Bug 319961 Reset perspective fails with parts moved into the editor area
1. Start a fresh e4 workbench 2. Move the Javadoc view into the editor area 3. Reset the perspective 4. Open the Javadoc view Result: The Javadoc view is opened in the editor area. In the bottom stack there still is a tab for the Javadoc view; this tab can be clicked, but it will activate the view in the editor area. The toolbar, however, is shown in the bottom stack.
bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/ui/internal/workbench/PartServiceImpl.java
MPlaceholder sharedPartRef = AdvancedFactoryImpl.eINSTANCE.createPlaceholder();
		sharedPartRef.setElementId(sharedPart.getElementId());
		sharedPartRef.setRef(sharedPart);
		return sharedPartRef;
	}
	private MPart addPart(MPart providedPart, MPart localPart) {
		if (providedPart == localPart && isInContainer(providedPart)) {
			return providedPart;
		}
		MPartDescriptor descriptor = findDescriptor(providedPart.getElementId());
		if (descriptor == null) {
			if (providedPart != localPart) {
				MPartStack stack = BasicFactoryImpl.eINSTANCE.createPartStack();
				if (providedPart.getCurSharedRef() instanceof MPlaceholder) {
					stack.getChildren().add(providedPart.getCurSharedRef());
				} else {
					stack.getChildren().add(providedPart);
				}
				rootContainer.getChildren().add(stack);
			}
		} else {
			if (providedPart != localPart && !descriptor.isAllowMultiple()) {
				return localPart;
			}
			if (isInContainer(providedPart)) {
				return providedPart;
			}
			String category = descriptor.getCategory();
			if (category == null) {
				addToLastContainer(null, providedPart);