JBR-7851 Wayland: IDEA crashes if Esc is pressed to close Diff window

src/java.desktop/unix/classes/sun/awt/wl/WLComponentPeer.java

@@ -1038,13 +1038,23 @@ public class WLComponentPeer implements ComponentPeer {
 
     final void activate() {
         // "The serial can come from an input or focus event."
-        long serial = WLToolkit.getInputState().keyboardEnterSerial();
+        long serial = WLToolkit.getInputState().keyboardEnterSerial(); // a focus event
+        if (serial == 0) { // may have just left one surface and not yet entered another
+            serial = WLToolkit.getInputState().keySerial(); // an input event
+        }
+        if (serial == 0) {
+            // The pointer button serial seems to not work with Mutter, but may work
+            // with other implementations, so let's keep it as an input event serial
+            // of the last resort.
+            serial = WLToolkit.getInputState().pointerButtonSerial();
+        }
         long surface = WLToolkit.getInputState().surfaceForKeyboardInput();
         if (serial != 0) {
-            performLocked(() -> nativeActivate(serial, nativePtr, surface));
+            long finalSerial = serial;
+            performLocked(() -> nativeActivate(finalSerial, nativePtr, surface));
         } else {
             if (log.isLoggable(Level.WARNING)) {
-                log.warning("activate() aborted due to missing keyboard enter event serial");
+                log.warning("activate() aborted due to missing input or focus event serial");
             }
         }
     }

src/java.desktop/unix/classes/sun/awt/wl/WLInputState.java

@@ -186,6 +186,27 @@ record WLInputState(WLPointerEvent eventWithSurface,
                 isPointerOverSurface);
     }
 
+    public WLInputState updatedFromUnregisteredSurface(long surfacePtr) {
+        if (surfaceForKeyboardInput == surfacePtr) {
+            // When a window is hidden, we don't receive the keyboard.leave event, but the surface
+            // becomes stale and its use dangerous, so must clear it out.
+            return new WLInputState(
+                    eventWithSurface,
+                    pointerEnterSerial,
+                    pointerButtonSerial,
+                    keyboardEnterSerial,
+                    keySerial,
+                    eventWithTimestamp,
+                    eventWithCoordinates,
+                    pointerButtonPressedEvent,
+                    modifiers,
+                    0,
+                    isPointerOverSurface);
+        } else {
+            return this;
+        }
+    }
+
     public WLInputState resetPointerState() {
         return new WLInputState(
                 eventWithSurface,

src/java.desktop/unix/classes/sun/awt/wl/WLToolkit.java

@@ -441,6 +441,8 @@ public class WLToolkit extends UNIXToolkit implements Runnable {
         synchronized (wlSurfaceToComponentMap) {
             wlSurfaceToComponentMap.remove(wlSurfacePtr);
         }
+
+        inputState = inputState.updatedFromUnregisteredSurface(wlSurfacePtr);
     }
 
     static WLComponentPeer componentPeerFromSurface(long wlSurfacePtr) {

test/jdk/TEST.groups

@@ -818,6 +818,7 @@ jdk_since_checks = \
 jdk_awt_wayland = \
     :jdk_awt \
     jb/java/awt/wayland \
+    jb/java/awt/Focus/ActivateAfterHide.java \
     -com/apple/eawt \
     -com/apple/laf \
     -sun/awt \

test/jdk/jb/java/awt/Focus/ActivateAfterHide.java

@@ -0,0 +1,72 @@
+/*
+ * Copyright 2024 JetBrains s.r.o.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+
+import javax.swing.JButton;
+import javax.swing.JFrame;
+import javax.swing.JLabel;
+import javax.swing.SwingUtilities;
+import java.awt.BorderLayout;
+import java.util.concurrent.CountDownLatch;
+
+/**
+ * @test
+ * @summary Verifies that toFront() called immediately following setVisible(false)
+ * does not terminate the application
+ * @key headful
+ * @run main/othervm/manual ActivateAfterHide
+ */
+
+public class ActivateAfterHide {
+    static JFrame frame1;
+    static JFrame frame2;
+    static CountDownLatch latch = new CountDownLatch(1);
+
+    public static void main(String[] args) throws Exception {
+        SwingUtilities.invokeAndWait(ActivateAfterHide::createAndShowUI);
+        latch.await();
+    }
+
+    static void createAndShowUI() {
+        frame1 = new JFrame("ActivateAfterHide Frame 1");
+        frame1.setSize(300, 200);
+        frame1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+        JButton passButton = new JButton("Pass");
+        passButton.addActionListener(e -> {latch.countDown();});
+        frame1.add(new JLabel("<html><p>Press the Close button in the second window.</p>" +
+                "<p>Test PASSES if this frame is still visible afterwards and FAILS if no UI is visible.</p></html>"), BorderLayout.NORTH);
+        frame1.add(passButton, BorderLayout.SOUTH);
+        frame1.setVisible(true);
+
+        frame2 = new JFrame("ActivateAfterHide Frame 2");
+        frame2.setSize(300, 200);
+        JButton closeButton = new JButton("Close");
+        closeButton.addActionListener(e -> {
+            frame2.dispose();
+            frame1.toFront();
+        });
+        frame2.getContentPane().add(closeButton);
+        frame2.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+        frame2.setVisible(true);
+    }
+}