An invalid oldid gives an error:
https://en.wikipedia.org/w/index.php?oldid=12345678901234
But an invalid curid just shows the Main Page:
https://en.wikipedia.org/w/index.php?curid=12345678901234
This behavior doesn't make sense. There should be an error message for invalid curid values too.
Version: 1.23.0
Severity: minor