Gabriel Ivăncescu : jscript: Implement Function.prototype.bind's `thisArg` properly.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 35a65559293e6ef57f0423ab488d489939074204
URL:    https://gitlab.winehq.org/wine/wine/-/commit/35a65559293e6ef57f0423ab488d489...

Author: Gabriel Ivăncescu <gabrielopcode(a)gmail.com>
Date:   Fri Oct 14 22:14:43 2022 +0300

jscript: Implement Function.prototype.bind's `thisArg` properly.

Signed-off-by: Gabriel Ivăncescu <gabrielopcode(a)gmail.com>

---

 dlls/jscript/function.c  | 40 +++++++++++++++++++++-------------------
 dlls/mshtml/tests/es5.js | 17 +++++++++++++++++
 2 files changed, 38 insertions(+), 19 deletions(-)

diff --git a/dlls/jscript/function.c b/dlls/jscript/function.c
index bf152e22868..8009f3a5d8b 100644
--- a/dlls/jscript/function.c
+++ b/dlls/jscript/function.c
@@ -57,7 +57,7 @@ typedef struct {
 typedef struct {
     FunctionInstance function;
     FunctionInstance *target;
-    IDispatch *this;
+    jsval_t this;
     unsigned argc;
     jsval_t args[1];
 } BindFunction;
@@ -70,7 +70,7 @@ typedef struct {
     unsigned argc;
 } ArgumentsInstance;
 
-static HRESULT create_bind_function(script_ctx_t*,FunctionInstance*,IDispatch*,unsigned,jsval_t*,jsdisp_t**r);
+static HRESULT create_bind_function(script_ctx_t*,FunctionInstance*,jsval_t,unsigned,jsval_t*,jsdisp_t**r);
 
 static inline FunctionInstance *function_from_jsdisp(jsdisp_t *jsdisp)
 {
@@ -448,7 +448,7 @@ static HRESULT Function_call(script_ctx_t *ctx, jsval_t vthis, WORD flags, unsig
 static HRESULT Function_bind(script_ctx_t *ctx, jsval_t vthis, WORD flags, unsigned argc, jsval_t *argv,
         jsval_t *r)
 {
-    IDispatch *bound_this = NULL;
+    jsval_t bound_this = jsval_undefined();
     FunctionInstance *function;
     jsdisp_t *new_function;
     HRESULT hres;
@@ -459,18 +459,19 @@ static HRESULT Function_bind(script_ctx_t *ctx, jsval_t vthis, WORD flags, unsig
         return JS_E_FUNCTION_EXPECTED;
 
     if(argc < 1) {
-        FIXME("no this argument\n");
-        return E_NOTIMPL;
-    }
-
-    if(is_object_instance(argv[0])) {
-        bound_this = get_object(argv[0]);
-    }else if(!is_null(argv[0])) {
-        FIXME("%s is not an object instance\n", debugstr_jsval(argv[0]));
-        return E_NOTIMPL;
+        argc = 1;
+    }else if(is_null(argv[0])) {
+        bound_this = argv[0];
+    }else if(!is_undefined(argv[0])) {
+        IDispatch *obj;
+        hres = to_object(ctx, argv[0], &obj);
+        if(FAILED(hres))
+            return hres;
+        bound_this = jsval_disp(obj);
     }
 
     hres = create_bind_function(ctx, function, bound_this, argc - 1, argv + 1, &new_function);
+    jsval_release(bound_this);
     if(FAILED(hres))
         return hres;
 
@@ -849,8 +850,7 @@ static HRESULT BindFunction_call(script_ctx_t *ctx, FunctionInstance *func, jsva
             memcpy(call_args + function->argc, argv, argc * sizeof(*call_args));
     }
 
-    hres = function->target->vtbl->call(ctx, function->target, function->this ? jsval_disp(function->this) : jsval_null(),
-                                        flags, call_argc, call_args, r);
+    hres = function->target->vtbl->call(ctx, function->target, function->this, flags, call_argc, call_args, r);
 
     heap_free(call_args);
     return hres;
@@ -877,8 +877,7 @@ static void BindFunction_destructor(FunctionInstance *func)
     for(i = 0; i < function->argc; i++)
         jsval_release(function->args[i]);
     jsdisp_release(&function->target->dispex);
-    if(function->this)
-        IDispatch_Release(function->this);
+    jsval_release(function->this);
 }
 
 static const function_vtbl_t BindFunctionVtbl = {
@@ -888,7 +887,7 @@ static const function_vtbl_t BindFunctionVtbl = {
     BindFunction_destructor
 };
 
-static HRESULT create_bind_function(script_ctx_t *ctx, FunctionInstance *target, IDispatch *bound_this, unsigned argc,
+static HRESULT create_bind_function(script_ctx_t *ctx, FunctionInstance *target, jsval_t bound_this, unsigned argc,
                                     jsval_t *argv, jsdisp_t **ret)
 {
     BindFunction *function;
@@ -902,8 +901,11 @@ static HRESULT create_bind_function(script_ctx_t *ctx, FunctionInstance *target,
     jsdisp_addref(&target->dispex);
     function->target = target;
 
-    if(bound_this)
-        IDispatch_AddRef(function->this = bound_this);
+    hres = jsval_copy(bound_this, &function->this);
+    if(FAILED(hres)) {
+        jsdisp_release(&function->function.dispex);
+        return hres;
+    }
 
     for(function->argc = 0; function->argc < argc; function->argc++) {
         hres = jsval_copy(argv[function->argc], function->args + function->argc);
diff --git a/dlls/mshtml/tests/es5.js b/dlls/mshtml/tests/es5.js
index bfaacd1bd5b..e22f610e197 100644
--- a/dlls/mshtml/tests/es5.js
+++ b/dlls/mshtml/tests/es5.js
@@ -1188,6 +1188,23 @@ sync_test("bind", function() {
     ok(t != a, "t == a");
 
     ok(Function.prototype.bind.length === 1, "Function.prototype.bind.length = " + Function.prototype.bind.length);
+
+    ((function() { ok(this === window, "bind() this = " + this); }).bind())();
+    ((function() { ok(this === window, "bind(undefined) = " + this); }).bind(undefined))();
+    ((function() { ok(this === window, "bind(nullDisp) = " + this); }).bind(external.nullDisp))();
+    ((function() {
+        ok(typeof(this) === "object", "bind(42) typeof(this) = " + typeof(this));
+        ok(this.valueOf() === 42, "bind(42) this = " + this);
+    }).bind(42))();
+
+    r = (Object.prototype.toString.bind())();
+    ok(r === "[object Undefined]", "toString.bind() returned " + r);
+    r = (Object.prototype.toString.bind(undefined))();
+    ok(r === "[object Undefined]", "toString.bind(undefined) returned " + r);
+    r = (Object.prototype.toString.bind(null))();
+    ok(r === "[object Null]", "toString.bind(null) returned " + r);
+    r = (Object.prototype.toString.bind(external.nullDisp))();
+    ok(r === "[object Null]", "toString.bind(nullDisp) returned " + r);
 });
 
 sync_test("keys", function() {