Bug 145520 Group name will not show up in group list if the group use default name and key expression has no value
Description: Group name will not show up in group list if key expression has no value. Steps to reproduce: 1. Insert a table into report, bind it to a data set 2. Switch to property editor -> groups 3. Click on add button to open new group dialog, then press ok button Expected result: A new group with default name will be added to group list Actual result: A new group is added to group list, but without group name. But when let group tab lost focus and get focus again, you can see the group name.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/Module.java
*            be used instead.
	 * @return the corresponding locale-dependent messages. Return
	 *         <code>""</code> if translation can not be found, or
	 *         <code>resourceKey</code> is blank or <code>null</code>.
	 */
	public String getMessage( String resourceKey, ULocale locale )
	{
		if ( StringUtil.isBlank( resourceKey ) )
			return null;
		if ( locale == null )
			locale = ThreadResources.getLocale( );
		
		String msg = translations.getMessage( resourceKey, locale );
		if ( msg != null )
			return msg;
		
		String baseName = getStringProperty( this, INCLUDE_RESOURCE_PROP );
		if ( baseName == null )
			return null;
		
		msg = BundleHelper.getHelper( this, baseName ).getMessage( resourceKey,
				locale );
		return msg;
	}
	/**
	 * Return the folder in which the design file is located. The search depend
	 * on the {@link #getFileName()}.
	 * 
	 * @return the folder in which the design file is located. Return
	 *         <code>null</code> if the folder can not be found.