8039776: Introspector throws NullPointerException for subclasses' mismatched get/setter

Reviewed-by: alexsch, serb

src/share/classes/java/beans/Introspector.java

@@ -806,7 +806,7 @@ public class Introspector {
     }
 
     private static boolean isAssignable(Class<?> current, Class<?> candidate) {
-        return current == null ? candidate == null : current.isAssignableFrom(candidate);
+        return ((current == null) || (candidate == null)) ? current == candidate : current.isAssignableFrom(candidate);
     }
 
     /**

test/java/beans/Introspector/Test8039776.java

+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * 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 java.util.Set;
+import java.util.SortedSet;
+
+import static java.beans.Introspector.getBeanInfo;
+
+/*
+ * @test
+ * @bug 8039776
+ * @summary Tests that Introspector does not throw NPE
+ * @author Sergey Malenkov
+ */
+
+public class Test8039776 {
+    public static void main(String[] args) throws Exception {
+        getBeanInfo(Base.class, Object.class);
+        getBeanInfo(Child.class, Base.class);
+        getBeanInfo(Child.class, Object.class);
+    }
+
+    public static class Base {
+        private SortedSet<Object> value;
+
+        public Set<Object> getValue() {
+            return this.value;
+        }
+
+        public void setValue(SortedSet<Object> value) {
+            this.value = value;
+        }
+    }
+
+    public static class Child extends Base {
+        public Set<Object> getValue() {
+            return super.getValue();
+        }
+
+        public void setValue(SortedSet<Object> items) {
+            super.setValue(items);
+        }
+    }
+}