Posting in the Magento forums has been disabled pending the implementation of a new and improved forum solution which should better serve the community.
For new questions please post at magento.stackexchange.com, the community-run support site for the Magento community. We will be providing updates on the new forum solution soon. For questions or concerns please email firstname.lastname@example.org.
It’s part of the database query. It means that they are doing a left join to find products with the required_options field not equal 1. (The second part about null equal true has to do with the join for those records that don’t match anything.)
Since you haven’t said where this code is, I can’t describe more fully why it is doing it this way.
I know you can’t put a configurable into a configurable, but you might want to read some documentation to see if you can put a bundle into a grouped. It almost looks like this code is enforcing the opposite of what you want to do.
in <allow_product_types> i added <bundle/>
Now i don’t know how to put this in local instead of modifying the core.
After doing this the method to show the associated products of a grouped is getAssociatedProducts();
This method calls addFilterByRequiredOptions() so if my bundle has the option “isrequired” set to “yes” it isn’t shown.