complete the integration with Commerce Product Option

Unfortunately, the integration of the two modules isn't complete yet (as statet somewhere at the project page) ;). It simply has not yet finished.

z_khn06, I really would like to help you. But to be honest, I do not know that, but I really doubt, that there is a simple way yet. Someone have to code it :(. Sorry

Anyone?

I'd like to work on this as it'd be helpful for a website I'm building. Does anyone know where to start to do this?

Same issue. We need this functionality to work also. Currently no suggestions, subscribing.

Still nothing a year later? I'm going to have to give this a go myself. If anyone has attempted, please let me know how far you got. (sandbox code or whatever would be greatly appreciated)

Hey I had this same problem over the past few days and figured I'd do my best to get to the bottom of it until a full integration with this bug fixed is finished. I was receiving this error when I would edit one of my product display nodes that contains a product reference field that references products with commerce_options attached (my site's t-shirts use sizes as options). What I found was that when I would go to edit the product display node itself, individually editing each product and then re-saving them using their respective inline entity forms would cause no problems. But if I only edited one of them or none at all, after saving the product display node I would receive the malformed bundle key error for an entity of type commerce_option. Upon checking my database, I realized that not individually editing and saving each product's inline entity form would place a NULL value under their respective product option fields, and would save them with the new node. That is what was throwing the error, as products that use commerce_options with add-to-cart forms require this set_id or throw you the error.

My workaround (which may not be the best, but is a short fix until we have an actual fix), was to implement a hook_entity_presave($entity, $type). When my product display nodes are saved, it loops through each product_id referenced by the product reference field, loads that product id, and checks it's commerce_option reference field to see if it has had a NULL set_id placed in it, rather than the appropriate one for that product type. If it is indeed NULL, I simply added the correct one and performed a commerce_product_save($product) on it. Since my commerce_option set_ids are named "{product_type}_options", it was easy to make this dynamic for all of my product types based on which type I was editing. I'll paste my code below, I hope this helps until we have a real fix!.

(This can probably be fixed in the same way via a hook_validate or hook_submit but I chose to go with hook_entity_presave().

function gng_entity_presave($entity, $type) {

        // If it is a Product Display Node
	if (isset($entity->field_product_reference)) {
		foreach ($entity->field_product_reference['und'] as $product_reference) {
			$product_id = $product_reference['product_id'];
			$product = commerce_product_load($product_id);

                        //If the set_id is empty, add the appropriate type and save
			if (isset($product->field_product_options) && empty($product->field_product_options['und'][0]['set_id'])) {
				$product->field_product_options['und'][0]['set_id'] = $product->type . '_options';
				commerce_product_save($product);
			}
		}
	}
}

Closing. No development for D7 anymore.