Apply a fix to product deletion by directly manipulating product reference...

Apply a fix to product deletion by directly manipulating product reference field data instead of depending on the entity_metadata_wrapper().

modules/product_reference/commerce_product_reference.module

@@ -176,7 +176,18 @@ function commerce_product_reference_commerce_product_delete($product) {
 
         // Loop over each entity and remove the reference to the deleted product.
         foreach ($entities as $entity_id => $entity) {
-          $entity = commerce_entity_reference_delete($entity_type, $entity, $field_name, $product->product_id);
+          foreach ($entity->{$field_name} as $langcode => $items) {
+            foreach ($items as $delta => $item) {
+              if ($item['product_id'] == $product->product_id) {
+                unset($entity->{$field_name}[$langcode][$delta]);
+              }
+            }
+
+            // If the reference field is empty, wipe its data altogether.
+            if (count($entity->{$field_name}[$langcode]) == 0) {
+              unset($entity->{$field_name}[$langcode]);
+            }
+          }
 
           // Store the changes to the entity.
           entity_save($entity_type, $entity);