[IBLJerry]

I have tested a bit the dual talent spec on the PTR (I'm the author of Talented). I have transfered 4 characters over the course of the PTR, two very early (twice my level 80), before the PTR went up in fact, one a little bit later (23 hunter as I needed to work on pet talents) and a final one much later (one 70 mage, for checking something), I think it was while 9742 was on the PTR. Out of the 4, I bought the dual spec only for the two warriors, quite early. I remember it worked fine.

Edit: With one warrior, I did unlearn talents at least four or five times, and reapplied specs with "problematic" talents like Devastate without having an issue. The same spec that had issue on live.

Actually, I do not remember having any issue with the talent on any character, even the warriors. It worked fine. There are a lot of stuff that I did not try (zoning with a hunter pet, for instance), so I can't say for sure that everything was working fine, but what I did work on was solid. Nothing like we saw when the patch was deployed.

My guess is that it's quite different to transfer a character to a new database, and work from here, than it is to convert an (old, big) database to a new format, and that a small difference in the internal DB may have been the root cause of all the issues that has been experienced on live.

It's really hard to determine the full extent of issue that a single failed assertion can have, without access to the source code.

Maybe they should clone a live server db, apply the patch to it beforehand and check there, as part of the QA process that goes on once a patch is ready. Maybe they already do that but it didn't trigger the bug for some reason... The fact is that, even if this bug is really easy to see on live server, that doesn't mean that it was easy to find beforehand. And I can definitly attest that it was working much better on the PTR than on live.