Just a pair of bugs I notice. Posting them here to see if any blizz employee actually reads the warlock forums. Both involve hard casting DB anyways, so will rarely matter. Both are actually about doom, too.
First one is strictly bad, if you hard cast DB and a core procs during the cast, it will consume the core and apply doom as if it was an instant cast, but with the full cast time.
Second one could theoretically be of use, but probably not. If you proc some cores, but the expire before you use them up, you next DB will apply doom, even if hard casted. So if you lose your cores between packs, you can still start the next fight with a doom if you hard cast. Might require a modicum of coordination with the tank.
My theory why these bugs happen is that I assume there is a flag, applyDoom or something, that is set to true whenever you proc Demonic Core, but is only removed when doom is applied and you don’t currently have cores.
Sort of a:
When DB hits,
If (applyDoom == True)
Target receives Doom
If (Demonic Core < 1)
applyDoom = False
I recall there was a similar bug where doom would only apply if you had Demonic cores when DB hit, regardless of if it consumed a core or not, so I am guessing the problem revolves around the fact that doom triggers are tested on spell hit and not spell cast.
Of course, I am working off of an intro programming course worth of knowledge from five years ago, so what do I know? Could all be wrong.