fix ordering of function parameters, closes #15985

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75897 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
avoid potential NULL pointer dereference, closes #15993

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75898 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775