Bug 510260

SUMMARY
Okular freezes and can not be killed when drive with opened PDF is unmounted. I am not 100% sure it is the unmount operation because the operation was done by PCloud client as mentioned bellow in reproduction steps.

STEPS TO REPRODUCE
1. Install PCloud drive client app from the official site and have it create its folder in your home dir.
2. Place a PDF in that folder, preferably bigger one so Okular can't keep it whole in memory in case it does that.
3. Open that PDF in Okular
4. Exit the PCloud client app (in my case PCloud app was turned off because it notified me that it has an update and I clicked that I want it to update and restart).

It is possible it could also be reproduced by just unmounting the drive the opened PDF is on but I haven't tried that.

OBSERVED RESULT
Okular freezes at this point or after you try to scroll to another end of the document and even kill -9 won't kill it.

EXPECTED RESULT
Okular should notify me that the document is no longer available and turn off.

SOFTWARE/OS VERSIONS
Operating System: Arch Linux 
KDE Plasma Version: 6.4.5
KDE Frameworks Version: 6.18.0
Qt Version: 6.9.2
Kernel Version: 6.16.10-arch1-1 (64-bit)
Graphics Platform: Wayland
Processors: 12 × Intel® Core™ i7-8700K CPU @ 3.70GHz
Memory: 16 GiB of RAM (15.5 GiB usable)
Graphics Processor: NVIDIA GeForce GTX 1080 Ti

ADDITIONAL INFORMATION