Created attachment 126707 [details]
Affected DJVU file

SUMMARY

I have a NAS connected to my PC with Samba protocol (mounted by mount.cifs in /etc/fstab, not Dolphin). Some (but not all) DJVU files on it can not be opened in Okular. When I find such a file in Dolphin and doubleclick it, Okular window appears and just stays empty (as in: displays what is underneath it) for infinite time. It does not generate high CPU load. 

However, the same file can be opened without problems in these cases:
1) If a NAS is connected with NFS or SSHFS. 
2) If a file was copied from the share to a local folder and opened from there. 

Not all DJVU files are affected, but those that are affected are affected every time. 

if started from CLI, okular prints "# of pages:173" and nothing else. 


STEPS TO REPRODUCE
1. Put an affected file on a Samba share
2. Mount the share on Linux machine
3. Try to open in Okular. 



SOFTWARE/OS VERSIONS
Operating System: Arch Linux 
KDE Plasma Version: 5.18.2
KDE Frameworks Version: 5.67.0
Qt Version: 5.14.1
Kernel Version: 5.5.8-zen1-1-zen
OS Type: 64-bit
Processors: 8 × Intel® Core™ i7-3770 CPU @ 3.40GHz
Memory: 15.6 GiB of RAM


ADDITIONAL INFORMATION
An example of an affected file is in attachment.