Bug 334559 EPartService's part searching path may not include parts outside of the active perspective
tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/application/EPartServiceTest.java
.createPlaceholder();
		placeholderA.setRef(partA);
		partA.setCurSharedRef(placeholderA);
		stackA.getChildren().add(placeholderA);
		stackA.setSelectedElement(placeholderA);
		MPartStack stackB = BasicFactoryImpl.eINSTANCE.createPartStack();
		perspective.getChildren().add(stackB);
		MPlaceholder placeholderB = AdvancedFactoryImpl.eINSTANCE
				.createPlaceholder();
		placeholderB.setRef(partB);
		partB.setCurSharedRef(placeholderB);
		stackB.getChildren().add(placeholderB);
		stackB.setSelectedElement(placeholderB);
		MPartStack stackC = BasicFactoryImpl.eINSTANCE.createPartStack();
		perspective.getChildren().add(stackC);
		MPlaceholder placeholderC = AdvancedFactoryImpl.eINSTANCE
				.createPlaceholder();
		placeholderC.setRef(partC);
		partC.setCurSharedRef(placeholderC);
		stackC.getChildren().add(placeholderC);
		stackC.setSelectedElement(placeholderC);
		initialize(applicationContext, application);
		getEngine().createGui(window);
		EPartService partService = window.getContext().get(EPartService.class);
		partService.activate(partA);
		partService.activate(partB);
		partService.activate(partA);
		partService.hidePart(partA);
		MPart activePart = partService.getActivePart();
		if (activePart == partB) {