Comment 28 for bug 2036098

Also: it fails with the kde fallback.

Here's what I did (using the 20230922.1 Lubuntu ISO):

 1. Edited /usr/share/xdg-desktop-portal/lxqt-portals.conf, changing the "default" key to "lxqt;kde;"
 2. Ran `/usr/libexec/xdg-desktop-portal --verbose --replace` in terminal
 3. Ran Firefox in a separate tab in terminal
 4. Pointed Firefox at https://git.lubuntu.me/Lubuntu/artwork/src/branch/ubuntu/mantic/src/usr/share/lubuntu/wallpapers/2310-mantic-minotaur.png and clicked the download button

What happens:

 * no additional windows open
 * no feedback from Firefox, either in terminal or graphically
 * the following from the xdg-desktop-portal tab:
   XDP: document portal returned empty doc id for path '/home/lubuntu/Downloads/2310-mantic-minotaur(4).png'
   XDP: OpenFile: translating path value '/home/lubuntu/Downloads/2310-mantic-minotaur(4).png' to host path '/home/lubuntu/Downloads/2310-mantic-minotaur(4).png'
   XDP: Content type for file /home/lubuntu/Downloads/2310-mantic-minotaur(4).png: image/png
   XDP: Default handler lximage-qt for file, image/png
   XDP: Recommended handlers for file, image/png: display-im6.q16, lximage-qt, firefox_firefox
   XDP: Found in permission store: handler: (null), count: 0 / 3, always ask: 0
   XDP: (null)
   XDP: Opening app chooser