Renaming or copying a page should also rename the title if it was identical to the original document name

After renaming a page i was confused of getting the old name in the path and headline of the page. A second try of renaming the page tolds me, that a page with the given name already exists.

The answer was that the page name is not equal to the page title. To avoid this 'userunfriendly' effect, renaming a page should automatically include renaming the title of the page.