Bug 81878 cannot edit working sets from package explorer [package explorer]
3.1 M4 1. open pkg explorer and select a working set. 2. run "edit active working set" from the pkg explorer view menu. 3. select another project to include in the active working set. 4. selection finish. The dialog doesn't close and the pkg explorer doesn't update. If you cancel the dialog, turn off the working set filter and re-enable the edited working set is applied. It's although the working set was modified in the dialog, but a listener crashed (probably the pkg explorer).
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/workingsets/ViewActionGroup.java
public static final int SHOW_PROJECTS= 1;
	public static final int SHOW_WORKING_SETS= 2;
	public static final String MODE_CHANGED= ViewActionGroup.class.getName() + ".mode_changed"; 
	
	private static final Integer INT_SHOW_PROJECTS= new Integer(SHOW_PROJECTS);
	private static final Integer INT_SHOW_WORKING_SETS= new Integer(SHOW_WORKING_SETS);
	
	private final IPropertyChangeListener fChangeListener;
	
	private int fMode;