Bug 452109

SUMMARY

Dolphin doesn't show thumbnails on FUSE filesystems.

STEPS TO REPRODUCE
1. dd if=/dev/zero of=test bs=1M count=1K
2. mkfs.ntfs -F test
3. mkdir /media/tmp; mount.ntfs-3g test /media/tmp
4. mkdir /media/tmp/test; cp <some-picture-file> /media/tmp/test/; chmod -R 777 /media/tmp
5. Navigate to the /media/tmp folder in Dolphin and turn on previews.

OBSERVED RESULT

You will see that the test-folder doesn't show the thumbnail of the file in it.
It works on all other filesystems, but not on filesystems mounted via FUSE.

EXPECTED RESULT

The folder should show the thumbnail of the file in it.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: tested on Fedora 35 and Ubuntu 21.10 (with 22.04 repo in apt)
Dolphin: 21.08.1 works correctly, 21.12.2 has the issue