Fix Object.getOwnPropertyDescriptors by fixing missing scope definiti…

…ons at some places Fix handling of the parent scope in a number of places. Fixes #934, which was re-opened due to a bug in the original implementation.
mozilla · May 27, 2022 · 7a94441 · 7a94441
1 parent 50ae46c
commit 7a94441
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Showing 7 changed files with 46 additions and 8 deletions.
diff --git a/src/org/mozilla/javascript/ArrowFunction.java b/src/org/mozilla/javascript/ArrowFunction.java
@@ -23,6 +23,7 @@ public ArrowFunction(
 
         Function thrower = ScriptRuntime.typeErrorThrower(cx);
         NativeObject throwing = new NativeObject();
+        ScriptRuntime.setBuiltinProtoAndParent(throwing, scope, TopLevel.Builtins.Object);
         throwing.put("get", throwing, thrower);
         throwing.put("set", throwing, thrower);
         throwing.put("enumerable", throwing, Boolean.FALSE);

diff --git a/src/org/mozilla/javascript/BaseFunction.java b/src/org/mozilla/javascript/BaseFunction.java
@@ -509,7 +509,8 @@ protected synchronized Object setupDefaultPrototype() {
             return prototypeProperty;
         }
         NativeObject obj = new NativeObject();
-        obj.defineProperty("constructor", this, DONTENUM);
+        obj.setParentScope(getParentScope());
+
         // put the prototype property into the object now, then in the
         // wacky case of a user defining a function Object(), we don't
         // get an infinite loop trying to find the prototype.
@@ -519,6 +520,8 @@ protected synchronized Object setupDefaultPrototype() {
             // not the one we just made, it must remain grounded
             obj.setPrototype(proto);
         }
+
+        obj.defineProperty("constructor", this, DONTENUM);
         return obj;
     }
 

diff --git a/src/org/mozilla/javascript/BoundFunction.java b/src/org/mozilla/javascript/BoundFunction.java
@@ -39,6 +39,7 @@ public BoundFunction(
 
         Function thrower = ScriptRuntime.typeErrorThrower(cx);
         NativeObject throwing = new NativeObject();
+        ScriptRuntime.setBuiltinProtoAndParent(throwing, scope, TopLevel.Builtins.Object);
         throwing.put("get", throwing, thrower);
         throwing.put("set", throwing, thrower);
         throwing.put("enumerable", throwing, Boolean.FALSE);

diff --git a/src/org/mozilla/javascript/Delegator.java b/src/org/mozilla/javascript/Delegator.java
@@ -225,7 +225,7 @@ public Object call(Context cx, Scriptable scope, Scriptable thisObj, Object[] ar
 
     /**
      * Note that if the <code>delegee</code> is <code>null</code>, this method creates a new
-     * instance of the Delegator itself rathert than forwarding the call to the <code>delegee</code>
+     * instance of the Delegator itself rather than forwarding the call to the <code>delegee</code>
      * . This permits the use of Delegator prototypes.
      *
      * @param cx the current Context for this thread
@@ -243,7 +243,7 @@ public Scriptable construct(Context cx, Scriptable scope, Object[] args) {
             Delegator n = newInstance();
             Scriptable delegee;
             if (args.length == 0) {
-                delegee = new NativeObject();
+                delegee = cx.newObject(scope);
             } else {
                 delegee = ScriptRuntime.toObject(cx, scope, args[0]);
             }

diff --git a/src/org/mozilla/javascript/NativeObject.java b/src/org/mozilla/javascript/NativeObject.java
@@ -160,7 +160,7 @@ public Object execIdCall(
                         return f.construct(cx, scope, args);
                     }
                     if (args.length == 0 || args[0] == null || Undefined.isUndefined(args[0])) {
-                        return new NativeObject();
+                        return cx.newObject(scope);
                     }
                     return ScriptRuntime.toObject(cx, scope, args[0]);
                 }

diff --git a/src/org/mozilla/javascript/ScriptableObject.java b/src/org/mozilla/javascript/ScriptableObject.java
@@ -2654,8 +2654,7 @@ private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundE
     protected ScriptableObject getOwnPropertyDescriptor(Context cx, Object id) {
         Slot slot = querySlot(cx, id);
         if (slot == null) return null;
-        Scriptable scope = getParentScope();
-        return slot.getPropertyDescriptor(cx, (scope == null ? this : scope));
+        return slot.getPropertyDescriptor(cx, this);
     }
 
     protected Slot querySlot(Context cx, Object id) {

diff --git a/testsrc/org/mozilla/javascript/tests/es6/NativeObjectTest.java b/testsrc/org/mozilla/javascript/tests/es6/NativeObjectTest.java
@@ -13,6 +13,7 @@
 import java.util.Map;
 import org.junit.Test;
 import org.mozilla.javascript.Context;
+import org.mozilla.javascript.Scriptable;
 import org.mozilla.javascript.ScriptableObject;
 import org.mozilla.javascript.tests.Utils;
 
@@ -38,7 +39,8 @@ public void testAssignPropertyGetter() {
 
     @Test
     public void testAssignOneParameter() {
-        evaluateAndAssert("var obj = {};" + "res = Object.assign(obj);" + "res === obj;", true);
+        evaluateAndAssert(
+                "var obj = {};" + "res = Object.assign(obj);" + "res === obj;", Boolean.TRUE);
     }
 
     @Test
@@ -264,7 +266,39 @@ public void testFromEntriesOnArray() {
         evaluateAndAssert("Object.fromEntries(Object.entries(['x','y','z']))", map);
     }
 
-    private void evaluateAndAssert(final String script, final Object expected) {
+    @Test
+    public void issue943() {
+        evaluateAndAssert(
+                "var foo = function e() {}\n"
+                        + "var fooProto = foo.prototype;\n"
+                        + "var descProp = Object.getOwnPropertyDescriptor(fooProto, 'constructor');"
+                        + "descProp.hasOwnProperty('value');\n",
+                Boolean.TRUE);
+    }
+
+    @Test
+    public void issue943Realm() {
+        final String script =
+                "realm.Object.getOwnPropertyDescriptor(realm.Object, 'getOwnPropertyDescriptor').__proto__ === ({}).__proto__;";
+
+        String[] prefixes = {"", "'use strict;'\n"};
+        for (final String prefix : prefixes) {
+            Utils.runWithAllOptimizationLevels(
+                    cx -> {
+                        cx.setLanguageVersion(Context.VERSION_ES6);
+                        ScriptableObject scope = cx.initStandardObjects();
+
+                        Scriptable realm = cx.initStandardObjects();
+                        scope.put("realm", scope, realm);
+
+                        Object result = cx.evaluateString(scope, prefix + script, "test", 1, null);
+                        assertEquals(Boolean.FALSE, result);
+                        return null;
+                    });
+        }
+    }
+
+    private static void evaluateAndAssert(final String script, final Object expected) {
         String[] prefixes = {"", "'use strict;'\n"};
         for (final String prefix : prefixes) {
             Utils.runWithAllOptimizationLevels(