assertion failure while reading markdown file that contains front matter but is otherwise empty

4   qAbort                        qglobal.cpp                161 
5   qt_message_fatal<QString&>    qlogging.cpp               2060
6   qt_message                    qlogging.cpp               374 
7   QMessageLogger::fatal         qlogging.cpp               897 
8   qt_assert                     qassert.cpp                68  
9   QByteArray::verify            qbytearray.h               579 
10  QByteArray::at                qbytearray.h               613 
11  QTextMarkdownImporter::import qtextmarkdownimporter.cpp  151 
12  QTextDocument::setMarkdown    qtextdocument.cpp          3607