1. Fixing http://bugzilla.mozilla.org/show_bug.cgi?id=102093 :

In NativeCall constructor adds argument object only if there is no parameters with this name and similarly do not set arguments to undefined if the function has "var arguments".

2. Split NativeCall into NativeCall and NativeCallPrototype to allow for smaller activation objects with faster property access.

js/rhino/src/org/mozilla/javascript/NativeCall.java

@@ -43,14 +43,15 @@ package org.mozilla.javascript;
  * @see org.mozilla.javascript.Arguments
  * @author Norris Boyd
  */
-public final class NativeCall extends IdScriptable {
-
-    static void init(Context cx, Scriptable scope, boolean sealed) {
-        NativeCall obj = new NativeCall();
-        obj.prototypeFlag = true;
-        obj.addAsPrototype(MAX_PROTOTYPE_ID, cx, scope, sealed);
+public final class NativeCall extends ScriptableObject
+{
+    static void init(Context cx, Scriptable scope, boolean sealed)
+    {
+        new NativeCallPrototype(cx, scope, sealed);
     }
 
+    NativeCall() { }
+
     NativeCall(Context cx, Scriptable scope, NativeFunction funObj,
                Scriptable thisObj, Object[] args)
     {
@@ -76,36 +77,29 @@ public final class NativeCall extends IdScriptable {
             }
         }
 
-        // initialize "arguments" property
-        super.put("arguments", this, new Arguments(this));
+        // initialize "arguments" property but only if it was not overriden by
+        // the parameter with the same name
+        if (!super.has("arguments", this)) {
+            super.put("arguments", this, new Arguments(this));
+        }
 
         if (argNames != null) {
             for (int i = funObj.argCount; i != argNames.length; i++) {
-                super.put(argNames[i], this, Undefined.instance);
+                String name = argNames[i];
+                if (!super.has(name, this)) {
+                    super.put(name, this, Undefined.instance);
+                }
             }
         }
     }
 
-    private NativeCall() {
-    }
-
-    public String getClassName() {
+    public String getClassName()
+    {
         return "Call";
     }
 
-    private static Object jsConstructor(Context cx, Object[] args,
-                                        Function ctorObj, boolean inNewExpr)
+    NativeCall getActivation(Function f)
     {
-        if (!inNewExpr) {
-            throw Context.reportRuntimeError1("msg.only.from.new", "Call");
-        }
-        ScriptRuntime.checkDeprecated(cx, "Call");
-        NativeCall result = new NativeCall();
-        result.setPrototype(getObjectPrototype(ctorObj));
-        return result;
-    }
-
-    NativeCall getActivation(Function f) {
         NativeCall x = this;
         do {
             if (x.funObj == f)
@@ -115,63 +109,79 @@ public final class NativeCall extends IdScriptable {
         return null;
     }
 
-    public Function getFunctionObject() {
+    public Function getFunctionObject()
+    {
         return funObj;
     }
 
-    public Object[] getOriginalArguments() {
+    public Object[] getOriginalArguments()
+    {
         return originalArgs;
     }
 
-    public NativeCall getCaller() {
+    public NativeCall getCaller()
+    {
         return caller;
     }
 
-    public Scriptable getThisObj() {
+    public Scriptable getThisObj()
+    {
         return thisObj;
     }
 
-    public int methodArity(int methodId) {
-        if (prototypeFlag) {
-            if (methodId == Id_constructor) return 1;
-        }
+    NativeCall caller;
+    NativeFunction funObj;
+    Scriptable thisObj;
+    private Object[] originalArgs;
+}
+
+final class NativeCallPrototype extends IdScriptable
+{
+    NativeCallPrototype(Context cx, Scriptable scope, boolean sealed)
+    {
+        addAsPrototype(MAX_PROTOTYPE_ID, cx, scope, sealed);
+    }
+
+    public String getClassName()
+    {
+        return "Call";
+    }
+
+    public int methodArity(int methodId)
+    {
+        if (methodId == Id_constructor) return 1;
         return super.methodArity(methodId);
     }
 
-    public Object execMethod
-        (int methodId, IdFunction f,
-         Context cx, Scriptable scope, Scriptable thisObj, Object[] args)
+    public Object execMethod(int methodId, IdFunction f,
+                             Context cx, Scriptable scope,
+                             Scriptable thisObj, Object[] args)
         throws JavaScriptException
     {
-        if (prototypeFlag) {
-            if (methodId == Id_constructor) {
-                return jsConstructor(cx, args, f, thisObj == null);
+        if (methodId == Id_constructor) {
+            if (thisObj != null) {
+                throw Context.reportRuntimeError1("msg.only.from.new", "Call");
             }
+            ScriptRuntime.checkDeprecated(cx, "Call");
+            NativeCall result = new NativeCall();
+            result.setPrototype(getObjectPrototype(scope));
+            return result;
         }
         return super.execMethod(methodId, f, cx, scope, thisObj, args);
     }
 
-    protected String getIdName(int id) {
-        if (prototypeFlag) {
-            if (id == Id_constructor) return "constructor";
-        }
+    protected String getIdName(int id)
+    {
+        if (id == Id_constructor) return "constructor";
         return null;
     }
 
-    protected int mapNameToId(String s) {
-        if (!prototypeFlag) { return 0; }
+    protected int mapNameToId(String s)
+    {
         return s.equals("constructor") ? Id_constructor : 0;
     }
 
     private static final int
         Id_constructor   = 1,
         MAX_PROTOTYPE_ID = 1;
-
-    NativeCall caller;
-    NativeFunction funObj;
-    Scriptable thisObj;
-    private Object[] originalArgs;
-    public int debugPC;
-
-    private boolean prototypeFlag;
 }