Bug 140542 label can't be displayed without resource file or unmatched key
Steps to reproduce: 1.New a report, add a lable with text "aaa" 2.Add a resource file for the report, set key to "key1", value to "actuate", apply the value to the label 3.Clear the resource file in Property Editor->General->Resource File (or change the key to "abc") 4.Preview the report Expected result: 1.Display label text "aaa" on preview or 2.Give a warning message to say resource file is not found or unmatched key Actual result: Nothing displays on preview
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/Module.java
* @param element
	 *            The new element to add.
	 */
	public void addElementID( DesignElement element )
	{
		assert idMap != null;
		assert element.getID( ) > 0;
		Long idObj = new Long( element.getID( ) );
		assert !idMap.containsKey( idObj );
		idMap.put( idObj, element );
		
		long id = element.getID( );
		if ( this.elementIDCounter <= id )
		{
			this.elementIDCounter = id + 1;
		}
	}
	/**
	 * Drops an element from the id-to-element map. Does nothing if IDs are not
	 * enabled. Should be called only from the
	 * {@link org.eclipse.birt.report.model.command.ContentCommand ContentCommand}.
	 * 
	 * @param element
	 *            The old element to remove.
	 */
	public void dropElementID( DesignElement element )
	{
		if ( idMap == null )
			return;
		assert element.getID( ) > 0;