Bug 209910 Drag the dataset from library, the resultset column number is doubled
Reproduce step: 1. Create one data set in library. 2. Drag it into a report design. 3. Open the data set editor, switch to the output column page, the result set number is doubled. I found there is something wrong in the org.eclipse.birt.report.model.api.util.CompatibilityUtil class. The method addStructures()will add structures list twice when the propHandle is not local.
data/org.eclipse.birt.report.data.adapter/src/org/eclipse/birt/report/data/adapter/impl/MetaDataPopulator.java
public static IResultMetaData retrieveResultMetaData(
			DataSetHandle dataSetHandle ) throws BirtException
	{
		List resultSetList = null;
		if ( dataSetHandle instanceof OdaDataSetHandle )
		{
			PropertyHandle handle = dataSetHandle.getPropertyHandle( OdaDataSetHandle.RESULT_SET_PROP );
			if ( handle.isLocal( ) )
				resultSetList = handle.getListValue( );
		}
		else if ( dataSetHandle instanceof ScriptDataSetHandle )
		{
			PropertyHandle handle = dataSetHandle.getPropertyHandle( DataSetHandle.RESULT_SET_HINTS_PROP );
			if ( handle.isLocal( ) )
				resultSetList = handle.getListValue( );
		}
		else
		{
			return null;
		}
		List computedList = (List) dataSetHandle.getProperty( OdaDataSetHandle.COMPUTED_COLUMNS_PROP );
		List columnMeta = new ArrayList( );
		ResultSetColumnDefinition columnDef;
		int count = 0;
		
		if ( resultSetList != null && !resultSetList.isEmpty( ) )
		{
			ResultSetColumn resultSetColumn;
			HashSet orgColumnNameSet = new HashSet( );
			HashSet uniqueColumnNameSet = new HashSet( );