Bug 201205 Exception occurs in dataset preview when IN filter contains a blank value[0802]
Description: Exception occurs in dataset preview when IN filter contains a blank value[0802] Build number: 2.2.1.v20070827-0630 Steps to reproduce: 1, New a sampleDB customer dataset 2, New a filter and operator is IN 3, Specify a blank value and add 4, Preview in dataset Expected result: The preview should be successful and no exception Actual result: Exception occurs Error log: org.eclipse.birt.report.designer.core.runtime.GUIException: Caused by java.lang.reflect.InvocationTargetException. at org.eclipse.birt.report.designer.core.runtime.GUIException.createGUIException(GUIException.java:76) at org.eclipse.birt.report.designer.internal.ui.util.ExceptionHandler.handle(ExceptionHandler.java:169) at org.eclipse.birt.report.designer.internal.ui.util.ExceptionHandler.handle(ExceptionHandler.java:150) at org.eclipse.birt.report.designer.internal.ui.util.ExceptionHandler.handle(ExceptionHandler.java:89) at org.eclipse.birt.report.designer.data.ui.dataset.ResultSetPreviewPage.updateResultsProcess(ResultSetPreviewPage.java:515) at org.eclipse.birt.report.designer.data.ui.dataset.ResultSetPreviewPage.runUpdateResults(ResultSetPreviewPage.java:274) at org.eclipse.birt.report.designer.data.ui.dataset.ResultSetPreviewPage.access$1(ResultSetPreviewPage.java:244) at org.eclipse.birt.report.designer.data.ui.dataset.ResultSetPreviewPage$4.runInUIThread(ResultSetPreviewPage.java:237)
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/script/ScriptEvalUtil.java
* Javascript expressions themselves).<br>
	 * Both op1 and op2 will be encapsulated to ExprTextAndValue type to show
	 * specific message in case anything goes wrong, they are assumed not to be
	 * null as well.
	 * <p>
	 * The basic rule for comparison: obj will always be considered as the
	 * default data type,i.e. obj, op1 and op2 will be formatted to the superset
	 * of obj (or Double if obj is numeric)on the condition they are comparable.<br>
	 * e.g.<br>
	 * obj: Integer=>obj, op1 and op2 will be formatted to Double.<br>
	 * obj: Timestamp=>obj, op1 and op2 will be formatted to Date.<br>
	 * obj: Boolean=>obj and op1 will be formatted to Boolean.<br>
	 * obj: String=>obj, op1 and op2 will remain the same
	 * 
	 * @param obj
	 * @param operator
	 * @param Op1
	 * @param Op2
	 * @return
	 * @throws DataException
	 */
	public static Object evalConditionalExpr( Object obj, int operator,
			Object Op1, Object Op2 ) throws DataException
	{
		return evalConditionalExpr( obj, operator, new Object[]{
				Op1, Op2
		} );
	}
	
	/**