I received no testing feedback from my last blog entry about multihead improvements for Plasma Desktop, which underscores the challenges we face with multihead support very nicely.
In any case, today I went through plasma-desktop and moved all the relevant code over to the new solution and committed all the changes to trunk. In theory this should improve plasma-desktop on multihead even further, with things like moving panels around with the mouse working as expected and what not.
Again: in theory, and I can't stress that enough. For those of us without multihead, the changes make zero difference as in the non-multihead case they are just small detours in the code that lead to the exact same calls that were being made previously, so there is quite literally no way of testing this beyond "Hey, it compiles, let's commit that." To know what the impacts are, we need people testing this.
These changes will not be a part of the 4.6beta1 release, but they should be part of beta2. Please install and test that if you have multihead and let me know how it goes.