jscript: Fixed deleting nonexisting properties from member expression.

dlls/jscript/dispex.c

@@ -1516,10 +1516,12 @@ HRESULT disp_delete_name(script_ctx_t *ctx, IDispatch *disp, jsstr_t *name, BOOL
         dispex_prop_t *prop;
 
         hres = find_prop_name(jsdisp, string_hash(name->str), name->str, &prop);
-        if(prop)
+        if(prop) {
             hres = delete_prop(prop, ret);
-        else
-            hres = DISP_E_MEMBERNOTFOUND;
+        }else {
+            *ret = TRUE;
+            hres = S_OK;
+        }
 
         jsdisp_release(jsdisp);
         return hres;

dlls/jscript/tests/lang.js

@@ -1121,6 +1121,8 @@ ok(typeof(tmp.test) === "undefined", "tmp.test type = " + typeof(tmp.test));
 ok(!("test" in tmp), "test is still in tmp after delete?");
 for(iter in tmp)
     ok(false, "tmp has prop " + iter);
+ok((delete tmp.test) === true, "deleting test didn't return true");
+ok((delete tmp.nonexistent) === true, "deleting nonexistent didn't return true");
 
 tmp = new Object();
 tmp.test = false;