Bug 329930 Resetting a perspective while its active part is not defined in the perspective causes the perspective to not have an active part after the reset
1. Window > Show View > Console 2. Window > Reset Perspective... > OK 3. No parts are active.
bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/ui/internal/workbench/PartServiceImpl.java
if (!isInContainer(providedPart)) {
				adjustPlaceholder(providedPart);
				addToLastContainer(null, providedPart);
			}
		} else {
			if (providedPart != localPart && !descriptor.isAllowMultiple()) {
				
				return localPart;
			}
			
			if (isInContainer(providedPart)) {
				return providedPart;
			}
			
			adjustPlaceholder(providedPart);
			String category = descriptor.getCategory();
			if (category == null) {
				
				addToLastContainer(null, providedPart);
			} else {
				List<MElementContainer> containers = modelService.findElements(getContainer(),
						null, MElementContainer.class, Collections.singletonList(category));
				if (containers.isEmpty()) {
					
					addToLastContainer(category, providedPart);
				} else {
					
					MElementContainer container = containers.get(0);
					MPlaceholder placeholder = providedPart.getCurSharedRef();
					if (placeholder == null) {