JBR-6984 Fix BoxLayout/NPECheckRequests test

It was initially written and tested on Linux, but it turns out that
on other systems validate() can be called in between init() and start()
calls, which would break the test even though BoxLayout isn't broken.

test/jdk/javax/swing/BoxLayout/NPECheckRequests/NPECheckRequests.java

@@ -31,18 +31,33 @@
 import java.awt.BorderLayout;
 import java.lang.reflect.InvocationTargetException;
 import java.awt.Dimension;
+import java.util.logging.Logger;
 import javax.swing.BoxLayout;
 import javax.swing.JFrame;
 import javax.swing.JPanel;
 import javax.swing.SwingUtilities;
 
 public class NPECheckRequests {
+    private static final Logger LOG = Logger.getLogger(NPECheckRequests.class.getName());
     JFrame frame;
     JPanel p;
     BrokenComponent foo;
 
     public void init() {
-        frame = new JFrame();
+        frame = new JFrame() {
+            @Override
+            public void validate() {
+                try {
+                    super.validate();
+                } catch (BrokenComponentException e) {
+                    if (foo.broken) {
+                        LOG.info("Caught BrokenComponentException in JFrame.validate() - expected, ignored");
+                    } else {
+                        throw e;
+                    }
+                }
+            }
+        };
         p = new JPanel();
         BoxLayout boxLayout = new BoxLayout(p, BoxLayout.X_AXIS);
         p.setLayout(boxLayout);
@@ -52,8 +67,8 @@ public void init() {
         frame.add(p, BorderLayout.CENTER);
         try {
             frame.pack();
-        } catch (RuntimeException ignored) {
-            // our broken component threw an exception
+        } catch (BrokenComponentException ignored) {
+            LOG.info("Caught BrokenComponentException in JFrame.pack() - expected, ignored");
         }
     }
 
@@ -77,10 +92,16 @@ private class BrokenComponent extends JPanel {
         @Override
         public Dimension getPreferredSize() {
             if (broken) {
-                throw new RuntimeException("Broken component");
+                throw new BrokenComponentException();
             }
             return super.getPreferredSize();
         }
     }
 
+    private static class BrokenComponentException extends RuntimeException {
+        BrokenComponentException() {
+            super("Broken component");
+        }
+    }
+
 }