Bug 206861 The data set cache should handle IOException and the cancel request from customer
The data set data will be saved into disk file in the first query and it will be loaded in the later time. The processing of write disk file may be cancelled by customer request or IOException. Using the data from the bad file will cause error.
data/org.eclipse.birt.data.tests/test/org/eclipse/birt/data/engine/binding/DataSetCacheTest.java
new ScriptExpression( "dataSetRow.CITY" ) );
		subqueryDefn.setApplyOnGroupFlag( false );
		qd.addSubquery( subqueryDefn );
		
		IQueryResults qr = myDataEngine.prepare( qd, appContextMap )
				.execute( null );
		assertTrue( qr.getResultMetaData( ) != null );
		return qr.getResultIterator( );
	}
	/**
	 * @throws BirtException 
	 * 
	 */
	public void testScriptedCache( ) throws BirtException
	{
		genCache2( );
		useCache2( );
	}
	/**
	 * @throws BirtException
	 */
	private void genCache2( ) throws BirtException
	{
		DataEngineContext context = DataEngineContext.newInstance( DataEngineContext.DIRECT_PRESENTATION,
				null,
				null,
				null );
		context.setCacheOption( DataEngineContext.CACHE_USE_ALWAYS, 4 );
		DataEngine myDataEngine2 = DataEngine.newDataEngine( context );
		IResultIterator ri = getResultIterator2( myDataEngine2 );