Bug 327980 Part activation history should not be perspective-dependent
bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/ui/internal/workbench/PartActivationHistory.java
parent = (MUIElement) ((EObject) placeholder).eContainer();
		}
		return parent instanceof MApplication ? null : parent instanceof MArea ? (MArea) parent
				: isInArea(parent);
	}
	/**
	 * Finds and returns a part that is a valid candidate to be granted activation.
	 */
	private MPart getActivationCandidate(MPart part) {
		
		Collection<MPart> candidates = part.getContext().get(EPartService.class).getParts();
		for (MPart candidate : candidates) {
			
			if (part != candidate && candidate.isToBeRendered() && candidate.isVisible()) {
				MPlaceholder placeholder = candidate.getCurSharedRef();
				if (placeholder != null) {
					
					if (!placeholder.isToBeRendered() || !placeholder.isVisible()) {
						continue;
					}
				}
				MElementContainer<MUIElement> parent = placeholder == null ? candidate.getParent()
						: placeholder.getParent();
				
				if (isValid(parent)) {
					
					
					if (parent instanceof MGenericStack<?>) {
						
						MUIElement element = parent.getSelectedElement();