Bug 186742 [Smoke]Can not create a joint dataset[07]
Description: [Smoke]Can not create a joint dataset[07] Build number: 2.2.0.v20070514-0630 Steps to reproduce: 1, New two datasets ds1 and ds2 2, New a joint dataset 3, Select ds1 as the left dataset Expected result: The dataset can be selected successfully and show all the columns of ds1 Actual result: Error occurs after select the ds1 and no columns list Error log: java.lang.ClassCastException: org.eclipse.jface.wizard.WizardDialog at org.eclipse.birt.report.designer.data.ui.dataset.JointDataSetPage.selectionChanged(JointDataSetPage.java:553) at org.eclipse.jface.viewers.Viewer$2.run(Viewer.java:162) at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:37) at org.eclipse.core.runtime.Platform.run(Platform.java:850) at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:46) at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:193) at org.eclipse.jface.viewers.Viewer.fireSelectionChanged(Viewer.java:160) at org.eclipse.jface.viewers.StructuredViewer.updateSelection(StructuredViewer.java:2039) at org.eclipse.jface.viewers.StructuredViewer.handleSelect(StructuredViewer.java:1138) at org.eclipse.jface.viewers.StructuredViewer$4.widgetSelected(StructuredViewer.java:1164) at org.eclipse.jface.util.OpenStrategy.fireSelectionEvent(OpenStrategy.java:227)
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/data/ui/util/DataSetProvider.java
*/
	public static IConfigurationElement findDataSourceElement(
			String dataSourceType )
	{
		assert ( dataSourceType != null );
		
		IConfigurationElement element = (IConfigurationElement) htDataSourceExtensions.get( dataSourceType );
		if ( element == null )
		{
			IConfigurationElement[] elements = Platform.getExtensionRegistry( )
					.getConfigurationElementsFor( "org.eclipse.birt.report.designer.ui.odadatasource" );
			for ( int n = 0; n < elements.length; n++ )
			{
				if ( elements[n].getAttribute( "id" ).equals( dataSourceType ) ) 
				{
					element = elements[n];
					htDataSourceExtensions.put( dataSourceType, element );
					break;
				}
			}
			elements = Platform.getExtensionRegistry( )
					.getConfigurationElementsFor( "org.eclipse.datatools.connectivity.oda.design.ui.dataSource" );
			for ( int n = 0; n < elements.length; n++ )
			{
				if ( elements[n].getAttribute( "id" ).equals( dataSourceType ) ) 
				{
					element = elements[n];
					htDataSourceExtensions.put( dataSourceType, element );
					break;
				}