[PATCH v2 2/2] jscript: Pass undefined 'this' instead of null in ES5 mode.

[Gabriel Ivăncescu]

Based on the spec (ECMA-262 5.1 Edition 11.2.3.7), whereas the ES3 spec
says it gets replaced with null.

Signed-off-by: Gabriel Ivăncescu <gabrielopcode at gmail.com>
---
 dlls/jscript/function.c  | 7 ++++++-
 dlls/mshtml/tests/es5.js | 3 +++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/dlls/jscript/function.c b/dlls/jscript/function.c
index 942ec9d..a18705b 100644
--- a/dlls/jscript/function.c
+++ b/dlls/jscript/function.c
@@ -268,13 +268,18 @@ static inline HRESULT call(script_ctx_t *ctx, FunctionInstance *function, jsval_
 HRESULT Function_invoke(jsdisp_t *func_this, IDispatch *jsthis, WORD flags, unsigned argc, jsval_t *argv, jsval_t *r)
 {
     FunctionInstance *function;
+    jsval_t vthis;
 
     TRACE("func %p this %p\n", func_this, jsthis);
 
     assert(is_class(func_this, JSCLASS_FUNCTION));
     function = function_from_jsdisp(func_this);
 
-    return call(function->dispex.ctx, function, jsthis ? jsval_disp(jsthis) : jsval_null(), flags, argc, argv, r);
+    if(jsthis)
+        vthis = jsval_disp(jsthis);
+    else
+        vthis = function->dispex.ctx->version < SCRIPTLANGUAGEVERSION_ES5 ? jsval_null() : jsval_undefined();
+    return call(function->dispex.ctx, function, vthis, flags, argc, argv, r);
 }
 
 static HRESULT Function_get_length(script_ctx_t *ctx, jsdisp_t *jsthis, jsval_t *r)
diff --git a/dlls/mshtml/tests/es5.js b/dlls/mshtml/tests/es5.js
index fb756ac..b02f71c 100644
--- a/dlls/mshtml/tests/es5.js
+++ b/dlls/mshtml/tests/es5.js
@@ -1795,6 +1795,9 @@ sync_test("builtins detached scope this", function() {
     var r = ((function() { var f = Object.prototype.toString; return (function() { return f(); }); })())();
     ok(r === "[object Undefined]", "Object.toString returned " + r);
 
+    var r = (function() { var f = Object.prototype.toString; return f(); })();
+    ok(r === "[object Undefined]", "Object.toString returned " + r);
+
     var r = ((function() { return (function() { return this; }); })())();
     ok(r === window, "detached scope this = " + r);
 });
-- 
2.34.1