Bug 537863 - Make various global properties (NaN, Infinity, undefined) readonly per ES5. r=jorendorff

js/src/jsapi.cpp

@@ -1343,7 +1343,8 @@ JS_InitStandardClasses(JSContext *cx, JSObject *obj)
     /* Define a top-level property 'undefined' with the undefined value. */
     atom = cx->runtime->atomState.typeAtoms[JSTYPE_VOID];
     if (!obj->defineProperty(cx, ATOM_TO_JSID(atom), JSVAL_VOID,
-                             JS_PropertyStub, JS_PropertyStub, JSPROP_PERMANENT)) {
+                             JS_PropertyStub, JS_PropertyStub,
+                             JSPROP_PERMANENT | JSPROP_READONLY)) {
         return JS_FALSE;
     }
 
@@ -1550,7 +1551,7 @@ JS_ResolveStandardClass(JSContext *cx, JSObject *obj, jsval id,
         *resolved = JS_TRUE;
         return obj->defineProperty(cx, ATOM_TO_JSID(atom), JSVAL_VOID,
                                    JS_PropertyStub, JS_PropertyStub,
-                                   JSPROP_PERMANENT);
+                                   JSPROP_PERMANENT | JSPROP_READONLY);
     }
 
     /* Try for class constructors/prototypes named by well-known atoms. */

js/src/jsnum.cpp

@@ -790,14 +790,15 @@ js_InitNumberClass(JSContext *cx, JSObject *obj)
 
     /* ECMA 15.1.1.1 */
     rt = cx->runtime;
-    if (!JS_DefineProperty(cx, obj, js_NaN_str, rt->NaNValue,
-                           NULL, NULL, JSPROP_PERMANENT)) {
+    if (!JS_DefineProperty(cx, obj, js_NaN_str, rt->NaNValue, JS_PropertyStub, JS_PropertyStub,
+                           JSPROP_PERMANENT | JSPROP_READONLY)) {
         return NULL;
     }
 
     /* ECMA 15.1.1.2 */
     if (!JS_DefineProperty(cx, obj, js_Infinity_str, rt->positiveInfinityValue,
-                           NULL, NULL, JSPROP_PERMANENT)) {
+                           JS_PropertyStub, JS_PropertyStub,
+                           JSPROP_PERMANENT | JSPROP_READONLY)) {
         return NULL;
     }
     return proto;

js/src/tests/ecma_5/misc/browser.js

@@ -0,0 +1 @@
+

js/src/tests/ecma_5/misc/global-numeric-properties.js

@@ -0,0 +1,60 @@
+/*
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/licenses/publicdomain/
+ */
+
+var gTestfile = 'global-numeric-properties.js';
+//-----------------------------------------------------------------------------
+var BUGNUMBER = 537863;
+var summary =
+  'undefined, Infinity, and NaN global properties should not be writable';
+
+print(BUGNUMBER + ": " + summary);
+
+/**************
+ * BEGIN TEST *
+ **************/
+
+var desc, old, error;
+var global = this;
+
+var names = ["NaN", "Infinity", "undefined"];
+
+for (var i = 0; i < names.length; i++)
+{
+  var name = names[i];
+  desc = Object.getOwnPropertyDescriptor(global, name);
+  assertEq(desc !== undefined, true, name + " should be present");
+  assertEq(desc.enumerable, false, name + " should not be enumerable");
+  assertEq(desc.configurable, false, name + " should not be configurable");
+  assertEq(desc.writable, false, name + " should not be writable");
+
+  old = global[name];
+  global[name] = 17;
+  assertEq(global[name], old, name + " changed on setting?");
+
+  error = "before";
+  try
+  {
+    throw new TypeError("SpiderMonkey doesn't currently implement " +
+                        "strict-mode throwing when setting a readonly " +
+                        "property, not running this bit of test for now; " +
+                        "see bug 537873");
+
+    (function() { "use strict"; global[name] = 42; error = "didn't throw"; })();
+  }
+  catch (e)
+  {
+    if (e instanceof TypeError)
+      error = "typeerror";
+    else
+      error = "bad exception: " + e;
+  }
+  assertEq(error, "typeerror", "wrong strict mode error setting " + name);
+}
+
+/******************************************************************************/
+
+reportCompare(true, true);
+
+print("All tests passed!");

js/src/tests/ecma_5/misc/jstests.list

@@ -0,0 +1,2 @@
+url-prefix ../../jsreftest.html?test=ecma_5/misc/
+script global-numeric-properties.js

js/src/tests/ecma_5/misc/shell.js

@@ -0,0 +1 @@
+gTestsubsuite = 'misc';