have been saved.'));
  $form_state['redirect'] = $field_collection_item->path();
}

And this worked! Kinda... It did save the node and create a new revision for the field collection.

Unfortunately, I'm using the Revisioning module, which keeps different states of the node, and that's really throwing things off. If I have a node in a saved/draft state, and edit the node again, I lose the previous modifications. So while this approach kinda works, it's obviously not the "right way" to be doing this.

Any thoughts from those who are deeply entrenched with this module?

I've made a patch that modifies the submit function to check the host entity's options and, if revisions are enabled, signals the field collection item's save() function to create a new host entity revision. This will work for adds and edits.

I personally would like host entity revisions to also be created upon deletion of a field collection item. Unfortunately, this goes through the field_collection_item_delete_confirm_submit() function, not field_collection_item_form_submit(), and seems to be more complicated.

On a side note, the field collection item's save() function has a comment that says "If this is creating a new revision, also do so for the host entity." and the nearby code does a check for $this->is_new_revision. I think either that comment is wrong or else the code is supposed to check $this->is_new. If the latter, a new host entity would already be always created when a field collection item is added (except with explicitly skipped with $skip_host_save), regardless of the changes in my patch.