Here's a solution that works. #1623

FYI: Link to Mark Dexter's test of this code in this patch documenting that it creates the "duplicate content" issue when multiple contacts are assigned to the author's userid.

https://groups.google.com/d/msg/joomla-dev-general/sVFw9reqGGw/PFdDjztChaMJ

It would be unfortunate if this patch went in and created yet another recurrence of the same problem.

On the tracker, @elinw you mentioned a successful test of your patch. Did you test for the duplicate content issue on these other databases?

I'd really appreciate it @elinw, if you would please test this patch. It provides for your feature and it does so in a flexible manner recommended by Thomas so that it is possible for developers to easily swap out the core Author Profile for their own.

More importantly, it actually addresses the real problem which is the join between the contact and articles table. So, the problems Mark is describing, the same problem created by this patch, can once and for all, be fixed. And, the feature is preserved, in fact, it's better.

I'm sorry to be so insistent on this but I wish I had been much more insistent three years ago when I said these things would happen. There has been too much harm done. I'm not going to make the same mistake again - I'm making a stand on this.

We've provided a hot fix for sqlsrv users instead of doing the conditional.