Bug 141959 Changing data set didn't clean old column bindings
Steps to reproduce: 1.Add two data sets, "ds1" and "ds2" 2.Add a table, binding with "ds1". All "ds1" column bindings generate automatically, that's good 3.Change "ds1" to None Expected result: All "ds1" column bindings should be cleaned Actual result: All "ds1" column bindings are still there. If changing to "ds2", "ds2" column bindings will be added after them.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ColumnBindingDialog.java
combo.setItems( newList );
			String dataSetName = getDataSetName( );
			combo.deselectAll( );
			combo.setText( dataSetName );
			combo.setLayoutData( new GridData( GridData.FILL_HORIZONTAL ) );
			gd = new GridData( );
			gd.widthHint = 250;
			combo.setLayoutData( gd );
			combo.addSelectionListener( new SelectionAdapter( ) {
				public void widgetSelected( SelectionEvent event )
				{
					String value = combo.getText( );
					if ( value.equals( NONE ) )
					{
						value = null;
					}
					if ( canChangeDataSet( value ) )
					{
						try
						{
							startTrans( "" ); 
							DataSetHandle dataSet = null;
							if ( value != null )
							{
								dataSet = SessionHandleAdapter.getInstance( )
										.getReportDesignHandle( )
										.findDataSet( value );
							}
							inputElement.setDataSet( dataSet );
							generateBindingColumns( );