Friendly URLs of products in version 1.6 and 1.7

[Peter]

Hello PrestaShop,

We are planning to upgrade PrestaShop from 1.6 to 1.7.  I noticed that the product routing, in the SEO & URLs Shop Parameters configuration, has changed between these versions and hence this could create differences in product URL's between the 1.6 store and the 1.7 store.

For example, version 1.6 default product routing is:  {category:/}{id}-{rewrite}{-:ean13}.html

while in version 1.7 it is: {category:/}{id}{-:id_product_attribute}-{rewrite}{-:ean13}.html

In 1.7, if I have product with combinations will my default product have an id_product_attribute included in the URL?

Or, will this only be included for non default combinations?

For example, if I am selling jeans and I have sizes from 28 to 38, where size 28 is my default product, will default URL be: jeans/101-riveted-denim.html or will it be jeans/101-id_product_attribute-riveted-denim.html?  (where 101 is my product id)

If my product is a simple product and not a product with combination, will the URL include the id_product_attribute?

++Tx

Peter