Bug 320338 SplitDropAgent should not use client area for preview rectangle
bundles/org.eclipse.e4.ui.workbench.addons.swt/src/org/eclipse/e4/ui/workbench/addons/dndaddon/SplitDropAgent.java
relTo = relTo.getCurSharedRef();
		MUIElement relParent = relTo.getParent();
		
		if (relParent instanceof MPartSashContainer && !part.getTags().contains("Editor")) {
			relTo = getEditorArea(relParent);
		}
		if (relParent instanceof MPartStack) {
			if (!(stackElement.getTags().contains("Editor")) && relParent.getTags().contains("EditorStack")) { 
				relTo = getEditorArea(relParent);
			} else {
				relTo = relParent;
			}
		}
		
		stackElement.getParent().getChildren().remove(stackElement);
		
		MUIElement toInsert = stackElement;
		if (dragElement instanceof MStackElement) {
			MPartStack newPS = BasicFactoryImpl.eINSTANCE.createPartStack();
			if (relTo.getTags().contains("EditorStack")) { 
				newPS.getTags().add("EditorStack"); 
				newPS.getTags().add("org.eclipse.e4.primaryDataStack"); 
			}
			newPS.getChildren().add((MStackElement) stackElement);
			newPS.setSelectedElement((MStackElement) stackElement);
			toInsert = newPS;
		}
		modelService.insert((MPartSashContainerElement) toInsert,
				(MPartSashContainerElement) relTo, where, 50);
		return true;