Bug 135207 parameter dialog is not displayed when drill through to a PDF report that contains parameter with no default value
steps to reproduce: - create 1st report - add a report parameter (no default value) - create 2nd report - add a label "link" - edit hyperlink property (type: drill-through, target report format: PDF) - preview 1st report - click on "link" expected behavior: - parameter dialog should be displayed - target report is rendered in PDF format actual behavior: - "Some required parameter values are not set or set to incompatible data type." was displayed instead.
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/servlet/ViewerServlet.java
* <td>required</td>
 * </tr>
 * <tr>
 * <td>__format</td>
 * <td>The output format</td>
 * <td>html or pdf</td>
 * <td>optional, default to html</td>
 * </tr>
 * <tr>
 * <td>__locale</td>
 * <td>Report locale</td>
 * <td>Java locale value such as en or ch-zh.</td>
 * <td>optional, default to JVM locale</td>
 * </tr>
 * <tr>
 * <td>__page</td>
 * <td>Report page number</td>
 * <td>Report page to be viewed.</td>
 * <td>optional, default to 0</td>
 * </tr>
 * <tr>
 * <td><i>reportParam</i></td>
 * <td>User defined report parameter.</td>
 * <td>As specified in the report design.</td>
 * <td>As specified in the report design.</td>
 * </tr>
 * </table>
 * <p>
 */
public class ViewerServlet extends BirtSoapMessageDispatcherServlet