Bug 310363

As soon as I enable ExtendedWindowBorders in oxygen (or use a decoration that implements it, e.g. BeSpin), I get issues with drag and drop for some (but not all) applications: basically dragging is still possible but all drop targets (that are normally enabled), gets forbidden, and nothing happens on drop. 
Applications for which drag-and-drop gets broken: 
- amarok (dragging music from collection to playlist for instance)
- ark (dragging files from archive to dolphin, or konsole)
- the super simple application that I will attach in next comment (dragging from it to e.g. dolphin)

Applications that are not affected: 
- dolphin.
(I believe it is because it uses a QGraphicsView instead of QTreeView, as the other application do). 

Note: I already discussed the issue with Thomas, who apparently could not reproduce the issue, so first thing I want to check is whether or not someone else can reproduce. (this is somewhat critical, since ExtendedWindowBorders will be one of the very few new features for oxygen in KDE-4.10)


Reproducible: Always

Steps to Reproduce:
1. compile the application provided in the next comment
2. see how drag and drop "works" from the main (and only) window, to e.g. dolphin, to copy/paste files (this is non destructive: dolphin allows you to cancel, after dropping), as long as you use, for instance, Plastique for a window decoration
3. try achieve the same when using latest oxygen (or latest bespin). Here at least, the same drag and drop action fails. Dropping remains disabled in dolphin, and nothing happens on drop.