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
* Remove the given item from the table tree. Remove our listener if the
	 * item's user data is a an entry then set the user data to null
	 * 
	 * @param item
	 *            the item to remove
	 */
	private void removeItem(TableTreeItem item) {
		Object data = item.getData();
		if (data instanceof IPropertySheetEntry)
			((IPropertySheetEntry) data)
					.removePropertySheetEntryListener(entryListener);
		item.setData(null);
		item.dispose();
	}
	/**
	 * Reset the selected properties to their default values.
	 */
	public void resetProperties() {
		
		IStructuredSelection selection = (IStructuredSelection) getSelection();
		
		Iterator enum = selection.iterator();
		while (enum.hasNext())
			((IPropertySheetEntry) enum.next()).resetPropertyValue();
	}
	/**
	 * Sets the error message to be displayed in the status line.
	 * 
	 * @param errorMessage
	 *            the message to be displayed, or <code>null</code>