If rc_this_oldid is zero, you should not diff at all

When the RC feed contains entries from the newusers log, the makebot log, or other logged operations that do not have a corresponding revision, the resulting item is broken in (at least) two ways: 1. The URL goes to http://.../w/index.php?title=User:Example&diff=0&oldid=prev (which is a broken link leading to an error page), and 2. the item description ends with “New page” (prefixing the empty “diff”).

Version: unspecified
Severity: trivial

Attached: