libreoffice/htmlfuzzer: Bad-cast to SfxPoolItem from invalid vptr in SwAttrHandler::FontChg

Project: git://anongit.freedesktop.org/libreoffice/core Detailed report: https://oss-fuzz.com/testcase?key=5259221261090816 Project: libreoffice Fuzzer: libFuzzerlibreofficehtmlfuzzer Fuzz target binary: htmlfuzzer Job Type: libfuzzerubsanlibreoffice Platform Id: linux Crash Type: Bad-cast Crash...