Bug 329482 Uninstantiated part may be rendered when closing another part in the same stack
1. Activate the 'Javadoc' view. 2. Activate the 'Package Explorer' view. 3. Shutdown. 4. Restart. 5. Ctrl+3 > Properties 6. Hide the 'Properties' view. 7. Now the 'Problems' view is the selected element. It should be the 'Javadoc' view.
bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/ui/internal/workbench/PartActivationHistory.java
}
	private MPart getSiblingActivationCandidate(MPart part) {
		MPlaceholder placeholder = part.getCurSharedRef();
		MUIElement candidate = getSiblingSelectionCandidate(part, placeholder == null ? part
				: placeholder);
		return (MPart) (candidate instanceof MPlaceholder ? ((MPlaceholder) candidate).getRef()
				: candidate);
	}
	private MUIElement getSiblingSelectionCandidate(MPart part, MUIElement element) {
		List<MUIElement> siblings = element.getParent().getChildren();
		for (MPart previouslyActivatedPart : generalActivationHistory) {
			if (previouslyActivatedPart != part && previouslyActivatedPart.isToBeRendered()) {
				if (siblings.contains(previouslyActivatedPart)) {
					return previouslyActivatedPart;
				}
				MPlaceholder placeholder = partService.getLocalPlaceholder(previouslyActivatedPart);
				if (placeholder != null && placeholder.isToBeRendered()
						&& siblings.contains(placeholder)) {
					return placeholder;
				}
			}
		}
		return null;
	}
	MUIElement getSiblingSelectionCandidate(MPart part) {
		MPlaceholder placeholder = part.getCurSharedRef();
		return getSiblingSelectionCandidate(part, placeholder == null ? part : placeholder);
	}
}