Join condition missing for Field API table(s)

Hi,

I have a kind of complex case, but I think I've found an instance where a necessary JOIN condition isn't being added to the query generated by Views. I've dug around for a few hours in the code, and while I couldn't find the place the necessary code is missing, I know what's wrong and have figured out how to fix it with a hook_views_query_alter(). Here's what I have:

I'm using the File Entity module (Drupal 7) to have fieldable files. My site includes a taxonomy vocabulary for primate taxa (family, subfamily, genus, species, etc.), where each primate taxon is a Drupal taxonomy term. I also have images of the primate taxa, but since each image needs to have its own fields (caption, photo contributor, other information), images are standalone File entities, each of which has a Taxonomy Term Reference field containing the primate taxon the image represents.

Here's what I needed to do: build a View that takes a file ID for an image as an argument, then retrieve the taxonomy term (primate species) for that image. Next, find all other images of that same primate species and display them as well.

My View uses File as its base field and takes File: File ID as an argument. I then added a Relationship for the field containing the taxonomy term (Field: Primate Taxa). I then added the relationship "Taxonomy Term: File Using Primate Taxa" and set it to use the taxonomy term relationship I mentioned in the last sentence. I then set to display the images from the file relationship. What I got, though, included a bunch of wrong images.

I'm using the "Primate Taxa" field for more than just image-taxonomy relationships; several types of nodes on my site use the field as well. What's happening is that the View isn't ensuring that items from the Field API table for the taxonomy term reference field have entity_type == 'file.' Instead, I'm getting random files that happen to have FIDs that are the same as NIDs stored in the same Field API table.

Here's how I fixed the problem via a hook_views_query_alter():

function MODULE_views_query_alter(&$view, &$query) {
      foreach($query->table_queue as $name => &$data){
		if (!empty($data['join']) && !empty($data['join']->table) && !empty($data['join']->field)
			&& !empty($data['join']->left_field)){
			
			if ($data['join']->table == 'file_managed' && $data['join']->field == 'fid' &&
				$data['join']->left_field == 'entity_id'){
				
				$table_alias = $data['join']->left_table;
				
				// Rough check: try to make sure the table is a Field API table.
				if (strpos($table_alias, 'field_data_') === FALSE){
					continue;
				}

				$join = &$query->table_queue[$table_alias]['join'];
				if (!isset($join->extra)){
					$join->extra = array();
				}
				$join->extra[] = array(
					'field' => 'entity_type',
					'value' => 'file',
				);
	
			}
		}
	}
}

Alternatively, instead of adding the "extra" to the Join object, it also works to just do

$query->add_where(0, "$table_alias.entity_type", 'file'); 

Please let me know if there's any more information I can provide - it looks like whatever is setting up the views_join objects for connecting Field API tables to the file_managed table is forgetting to add the condition to check for the entity_id.

Thanks for your help,
Nathan