Bug 39027 [working sets] Edit active working set prevents removal of closed projects.
When editing the "active working set" closed projects cannot be removed from the working set, the project has to be opened so it can be removed. This is a minor usability issue.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/workingsets/JavaWorkingSetPage.java
setSubtreeChecked(element, state, true);
		}
	}
	private void updateParentState(Object child, boolean baseChildState) {
		if (child == null)
			return;
		if (child instanceof IAdaptable) {
			IResource resource= (IResource)((IAdaptable)child).getAdapter(IResource.class);
			if (resource != null && !resource.isAccessible())
				return;
		}
		Object parent= fTreeContentProvider.getParent(child);
		if (parent == null)
			return;
		boolean allSameState= true;
		Object[] children= null;
		children= fTreeContentProvider.getChildren(parent);
		for (int i= children.length -1; i >= 0; i--) {
			if (fTree.getChecked(children[i]) != baseChildState || fTree.getGrayed(children[i])) {
				allSameState= false;
				break;
			}
		}
	
		fTree.setGrayed(parent, !allSameState);
		fTree.setChecked(parent, !allSameState || baseChildState);
		
		updateParentState(parent, baseChildState);
	}
	private void initializeCheckedState() {