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
return true;
		}
		MElementContainer<MUIElement> parent = element.getParent();
		if (parent == null) {
			MPlaceholder placeholder = element.getCurSharedRef();
			if (placeholder == null) {
				return false;
			}
			parent = placeholder.getParent();
			if (parent == null || !placeholder.isToBeRendered() || !placeholder.isVisible()) {
				return false;
			}
		}
		return element.isToBeRendered() && element.isVisible() && isValid(parent);
	}
	/**
	 * Checks to see if this element and its parents are actually being rendered.
	 */
	boolean isValid(MPerspective perspective, MUIElement element) {
		if (element instanceof MApplication) {
			return true;
		} else if (!element.isToBeRendered() || !element.isVisible()) {
			return false;
		}
		MElementContainer<MUIElement> parent = element.getParent();
		if (parent == null) {
			for (MPlaceholder placeholder : modelService.findElements(perspective, null,
					MPlaceholder.class, null)) {
				if (placeholder.getRef() == element) {
					parent = placeholder.getParent();