Copying a page which has page key would create a new page with page key as (page key)1
Steps to reproduce:
Create a page A and add page key 100
Create a page B and add page key 1001
Copy the page A and save the page
The page key should not be copied at all.
Rationale: The page key is something unique to a Scroll Page that is defined by the Author / Doc-Admin. Thus copying will not create sensible values for the user, just like the Confluence page title "Copy of ..." is never left as is by a user.
A page would be created with duplicate page key as '1001' without any error message