Wikimedia Bugzilla is closed!

Wikimedia migrated from Bugzilla to Phabricator. Bug reports are handled in Wikimedia Phabricator.
This static website is read-only and for historical purposes. It is not possible to log in and except for displaying bug reports and their history, links might be broken. See T12963, the corresponding Phabricator task for complete and up-to-date bug report information.

If user is saving the page as redirect to another page which already is redirect, he should get some kind of confirmation dialog like:

Warning: Double redirect creation.

The target [[Foo]] is already redirect to [[Bar]].

[Fix the target]   [Save anyway]

Note that a more frequent source of redirects is going to be changing an existing page (by move or manual redirect) to which other pages already redirect.