Bug 484824

SUMMARY
Having a file in a fuse mount point (in my case: mergerfs, an union filesystem) confuses dolphin in the detection of that file type and can't open it by simply pressing "enter"

for example on existing setup:

Changing to the mergerfs pool folder, then create a file in terminal like "echo asdf>xyz".
Go with dolphin to that folder.
Pressing "enter" in dolphin to open xyz gives unknown file type (application/octet-stream)
Right-click, open with, gives simple text file (text/plain)
So there seems to be a confusion in detection.
Choosing "remember association" on the "open with", does not work in the sense that next time pressing enter to open xyz gives the same problem.

"xdg-mime query filetype xyz" does list the type as text/plain.
"xdg-open xyz" opens file even if there's a error : "kf.service.services: KApplicationTrader: mimeType "x-scheme-handler/file" not found". This error might be another unrelated bug.
All files, regardless if they work or not in dolphin, give the above error but open anyway with xdg-open.
The "file" tool returns "xyz: ASCII text", so it also detects it correctly.

To replicate outside of existing setup, I did the following:
-create virtual machine with 2 drives

-install o.s. then mergerfs (it was version 2.33.3.  Tried 2.40.2 in real machine, it doesn't change a thing)

-created the folder for the mount point of the mergerfs pool (for ex: /media/user/mergerfspool)

-created the folder for the mount point of second drive (for ex: /media/user/drive2)

-change ownership of those mount points to me (user)

-change /etc/fstab to represent all mounts and mergerfs.
----for Mergerfs it can be (without quotes) "/user:/media/user/drive2 /media/user/mergerfspool fuse.mergerfs defaults,func.create=rand,moveonenospc=true,allow_other,use_ino,fsname=mergerFS 0 0"

-create the file: " echo asdf>/media/user/mergerfspool/xyz "

result with dolphin:
-if xyz is opened directly from the branch (real underling folder) or is outside mergerfs pool, it always works.
-if xyz is opened from the mergerfs pool, it will not open and instead give the above behavior.


As a side notes:
-file manager "Krusader" has no problem either way.
-I also tested with another fuse mount, with sshfs. Same problem.
-started happening when upgraded to plasma version 6.0.3 and all that came with it like "KDE Gear 24.02.1"


Operating System: KDE neon 6.0
KDE Plasma Version: 6.0.3
KDE Frameworks Version: 6.0.0
Qt Version: 6.6.2
Kernel Version: 6.5.0-26-generic (64-bit)
Graphics Platform: X11
System Version: -CF