Bug 351280

I was trying to register a custom protocol to open a file in kate by clicking a link in konsole, but it wouldn't work with kde-open.

Reproducible: Always

Steps to Reproduce:
1. download open-in-kate.sh, kateopen.xml and kateopen.desktop
2. move open-in-kate.sh into a directory that's in path (e.g. ~/bin), and modify the path in kateopen.desktop 
3. xdg-mime install --novendor kateopen.xml
4. xdg-desktop-menu install --novendor kateopen.desktop
5. xdg-mime default kateopen.desktop x-scheme-handler/kateopen
6. update-mime-database ~/.local/share/mime   
7. update-desktop-database ~/.local/share/applications 
8. kbuildsycoca5 (may or may not be necessary)
9. try kde-open kateopen:///some/file/here:12

Actual Results:  
kioclient(3551)/kio (KRun): #### NO SUPPORT FOR READING! 

Expected Results:  
kate opens with the file

"kioclient cat kateopen:///some/file" returned an error message that made more sense:

kioclient(2820): couldn't create slave: "Unable to create io-slave:
klauncher said: Unknown protocol 'kateopen'.
" 

gnome-open works, kde-open does not.

I opened ~/.local/share/applications/mimeapps.list. The line

x-scheme-handler/kateopen=kateopen.desktop

was missing from "[Added Associations]", it was only present in "[Default Applications]".
Copy-pasting it into "[Added Associations]" fixed the problem. I don't know why it wasn't there, another custom protocol I made a while back (when I was using kde4) was present in both sections.

When trying to reproduce, the most reliable way to get it to detect the change in mimeapps.list (i.e. removing the line from Added Associations causes it to break, adding it back fixes it) is to run

update-mime-database ~/.local/share/mime  
update-desktop-database ~/.local/share/applications 
kbuildsycoca5 (sometimes multiple times)

I'm using Kubuntu 15.04 with the backports ppa, frameworks 5.12.0.