Bug 153378 [Regression]Label text won't show up when the text key is not found
Steps to reproduce: 1.Add a label, set text to "aaa" 2.Add a resource file "a" to the report, add a text key "k1" which is not in the a.properties to the label 3.Preview in Web Viewer Expected result: Label display "aaa" when the text key is not found Actual result: Nothing in preview
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/util/DocumentUtil.java
}
		else if ( source instanceof TextItem )
		{
			String resourcekey = source.getStringProperty( sourceDesign,
					TextItem.CONTENT_RESOURCE_KEY_PROP );
			if ( resourcekey == null )
				return;
			String displayValue = sourceDesign.getMessage( resourcekey );
			target.setProperty( TextItem.CONTENT_PROP, displayValue );
			target.setProperty( TextItem.CONTENT_RESOURCE_KEY_PROP, null );
		}
	}
	/**
	 * if the image item reference a library image, which uses a library
	 * embedded image, copy the embedded image into the target design.
	 * 
	 * @param targetDesign
	 *            the target design to add the copied embedded image
	 * @param sourceDesign
	 *            the source design from which to get the copy
	 * @param target
	 *            the target element to resolve the embedded image
	 * @param source
	 *            the source element
	 */
	static void resolveImageItem( ReportDesign targetDesign,
			ReportDesign sourceDesign, DesignElement target,
			DesignElement source )
	{
		assert targetDesign != null && target != null && source != null;