ZK-5730: Harden smartUpdate to check for null desktop or null webapp

zk/src/main/java/org/zkoss/zk/ui/AbstractPage.java

@@ -1,9 +1,9 @@
 /* AbstractPage.java
 
 	Purpose:
-		
+
 	Description:
-		
+
 	History:
 		Sun Oct 26 17:42:22     2008, Created by tomyeh
 
@@ -233,6 +233,7 @@ public void removeComponents() {
 	}
 
 	public void destroy() {
+		removeComponents(); // ZK-5730
 		_firstRoot = null;
 		_nRoot = 0;
 		_fellows = new HashMap<String, Component>(2); //not clear() since # of fellows might huge

zkdoc/release-note

@@ -105,6 +105,7 @@ Feb 27, 2024
   ZK-5636: fail to toggle grid's detail on iPad/iPhone
   ZK-5650: cannot upload an image under websocket
   ZK-5633: Client mvvm crashes a browser when model is large
+  ZK-5730: Harden smartUpdate to check for null desktop or null webapp
 
 * Upgrade Notes
   + Upgrade commons-fileupload to commons-fileupload2-javax 2.0.0-M2 and commons-io to 2.13.0 to support jakarta-friendly uploads

zktest/src/main/java/org/zkoss/zktest/test2/B101_ZK_5730Composer.java

@@ -0,0 +1,58 @@
+/* B101_ZK_5730Composer.java
+
+	Purpose:
+
+	Description:
+
+	History:
+		12:10 PM 2024/10/9, Created by jumperchen
+
+Copyright (C) 2024 Potix Corporation. All Rights Reserved.
+*/
+package org.zkoss.zktest.test2;
+
+import org.zkoss.zk.ui.Component;
+import org.zkoss.zk.ui.Sessions;
+import org.zkoss.zk.ui.event.Events;
+import org.zkoss.zk.ui.http.SimpleSession;
+import org.zkoss.zk.ui.select.SelectorComposer;
+import org.zkoss.zk.ui.select.annotation.Listen;
+import org.zkoss.zk.ui.select.annotation.Wire;
+import org.zkoss.zul.Div;
+import org.zkoss.zul.Grid;
+import org.zkoss.zul.ListModelList;
+
+/**
+ * @author jumperchen
+ */
+public class B101_ZK_5730Composer extends SelectorComposer {
+
+	@Wire private Grid grid;
+	private Div rootDiv;
+	private ListModelList model = new ListModelList();
+
+	@Override
+	public void doAfterCompose(Component comp) throws Exception {
+		super.doAfterCompose(comp);
+		rootDiv = (Div) comp;
+		grid.setModel(model);
+	}
+
+	@Listen(Events.ON_CLICK + "=#logout")
+	public void logout() {
+		((SimpleSession)Sessions.getCurrent()).invalidateNow();
+	}
+
+	@Listen(Events.ON_CLICK + "=#op2")
+	public void longOp() {
+		fakeOperation(3);
+		grid.addSclass("success");
+	}
+
+	static public void fakeOperation(int seconds) {
+		long endTime = System.currentTimeMillis() + seconds * 1000;
+		while (System.currentTimeMillis() < endTime) {
+			// Just a busy-wait. In real scenarios, this could be some meaningful computation.
+		}
+	}
+}

