Bug 321757 EPS adds a part without considering its placeholder if target container is not a part stack
bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/ui/internal/workbench/PartServiceImpl.java
if (isInContainer(dw, part))
						return true;
				}
			}
		}
		if (container instanceof MWindow) {
			MWindow win = (MWindow) container;
			for (MWindow dw : win.getWindows()) {
				if (isInContainer(dw, part))
					return true;
			}
		}
		if (container instanceof MPerspective) {
			MPerspective persp = (MPerspective) container;
			for (MWindow dw : persp.getWindows()) {
				if (isInContainer(dw, part))
					return true;
			}
		}
		return false;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.e4.ui.workbench.modeling.EPartService#activate(org.eclipse.e4.ui.model.application
	 * .MPart)
	 */
	public void activate(MPart part) {
		activate(part, true);