Reading "mimetype" and "categories" entries from a .desktop file that end in a trailing ';' causes an empty string to be added to the mimetype/categories qstringlist. For mimetypes, this causes an invalid mime file to be written as the empty string is used as the lefthand side of the default application entry...
[Default Applications]
=anydesk.desktop;<snip further desktopfiles>
application/clarisworks=libreoffice-calc.desktop;libreoffice-draw.desktop;libreoffice-writer.desktop
...
Reading "mimetype" and "categories" entries from a .desktop file that end in a trailing ';' causes an empty string to be added to the mimetype/categories qstringlist. For mimetypes, this causes an invalid mime file to be written as the empty string is used as the lefthand side of the default application entry...
[Default Applications] =anydesk.desktop;<snip further desktopfiles> application/clarisworks=libreoffice-calc.desktop;libreoffice-draw.desktop;libreoffice-writer.desktop ...