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
/*
	 * Implements method from IWorkingSetPage
	 */
	public void finish() {
		String workingSetName= fWorkingSetName.getText();
		ArrayList elements= new ArrayList(10);
		findCheckedElements(elements, fTree.getInput());
		if (fWorkingSet == null) {
			IWorkingSetManager workingSetManager= PlatformUI.getWorkbench().getWorkingSetManager();
			fWorkingSet= workingSetManager.createWorkingSet(workingSetName, (IAdaptable[])elements.toArray(new IAdaptable[elements.size()]));
		} else {
			
			IAdaptable[] oldItems= fWorkingSet.getElements();
			for (int i= 0; i < oldItems.length; i++) {
				IResource oldResource= null;
				if (oldItems[i] instanceof IResource) {
					oldResource= (IResource)oldItems[i];
				} else {
					oldResource= (IResource)oldItems[i].getAdapter(IResource.class);
				}
				if (oldResource != null && oldResource.isAccessible() == false) {
					elements.add(oldResource);
				}
			}
			fWorkingSet.setName(workingSetName);
			fWorkingSet.setElements((IAdaptable[]) elements.toArray(new IAdaptable[elements.size()]));
		}
	}
	private void validateInput() {
		String errorMessage= null;