jscript: Delay arguments object until it's accessed and properly detach it after function exits.

dlls/jscript/engine.c

@@ -558,6 +558,12 @@ static HRESULT detach_variable_object(script_ctx_t *ctx, call_frame_t *frame)
     assert(frame == frame->base_scope->frame);
     assert(frame->variable_obj == frame->base_scope->jsobj);
 
+    if(!frame->arguments_obj) {
+        hres = setup_arguments_object(ctx, frame);
+        if(FAILED(hres))
+            return hres;
+    }
+
     frame->base_scope->frame = NULL;
 
     for(i = 0; i < frame->function->param_cnt; i++) {
@@ -609,12 +615,19 @@ static HRESULT identifier_eval(script_ctx_t *ctx, BSTR identifier, exprval_t *re
             if(scope->frame) {
                 function_code_t *func = scope->frame->function;
                 local_ref_t *ref = bsearch(identifier, func->locals, func->locals_cnt, sizeof(*func->locals), local_ref_cmp);
+                static const WCHAR argumentsW[] = {'a','r','g','u','m','e','n','t','s',0};
 
                 if(ref) {
                     ret->type = EXPRVAL_STACK_REF;
                     ret->u.off = scope->frame->arguments_off - ref->ref - 1;
                     return S_OK;
                 }
+
+                if(!strcmpW(identifier, argumentsW)) {
+                    hres = detach_variable_object(ctx, scope->frame);
+                    if(FAILED(hres))
+                        return hres;
+                }
             }
             if(scope->jsobj)
                 hres = jsdisp_get_id(scope->jsobj, identifier, fdexNameImplicit, &id);
@@ -2701,7 +2714,7 @@ static HRESULT bind_event_target(script_ctx_t *ctx, function_code_t *func, jsdis
     return hres;
 }
 
-static HRESULT setup_scope(script_ctx_t *ctx, call_frame_t *frame, unsigned argc, jsval_t *argv, jsdisp_t *function_instance)
+static HRESULT setup_scope(script_ctx_t *ctx, call_frame_t *frame, unsigned argc, jsval_t *argv)
 {
     const unsigned orig_stack = ctx->stack_top;
     unsigned i;
@@ -2736,7 +2749,7 @@ static HRESULT setup_scope(script_ctx_t *ctx, call_frame_t *frame, unsigned argc
 
     frame->pop_locals = ctx->stack_top - orig_stack;
     frame->base_scope->frame = frame;
-    return setup_arguments_object(ctx, frame, argc, function_instance);
+    return S_OK;
 }
 
 HRESULT exec_source(script_ctx_t *ctx, DWORD flags, bytecode_t *bytecode, function_code_t *function, scope_chain_t *scope,
@@ -2799,12 +2812,13 @@ HRESULT exec_source(script_ctx_t *ctx, DWORD flags, bytecode_t *bytecode, functi
 
     frame->function = function;
     frame->ret = jsval_undefined();
+    frame->argc = argc;
 
     if(scope) {
         frame->base_scope = frame->scope = scope_addref(scope);
 
         if(!(flags & (EXEC_GLOBAL|EXEC_EVAL))) {
-            hres = setup_scope(ctx, frame, argc, argv, function_instance);
+            hres = setup_scope(ctx, frame, argc, argv);
             if(FAILED(hres)) {
                 heap_free(frame);
                 return hres;

dlls/jscript/engine.h

@@ -217,6 +217,7 @@ typedef struct _call_frame_t {
     jsdisp_t *arguments_obj;
     DWORD flags;
 
+    unsigned argc;
     unsigned pop_locals;
     unsigned arguments_off;
 
@@ -235,5 +236,5 @@ HRESULT exec_source(script_ctx_t*,DWORD,bytecode_t*,function_code_t*,scope_chain
         jsdisp_t*,jsdisp_t*,unsigned,jsval_t*,jsval_t*) DECLSPEC_HIDDEN;
 
 HRESULT create_source_function(script_ctx_t*,bytecode_t*,function_code_t*,scope_chain_t*,jsdisp_t**) DECLSPEC_HIDDEN;
-HRESULT setup_arguments_object(script_ctx_t*,call_frame_t*,unsigned,jsdisp_t*) DECLSPEC_HIDDEN;
+HRESULT setup_arguments_object(script_ctx_t*,call_frame_t*) DECLSPEC_HIDDEN;
 void detach_arguments_object(jsdisp_t*) DECLSPEC_HIDDEN;

dlls/jscript/function.c

@@ -159,7 +159,7 @@ static const builtin_info_t Arguments_info = {
     Arguments_idx_put
 };
 
-HRESULT setup_arguments_object(script_ctx_t *ctx, call_frame_t *frame, unsigned argc, jsdisp_t *function_instance)
+HRESULT setup_arguments_object(script_ctx_t *ctx, call_frame_t *frame)
 {
     ArgumentsInstance *args;
     HRESULT hres;
@@ -176,11 +176,11 @@ HRESULT setup_arguments_object(script_ctx_t *ctx, call_frame_t *frame, unsigned
         return hres;
     }
 
-    args->function = function_from_jsdisp(jsdisp_addref(function_instance));
-    args->argc = argc;
+    args->function = function_from_jsdisp(jsdisp_addref(frame->function_instance));
+    args->argc = frame->argc;
     args->frame = frame;
 
-    hres = jsdisp_propput_dontenum(&args->jsdisp, lengthW, jsval_number(argc));
+    hres = jsdisp_propput_dontenum(&args->jsdisp, lengthW, jsval_number(args->argc));
     if(SUCCEEDED(hres))
         hres = jsdisp_propput_dontenum(&args->jsdisp, caleeW, jsval_disp(to_disp(&args->function->dispex)));
     if(SUCCEEDED(hres))
@@ -561,11 +561,17 @@ static HRESULT Function_get_arguments(script_ctx_t *ctx, jsdisp_t *jsthis, jsval
 {
     FunctionInstance *function = function_from_jsdisp(jsthis);
     call_frame_t *frame;
+    HRESULT hres;
 
     TRACE("\n");
 
     for(frame = ctx->call_ctx; frame; frame = frame->prev_frame) {
         if(frame->function_instance == &function->dispex) {
+            if(!frame->arguments_obj) {
+                hres = setup_arguments_object(ctx, frame);
+                if(FAILED(hres))
+                    return hres;
+            }
             *r = jsval_obj(jsdisp_addref(frame->arguments_obj));
             return S_OK;
         }