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/BundleHelper.java
Iterator bundleIter = gatherMessageBundles( locale ).iterator( );
		while ( bundleIter.hasNext( ) )
		{
			String translation = (String) ( (PropertyResourceBundle) bundleIter
					.next( ) ).handleGetObject( resourceKey );
			if ( translation != null )
				return translation;
		}
		return ""; 
	}
	/**
	 * Return a message resource bundle list for the given locale. A message key
	 * should be look into the files in the sequence order from the first to the
	 * last. Content of the list is
	 * <code>java.util.PropertyResourceBundle</code>
	 * <p>
	 * If the given locale is <code>null</code>, locale of the current thread
	 * will be used.
	 * 
	 * @param locale
	 *            locale to use when locating the bundles.
	 * 
	 * @return a message file list for the given locale.
	 */
	private List gatherMessageBundles( ULocale locale )
	{
		if ( locale == null )
			locale = ThreadResources.getLocale( );
		List bundleHierarchy = new ArrayList( );
		if ( this.baseName == null )