Bug 56818 [PropertiesView] Clicking on Advanced Properties toggle when categories are collapsed removes the + next to the category
Clicking on Advanced Properties toggle when categories are collapsed removes the plus sign (+) next to the category and it can no longer be expanded. To reproduce: 1.)Open the Properties view. 2.)Have Show Categories turned on, and Show Advanced Properties turned off. 3.)Collapse all open categories. 4.)Click the Show Advanced Properties button. 5.)Note the plus sign goes away and the categories can no longer be expanded. You need to click the Show Advanced Properties button off to see the plus sign again.
bundles/org.eclipse.ui.views/src/org/eclipse/ui/views/properties/PropertySheetViewer.java
public Object getInput() {
		return input;
	}
	/**
	 * Returns the root entry for this property sheet viewer. The root entry is
	 * not visible in the viewer.
	 * 
	 * @return the root entry or <code>null</code>.
	 */
	public IPropertySheetEntry getRootEntry() {
		return rootEntry;
	}
	/**
	 * The <code>PropertySheetViewer</code> implementation of this
	 * <code>ISelectionProvider</code> method returns the result as a
	 * <code>StructuredSelection</code>.
	 * <p>
	 * Note that this method only includes <code>IPropertySheetEntry</code> in
	 * the selection (no categories).
	 * </p>
	 */
	public ISelection getSelection() {
		if (tableTree.getSelectionCount() == 0)
			return StructuredSelection.EMPTY;
		TableTreeItem[] sel = tableTree.getSelection();
		List entries = new ArrayList(sel.length);
		for (int i = 0; i < sel.length; i++) {
			TableTreeItem ti = sel[i];
			Object data = ti.getData();
			if (data instanceof IPropertySheetEntry)