Bug 187162 [Regression]NPE throws out when open a dataset which reference datasource has no driver[07]
Description: NPE throws out when open a dataset which reference datasource has no driver[07] Build number: 2.2.0.v20070516-0630 Steps to reproduce: 1, open a dataset makesure the datasource has no driver 2, Close all the warning dialog and the dataset dialog 3, Check the error log Expected result: No NPE throws out Actual result: NPE throws out Error log: java.lang.NullPointerException at org.eclipse.birt.report.data.oda.jdbc.ui.editors.SQLDataSetEditorPage.refreshPage(SQLDataSetEditorPage.java:1376) at org.eclipse.birt.report.data.oda.jdbc.ui.editors.SQLDataSetEditorPage.initializeControl(SQLDataSetEditorPage.java:272) at org.eclipse.birt.report.data.oda.jdbc.ui.editors.SQLDataSetEditorPage.createPageCustomControl(SQLDataSetEditorPage.java:191) at org.eclipse.datatools.connectivity.oda.design.ui.wizards.DataSetWizardPage.createControl(DataSetWizardPage.java:123) at org.eclipse.datatools.connectivity.oda.design.internal.ui.DataSetEditorPageCore.createContents(DataSetEditorPageCore.java:73) at org.eclipse.jface.preference.PreferencePage.createControl(PreferencePage.java:233) at org.eclipse.birt.report.designer.data.ui.dataset.PropertyPageWrapper.createPageControl(PropertyPageWrapper.java:45) at org.eclipse.birt.report.designer.data.ui.property.PropertyNode.createPageControl(PropertyNode.java:238) at org.eclipse.birt.report.designer.data.ui.property.AbstractPropertyDialog.showPage(AbstractPropertyDialog.java:442) at org.eclipse.birt.report.designer.data.ui.property.AbstractPropertyDialog.showSelectionPage(AbstractPropertyDialog.java:346) at org.eclipse.birt.report.designer.data.ui.dataset.DataSetEditor.showSelectionPage(DataSetEditor.java:720) at org.eclipse.birt.report.designer.data.ui.property.AbstractPropertyDialog$2.run(AbstractPropertyDialog.java:304)
data/org.eclipse.birt.report.data.oda.jdbc.ui/src/org/eclipse/birt/report/data/oda/jdbc/ui/editors/SQLDataSetEditorPage.java
availableDbObjectsTree = new Tree( tablescomposite, SWT.BORDER
				| SWT.MULTI );
		{
			GridData data = new GridData( GridData.FILL_BOTH );
			data.grabExcessHorizontalSpace = true;
			data.grabExcessVerticalSpace = true;
			data.heightHint = 150;
			availableDbObjectsTree.setLayoutData( data );
		}
		availableDbObjectsTree.addMouseListener( new MouseAdapter( ) {
			public void mouseDoubleClick( MouseEvent e )
			{
				populateEventData( e );
				insertText( (String) e.data );
			}
		} );
		availableDbObjectsTree.addSelectionListener( new SelectionAdapter( ) {
			public void widgetSelected( SelectionEvent event )
			{
				if ( event.widget.getClass( ) != null )
					handleAvailabeTreeSelection( );
			}
			private void handleAvailabeTreeSelection( )
			{
				TreeItem items[] = availableDbObjectsTree.getSelection( );
				for ( int i = 0; i < items.length; i++ )
				{
					if ( items[i].getGrayed( ) )
					{
						availableDbObjectsTree.setRedraw( false );