Bug 163018 An error extension will lead the report contain chart can't be opened and can not new a report.
Details: An error extension will lead the report contain chart can't open In org.eclipse.birt.report.tests.model has an error extension. When run the birt use workbenck, the report contain chart can't be opened and it can not new a report.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/metadata/ElementDefn.java
if ( hasStyle( ) )
		{
			ElementDefn styleDefn = (ElementDefn) dd
					.getElement( ReportDesignConstants.STYLE_ELEMENT );
			
			
			if ( styleDefn == null )
			{
				throw new MetaDataException( new String[]{this.name},
						MetaDataException.DESIGN_EXCEPTION_STYLE_NOT_DEFINED );
			}
			if ( styleDefn.properties.containsKey( property.getName( ) ) )
			{
				throw new MetaDataException( new String[]{property.getName( ),
						this.name},
						MetaDataException.DESIGN_EXCEPTION_DUPLICATE_PROPERTY );
			}
		}
		super.addProperty( property );
	}
	/**
	 * Returns the semantic validation trigger definition collection.
	 * 
	 * @return the semantic validation trigger definition collection
	 */
	public SemanticTriggerDefnSet getTriggerDefnSet( )
	{
		if ( triggerDefnSet == null )
			triggerDefnSet = new SemanticTriggerDefnSet( );
		return triggerDefnSet;