MID-9998 Fix stale page recovery after view-source

gui/admin-gui/src/main/java/com/evolveum/midpoint/web/security/LoggingRequestCycleListener.java

@@ -9,6 +9,8 @@
 import org.apache.wicket.Application;
 import org.apache.wicket.core.request.handler.PageProvider;
 import org.apache.wicket.core.request.handler.RenderPageRequestHandler;
+import org.apache.wicket.core.request.handler.RenderPageRequestHandler.RedirectPolicy;
+import org.apache.wicket.core.request.mapper.StalePageException;
 import org.apache.wicket.request.IRequestHandler;
 import org.apache.wicket.request.Url;
 import org.apache.wicket.request.component.IRequestablePage;
@@ -49,6 +51,14 @@ public IRequestHandler onException(RequestCycle cycle, Exception ex) {
             REQUEST_LOGGER.trace("REQUEST CYCLE: Exception: {}, handler {}", ex,
                     WebComponentUtil.debugHandler(cycle.getActiveRequestHandler()), ex);
         }
+        if (ex instanceof StalePageException stalePageException) {
+            // Wicket uses this exception for stale render-count recovery, e.g. after browser view-source.
+            // Do not convert it to PageError/500, recover by re-rendering the stale page.
+            LOGGER.debug("Recovering stale Wicket page request by re-rendering page {}", stalePageException.getPage());
+            return new RenderPageRequestHandler(
+                    new PageProvider(stalePageException.getPage()),
+                    RedirectPolicy.ALWAYS_REDIRECT);
+        }
         LoggingUtils.logUnexpectedException(LOGGER, "Error occurred during page rendering", ex);
         return new RenderPageRequestHandler(new PageProvider(new PageError(ex)));
     }
@@ -136,4 +146,3 @@ public void onUrlMapped(RequestCycle cycle, IRequestHandler handler, Url url) {
         }
     }
 }
-

gui/admin-gui/src/test/java/com/evolveum/midpoint/web/LoggingRequestCycleListenerTest.java

@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2010-2026 Evolveum and contributors
+ *
+ * This work is dual-licensed under the Apache License 2.0
+ * and European Union Public License. See LICENSE file for details.
+ */
+
+package com.evolveum.midpoint.web;
+
+import com.evolveum.midpoint.web.security.LoggingRequestCycleListener;
+import org.apache.wicket.core.request.handler.RenderPageRequestHandler;
+import org.apache.wicket.core.request.handler.RenderPageRequestHandler.RedirectPolicy;
+import org.apache.wicket.core.request.mapper.StalePageException;
+import org.apache.wicket.markup.html.WebPage;
+import org.apache.wicket.request.IRequestHandler;
+import org.apache.wicket.util.tester.WicketTester;
+import org.testng.Assert;
+import org.testng.annotations.Test;
+
+/**
+ * Tests exception handling behavior in {@link LoggingRequestCycleListener}.
+ */
+public class LoggingRequestCycleListenerTest {
+
+    /**
+     * MID-9998: Verifies that Wicket stale page recovery, e.g. after browser
+     * view-source, is handled by re-rendering the stale page instead of being
+     * converted to the error page / HTTP 500.
+     */
+    @Test
+    public void testStalePageExceptionIsRecoveredInsteadOfConvertedToPageError() {
+        WicketTester tester = new WicketTester();
+        try {
+            LoggingRequestCycleListener listener = new LoggingRequestCycleListener(tester.getApplication());
+            TestPage page = new TestPage();
+
+            IRequestHandler handler = listener.onException(null, new StalePageException(page));
+
+            Assert.assertTrue(handler instanceof RenderPageRequestHandler);
+
+            RenderPageRequestHandler renderHandler = (RenderPageRequestHandler) handler;
+            Assert.assertSame(renderHandler.getPage(), page);
+            Assert.assertSame(renderHandler.getRedirectPolicy(), RedirectPolicy.ALWAYS_REDIRECT);
+        } finally {
+            tester.destroy();
+        }
+    }
+
+    private static class TestPage extends WebPage {
+    }
+}

gui/admin-gui/testng-unit.xml

@@ -14,6 +14,7 @@
             <class name="com.evolveum.midpoint.web.TestXmlGregorianCalendarModel"/>
             <class name="com.evolveum.midpoint.gui.SelectableBeanDataProviderCountCacheTest"/>
             <class name="com.evolveum.midpoint.gui.FocusDefinitionsMappingProviderTest"/>
+            <class name="com.evolveum.midpoint.web.LoggingRequestCycleListenerTest"/>
         </classes>
     </test>
 </suite>

release-notes.adoc

@@ -140,6 +140,7 @@ Overall, midPoint 4.10 opens up the world of identity management and governance
 * Fixed missing .zip extension when downloading tracing report files. See bug:MID-11096[]
 * Fixed resource wizard mapping property autocomplete to find partial matches regardless of letter case. See bug:MID-10415[]
 * Fixed missing input variable in resource activation existence mappings. See bug:MID-10905[]
+* Fixed stale page recovery after viewing page source causing internal server error. See bug:MID-9998[]
 
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