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
.contains( DateSetPreferencePage.SCHEMAS_PREFETCH_CONFIG ) )
		{
			JdbcPlugin.getDefault( )
					.getPluginPreferences( )
					.setValue( DateSetPreferencePage.SCHEMAS_PREFETCH_CONFIG,
							ENABLED );
		}
	}
	/**
	 * Creates the composite, for displaying the list of available db objects
	 * 
	 * @param parent
	 */
	private void createTableSelectionComposite( Composite parent )
	{
		Composite tablescomposite = new Composite( parent, SWT.NONE );
		GridLayout layout = new GridLayout( );
		tablescomposite.setLayout( layout );
		{
			GridData data = new GridData( GridData.FILL_BOTH );
			data.grabExcessVerticalSpace = true;
			tablescomposite.setLayoutData( data );
		}
		
		Label dataSourceLabel = new Label( tablescomposite, SWT.LEFT );
		dataSourceLabel.setText( JdbcPlugin.getResourceString( "tablepage.label.availableItems" ) );
		{
			GridData data = new GridData( );
			dataSourceLabel.setLayoutData( data );
		}