Don't Sync() if there is no buffer. This allows derived classes that handle the buffer differently (e.g. reuse the buffer).


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76388 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775