Bug 30751 [Viewers] Closing all projects doesnt clear package browser list [browsing]
In the java browsing perspective, if you close all projects, the packages browser still has a list of all the packages from the last opened project.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/StructuredViewer.java
* <p>
 * If <code>setSelection</code> is called from
 * within <code>preserveSelection</code>, the call to <code>updateSelection</code>
 * is delayed until the end of <code>preserveSelection</code>.
 * </p>
 * <p>
 * Subclasses do not typically override this method, but implement <code>setSelectionToWidget</code> instead.
 * </p>
 */
public void setSelection(ISelection selection, boolean reveal) {
	Control control = getControl();
	if (control == null || control.isDisposed()) {
		return;
	}
	if (!inChange) {
		setSelectionToWidget(selection, reveal);
		ISelection sel = getSelection();
		updateSelection(sel);
		firePostSelectionChanged(new SelectionChangedEvent(this, sel));
	} else {
		restoreSelection = false;
		setSelectionToWidget(selection, reveal);
	}
}
/**
 * Parlays the given list of selected elements into selections
 * on this viewer's control.
 * <p>
 * Subclasses should override to set their selection based on the
 * given list of elements.