Bug 182673 No default value error message prompts incorrectly
Steps to reproduce: 1. New a report parameter; 2. Choose control type as Combo; 3. Choose parameter as dynamic type; Expected result: As the isRequired is false by default, parameter's default value can be null value. There should be no error message about no default value prompt. Actual result; Error messages prompts
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ParameterDialog.java
package org.eclipse.birt.report.designer.ui.dialogs;
import java.math.BigDecimal;
import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Date;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.eclipse.birt.core.data.DataTypeUtil;
import org.eclipse.birt.core.exception.BirtException;
import org.eclipse.birt.core.format.DateFormatter;
import org.eclipse.birt.core.format.NumberFormatter;
import org.eclipse.birt.core.format.StringFormatter;
import org.eclipse.birt.data.engine.api.DataEngine;
import org.eclipse.birt.data.engine.api.DataEngineContext;
import org.eclipse.birt.data.engine.api.IPreparedQuery;
import org.eclipse.birt.data.engine.api.IQueryDefinition;
import org.eclipse.birt.data.engine.api.IQueryResults;
import org.eclipse.birt.data.engine.api.IResultIterator;
import org.eclipse.birt.data.engine.api.querydefn.BaseQueryDefinition;
import org.eclipse.birt.data.engine.api.querydefn.ScriptExpression;
import org.eclipse.birt.report.designer.internal.ui.dialogs.BaseDialog;
import org.eclipse.birt.report.designer.internal.ui.dialogs.ImportValueDialog;
import org.eclipse.birt.report.designer.internal.ui.dialogs.SelectionChoiceDialog;
import org.eclipse.birt.report.designer.internal.ui.swt.custom.ITableAreaModifier;
import org.eclipse.birt.report.designer.internal.ui.swt.custom.TableArea;
import org.eclipse.birt.report.designer.internal.ui.util.DataUtil;
import org.eclipse.birt.report.designer.internal.ui.util.ExceptionHandler;