fix random freezing on select/create empty textitems #736

        block = doc.firstBlock()

        if block.isValid():

            it = block.begin()

            # causes frozen for pyside==6.8.1

            if it.atEnd():

                firstFontSize = block.charFormat().fontPointSize()

            else:

                # empty blocks causes frozen for pyside==6.8.1

                # also randomly freezes pyqt==6.6.1 https://github.com/dmMaze/BallonsTranslator/issues/736

                firstFontSize = it.fragment().charFormat().fontPointSize()

        else:

            return False