zktest/src/main/java/org/zkoss/zktest/test2/B101_ZK_5730_1Composer.java

@@ -0,0 +1,59 @@
+/* B101_ZK_5730_1Composer.java
+
+	Purpose:
+
+	Description:
+
+	History:
+		12:32 PM 2024/10/9, Created by jumperchen
+
+Copyright (C) 2024 Potix Corporation. All Rights Reserved.
+*/
+package org.zkoss.zktest.test2;
+
+import java.util.Optional;
+
+import org.zkoss.zk.ui.Component;
+import org.zkoss.zk.ui.Desktop;
+import org.zkoss.zk.ui.Executions;
+import org.zkoss.zk.ui.event.Event;
+import org.zkoss.zk.ui.event.EventListener;
+import org.zkoss.zk.ui.event.Events;
+import org.zkoss.zk.ui.sys.PageCtrl;
+import org.zkoss.zk.ui.util.Composer;
+import org.zkoss.zul.Button;
+import org.zkoss.zul.Label;
+
+/**
+ * @author jumperchen
+ */
+public class B101_ZK_5730_1Composer implements Composer {
+	@Override
+	public void doAfterCompose(Component comp) throws Exception {
+		Desktop dt = Executions.getCurrent().getDesktop();
+		dt.enableServerPush(true);
+
+		Button button = new Button("schedule");
+		Label myLabel = new Label("my label");
+
+		comp.appendChild(button);
+		comp.appendChild(myLabel);
+
+		button.addEventListener(Events.ON_CLICK, event -> {
+			Runnable runnable = () -> {
+				System.out.println("runnable - run()");
+				myLabel.addSclass("bg-red");
+			};
+			EventListener<? super Event> executeEventListener = this::executeEventListener;
+			Executions.schedule(dt, executeEventListener, new Event("ExecuteEvent", null, runnable));
+
+			// This causes an NPE in the runnable above
+			((PageCtrl)comp.getPage()).destroy();
+		});
+
+	}
+
+	public void executeEventListener(Event event) {
+		Optional.ofNullable((Runnable)event.getData()).ifPresent(Runnable::run);
+	}
+}

zktest/src/main/webapp/test2/B101-ZK-5730-1.zul

@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<!--
+B101-ZK-5730-1.zul
+
+	Purpose:
+
+	Description:
+
+	History:
+		2024/10/9, Created by jumperchen
+
+Copyright (C) 2024 Potix Corporation. All Rights Reserved.
+
+-->
+<zk>
+	<style>
+		.z-label.bg-red {
+		background-color: red;
+		}
+	</style>
+	<div apply="org.zkoss.zktest.test2.B101_ZK_5730_1Composer"/>
+</zk>

zktest/src/main/webapp/test2/B101-ZK-5730.zul

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<!--
+B101-ZK-5730.zul
+
+	Purpose:
+
+	Description:
+
+	History:
+		2024/10/9, Created by jumperchen
+
+Copyright (C) 2024 Potix Corporation. All Rights Reserved.
+
+-->
+<zk>
+	<div apply="org.zkoss.zktest.test2.B101_ZK_5730Composer">
+		<button id="op2" label="sync long op"/>
+		<button id="logout" label="logout" />
+		<grid id="grid"></grid>
+	</div>
+</zk>

zktest/src/main/webapp/test2/config.properties

@@ -3150,6 +3150,7 @@ B90-ZK-4431.zul=A,E,Multislider
 ##zats##B101-ZK-5799.zul=A,E,ClientMVVM,pdfviewer,zonejs
 ##manually##B101-ZK-5801.zul=A,E,ClientMVVM,Apply
 ##zats##B101-ZK-5546.zul=A,E,Websocket,Session,Timeout
+##zats##B101-ZK-5730.zul=A,E,NullPointerException,Desktop,Page,Session,Timeout,Destroy,SmartUpdate
 
 ##
 # Features - 3.0.x version

zktest/src/test/java/org/zkoss/zktest/zats/test2/B101_ZK_5730Test.java

@@ -0,0 +1,47 @@
+/* B101_ZK_5730Test.java
+
+	Purpose:
+
+	Description:
+
+	History:
+		12:11 PM 2024/10/9, Created by jumperchen
+
+Copyright (C) 2024 Potix Corporation. All Rights Reserved.
+*/
+package org.zkoss.zktest.zats.test2;
+
+import org.junit.jupiter.api.Test;
+import org.openqa.selenium.WindowType;
+
+import org.zkoss.test.webdriver.WebDriverTestCase;
+
+/**
+ * @author jumperchen
+ */
+public class B101_ZK_5730Test extends WebDriverTestCase {
+
+	@Test
+	public void test() {
+		connect();
+		driver.switchTo().newWindow(WindowType.TAB);
+		driver.get(getAddress() + "/test2/B101-ZK-5730.zul");
+		waitResponse();
+		Object[] windowHandles = driver.getWindowHandles().toArray();
+		driver.switchTo().window((String) windowHandles[0]);
+		click(jq("$op2"));
+		driver.switchTo().window((String) windowHandles[1]);
+		click(jq("$logout"));
+		driver.switchTo().window((String) windowHandles[0]);
+		waitResponse();
+		assertNoZKError();
+	}
+
+	@Test
+	public void testCase1() {
+		connect("/test2/B101-ZK-5730-1.zul");
+		click(jq("@button"));
+		waitResponse();
+		assertNoZKError();
+	}
+}