Different fix for mozilla#48

anba · anba · commit 76adbd7e861c · 2012-06-04T11:03:39.000+02:00
diff --git a/src/org/mozilla/javascript/ScriptableObject.java b/src/org/mozilla/javascript/ScriptableObject.java
@@ -1294,6 +1294,15 @@ static <T extends Scriptable> BaseFunction buildClassCtor(
         Scriptable proto = (Scriptable) protoCtor.newInstance(ScriptRuntime.emptyArgs);
         String className = proto.getClassName();
 
+        // check for possible redefinition
+        Object existing = getProperty(getTopLevelScope(scope), className);
+        if (existing instanceof BaseFunction) {
+            Object existingProto = ((BaseFunction)existing).getPrototypeProperty();
+            if (clazz.isInstance(existingProto)) {
+                return (BaseFunction)existing;
+            }
+        }
+
         // Set the prototype's prototype, trying to map Java inheritance to JS
         // prototype-based inheritance if requested to do so.
         Scriptable superProto = null;
diff --git a/testsrc/org/mozilla/javascript/tests/DefineClassMapInheritance.java b/testsrc/org/mozilla/javascript/tests/DefineClassMapInheritance.java
@@ -0,0 +1,51 @@
+package org.mozilla.javascript.tests;
+
+import static org.junit.Assert.*;
+
+import java.lang.reflect.InvocationTargetException;
+
+import org.junit.Test;
+import org.mozilla.javascript.Context;
+import org.mozilla.javascript.ScriptableObject;
+
+@SuppressWarnings("serial")
+public class DefineClassMapInheritance {
+
+    public static class Food extends ScriptableObject {
+        @Override
+        public String getClassName() {
+            return getClass().getSimpleName();
+        }
+    }
+
+    public static class Fruit extends Food {
+    }
+
+    public static class Vegetable extends Food {
+    }
+
+    @Test
+    public void test() throws IllegalAccessException, InstantiationException,
+            InvocationTargetException {
+        Context cx = Context.enter();
+        try {
+            ScriptableObject scope = cx.initStandardObjects();
+
+            // define two classes that share a parent prototype
+            ScriptableObject.defineClass(scope, Fruit.class, false, true);
+            ScriptableObject.defineClass(scope, Vegetable.class, false, true);
+
+            assertEquals(Boolean.TRUE,
+                    evaluate(cx, scope, "(new Fruit instanceof Food)"));
+            assertEquals(Boolean.TRUE,
+                    evaluate(cx, scope, "(new Vegetable instanceof Food)"));
+        } finally {
+            Context.exit();
+        }
+    }
+
+    private static Object evaluate(Context cx, ScriptableObject scope,
+            String source) {
+        return cx.evaluateString(scope, source, "<eval>", 1, null);
+    }
+}
