Please add OnlyShowIn=KDE; or similar to kalarm.autostart.desktop (installed to /etc/xdg/autostart/ in Arch Linux). I have multiple desktop environments installed and prefer to keep them separated. If kalarm starts with the desktop (e.g. with gnome) a lot of other KDE apps / daemons are also started. regards -till
kalarm.autostart.desktop is there to ensure that KAlarm starts when the user logs on. If it doesn't start, alarms won't be triggered. This applies whatever desktop is being used. So adding OnlyShowIn=KDE would stop KAlarm working except under the KDE desktop. Note that kalarm won't be started by kalarm.autostart.desktop if it has been configured not to autostart, using KAlarm's settings dialog. If you have special requirements and only want KAlarm to run under KDE, you would need to create a script to set the AutoStart entry in kalarmrc to the appropriate value depending on what desktop was being run, before kalarm.autostart.desktop was invoked at login. I'm marking this bug as invalid, since altering the file as you suggest would prevent KAlarm from working for most users.
In light of further information reported in bug 366562, the bug shouldn't have been marked as invalid. It has now been fixed for KDE Applications 16.08.1. *** This bug has been marked as a duplicate of bug 366562 ***