jscript: Make global constants non-writable in ES5 mode.

dlls/jscript/global.c

@@ -1087,6 +1087,7 @@ static HRESULT init_constructors(script_ctx_t *ctx, jsdisp_t *object_prototype)
 
 HRESULT init_global(script_ctx_t *ctx)
 {
+    unsigned const_flags = ctx->version >= SCRIPTLANGUAGEVERSION_ES5 ? 0 : PROPF_WRITABLE;
     jsdisp_t *math, *object_prototype, *constr;
     HRESULT hres;
 
@@ -1137,14 +1138,14 @@ HRESULT init_global(script_ctx_t *ctx)
     if(FAILED(hres))
         return hres;
 
-    hres = jsdisp_propput_dontenum(ctx->global, undefinedW, jsval_undefined());
+    hres = jsdisp_define_data_property(ctx->global, undefinedW, const_flags, jsval_undefined());
     if(FAILED(hres))
         return hres;
 
-    hres = jsdisp_propput_dontenum(ctx->global, NaNW, jsval_number(NAN));
+    hres = jsdisp_define_data_property(ctx->global, NaNW, const_flags, jsval_number(NAN));
     if(FAILED(hres))
         return hres;
 
-    hres = jsdisp_propput_dontenum(ctx->global, InfinityW, jsval_number(INFINITY));
+    hres = jsdisp_define_data_property(ctx->global, InfinityW, const_flags, jsval_number(INFINITY));
     return hres;
 }

dlls/mshtml/tests/es5.js

@@ -284,6 +284,23 @@ function test_defineProperty() {
     next_test();
 }
 
+function test_global_properties() {
+    var o;
+
+    /* Make sure that global properties are not writable. */
+    o = NaN;
+    NaN = 1;
+    ok(isNaN(NaN), "NaN = " + NaN);
+    o = undefined;
+    undefined = 1;
+    ok(undefined === o, "NaN = " + NaN);
+    o = Infinity;
+    Infinity = 1;
+    ok(Infinity === o, "Infinity = " + NaN);
+
+    next_test();
+}
+
 var tests = [
     test_date_now,
     test_toISOString,
@@ -291,5 +308,6 @@ var tests = [
     test_isArray,
     test_identifier_keywords,
     test_getOwnPropertyDescriptor,
-    test_defineProperty
+    test_defineProperty,
+    test_global_properties
 ];