Bug 328946 Part activation history may return incorrect candidate if no placeholders could be found in a perspective
1. Window > Open Perspective > Other... > CVS Repository Exploring 2. Hide the 'CVS Repositories' view. 3. The 'History' view should become active, it is not.
bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/ui/internal/workbench/PartServiceImpl.java
}
			} else if (object instanceof MPerspective) {
				MPerspective persp = (MPerspective) object;
				for (MWindow dw : persp.getWindows()) {
					if (isInContainer(dw, element))
						return true;
				}
			} else if (object instanceof MWindow) {
				MWindow win = (MWindow) object;
				for (MWindow dw : win.getWindows()) {
					if (isInContainer(dw, element))
						return true;
				}
			}
		}
		if (container instanceof MWindow) {
			MWindow win = (MWindow) container;
			for (MWindow dw : win.getWindows()) {
				if (isInContainer(dw, element))
					return true;
			}
		}
		if (container instanceof MPerspective) {
			MPerspective persp = (MPerspective) container;
			for (MWindow dw : persp.getWindows()) {
				if (isInContainer(dw, element))
					return true;
			}
		}
		return false;