Created attachment 837287 [details]
Powerpoint file which libreoffice cannot handle

My daughter's school is distributing powerpoint files to support home learning,
and some of these have a very bad effect on libreoffice. When you open the file
and start paging through it the soffice.bin process consumes CPU and memory
uncontrollably, and the whole X session soon becomes unusable.

The same thing happens if you try to export to PDF, or use unoconv to do a
batch conversion.

Libreoffice is version LibreOffice 6.4.2.2 40(Build:2).

To reproduce, type
unoconv -f pdf -T 20 EVIL-working-in-the-textile-mills.pptx

It is a good idea to set up a terminal session (using cntrl-alt-F1) before you
start the conversion so that you can see what is going on and kill the rogue
process.