I'm trying to vote to close this question as a duplicate of this one. The former question had just been asked 20 minutes ago, whereas the latter one was closed as a duplicate back in 2010 and hasn't been edited by a human user since 2011.
However, when I try to vote to close the much newer one as a duplicate of that much older one (which, by the way, is closed as a duplicate of two other questions that, obviously, existed back in 2010), I get an error message saying that my closure would result in a duplicate circle. This wouldn't be the case here.
I did some research using my 10k+ abilities, and found the following:
- I attempted to close this new question (which I'll call A) as a duplicate of B.
- B is closed as a duplicate of two questions, C and D. (C is open, and D is deleted.)
- D is closed as a duplicate of B and C.
Here's a flowchart:
So it seems like there is indeed a circle, between B and D, which are both closed as duplicates of each other. But this circle is broken now that D is deleted; effectively B is now closed as a duplicate of only C, which means that my closure would be A -> B -> C, which is not a circle.
And even if D were to not be deleted, a circle between B and D shouldn't affect my ability to close A as a duplicate of B, because B also has C as a target, which exists and is open.
So effectively, the system seems to be overzealously blocking circles, even though there are ways for it to not be circles. Also, this would have been extremely confusing to a <10k user, as there would have been no way for them to figure out what was going on; I could only have known about the third bullet with my 10k-vision.
Can we please change the duplicate "circle" checker so that it does not give the error message if there is a way for a certain duplicate path to not be a circle, even if there does exist one circular path? In other words, only give the error if the only possible paths are circles? Or at the very least disregard deleted posts when calculating circles (the system now blocks humans from deleting duplicate targets, but there are older cases like this one where it wasn't blocked, and it can still happen as a result of Roomba deletions)?