oleaut32: Accept DISP_E_PARAMNOTFOUND for missing optional parameters in…

dlls/oleaut32/tests/tmarshal.c

@@ -2861,7 +2861,7 @@ static void test_typelibmarshal(void)
     ok(!lstrcmpW(bstr, szCat), "IWidget_get_Name should have returned string \"Cat\" instead of %s\n", wine_dbgstr_w(bstr));
     SysFreeString(bstr);
 
-    /* call DoSomething */
+    /* call DoSomething without optional arguments */
     VariantInit(&vararg[0]);
     VariantInit(&vararg[1]);
     V_VT(&vararg[1]) = VT_R8;
@@ -2876,6 +2876,43 @@ static void test_typelibmarshal(void)
     ok(V_VT(&varresult) == VT_EMPTY, "varresult should be VT_EMPTY\n");
     VariantClear(&varresult);
 
+    /* call DoSomething with optional argument set to VT_EMPTY */
+    VariantInit(&vararg[0]);
+    VariantInit(&vararg[1]);
+    VariantInit(&vararg[2]);
+    V_VT(&vararg[2]) = VT_R8;
+    V_R8(&vararg[2]) = 3.141;
+    dispparams.cNamedArgs = 0;
+    dispparams.cArgs = 3;
+    dispparams.rgdispidNamedArgs = NULL;
+    dispparams.rgvarg = vararg;
+    VariantInit(&varresult);
+    hr = IDispatch_Invoke(pDispatch, DISPID_TM_DOSOMETHING, &IID_NULL, LOCALE_NEUTRAL, DISPATCH_METHOD, &dispparams, &varresult, &excepinfo, NULL);
+    ok_ole_success(hr, IDispatch_Invoke);
+    ok(V_VT(&varresult) == VT_EMPTY, "varresult should be VT_EMPTY\n");
+    VariantClear(&varresult);
+
+    /* call DoSomething with optional arguments set to VT_ERROR/DISP_E_PARAMNOTFOUND */
+    VariantInit(&vararg[0]);
+    VariantInit(&vararg[1]);
+    VariantInit(&vararg[2]);
+    VariantInit(&vararg[3]);
+    V_VT(&vararg[3]) = VT_R8;
+    V_R8(&vararg[3]) = 3.141;
+    V_VT(&vararg[1]) = VT_ERROR;
+    V_ERROR(&vararg[1]) = DISP_E_PARAMNOTFOUND;
+    V_VT(&vararg[0]) = VT_ERROR;
+    V_ERROR(&vararg[0]) = DISP_E_PARAMNOTFOUND;
+    dispparams.cNamedArgs = 0;
+    dispparams.cArgs = 4;
+    dispparams.rgdispidNamedArgs = NULL;
+    dispparams.rgvarg = vararg;
+    VariantInit(&varresult);
+    hr = IDispatch_Invoke(pDispatch, DISPID_TM_DOSOMETHING, &IID_NULL, LOCALE_NEUTRAL, DISPATCH_METHOD, &dispparams, &varresult, &excepinfo, NULL);
+    ok_ole_success(hr, IDispatch_Invoke);
+    ok(V_VT(&varresult) == VT_EMPTY, "varresult should be VT_EMPTY\n");
+    VariantClear(&varresult);
+
     /* call get_State */
     dispparams.cNamedArgs = 0;
     dispparams.cArgs = 0;

dlls/oleaut32/typelib.c

@@ -7217,7 +7217,8 @@ static HRESULT WINAPI ITypeInfo_fnInvoke(
                         break;
                     }
                 }
-                else if (src_arg)
+                else if (src_arg && !((wParamFlags & PARAMFLAG_FOPT) &&
+                         V_VT(src_arg) == VT_ERROR && V_ERROR(src_arg) == DISP_E_PARAMNOTFOUND))
                 {
                     TRACE("%s\n", debugstr_variant(src_arg));