user32: Call UpdateWindow() during DIALOG_CreateIndirect.

dlls/user32/dialog.c

@@ -703,6 +703,7 @@ static HWND DIALOG_CreateIndirect( HINSTANCE hInst, LPCVOID dlgTemplate,
         if (template.style & WS_VISIBLE && !(GetWindowLongW( hwnd, GWL_STYLE ) & WS_VISIBLE))
         {
            NtUserShowWindow( hwnd, SW_SHOWNORMAL );   /* SW_SHOW doesn't always work */
+            UpdateWindow( hwnd );
         }
         return hwnd;
     }