Bug 160184 [API]DataSetID.toString() should return null but return "null"
Description: DataSetID.toString() should return null but return "null" Steps to reproduce: Run below codes: new DataSetID( null, 0, null ).toString(); Expected result: null. Actual result: "null"
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/api/DataSetID.java
public long getRowID( )
	{
		return rowId;
	}
	public DataSetID( String dataSetName )
	{
		this.dataSetName = dataSetName;
	}
	void append( StringBuffer buffer )
	{
		if ( parent != null )
		{
			buffer.append( "{" );
			parent.append( buffer );
			buffer.append( "}." );
			buffer.append( rowId );
			buffer.append( "." );
			buffer.append( queryName );
		}
		else
		{
			buffer.append( dataSetName );
		}
	}
	public String toString( )
	{
		if ( dataSetName != null )
		{
			return dataSetName;
		}