I don't if it is related, but a part of this bug is not solved. (confirming to marked as duplicate bug #144722.
I can indeed now start X-applications with root.
I still can't start applications as another user on my local system (user "test" in the below example) without doing "xhost +local:" (xauth does not work either) first. With the previous kdesu I didn't need to set "xhost +local:". Another change is that I don't need to fill in the password of user "test", but my own password that I also use when I want to start a root-application with sudo/kdesudo. So I can now access every user on my system with my own password. That is off course very handy, but confusing.
I don't if it is related, but a part of this bug is not solved. (confirming to marked as duplicate bug #144722.
I can indeed now start X-applications with root.
I still can't start applications as another user on my local system (user "test" in the below example) without doing "xhost +local:" (xauth does not work either) first. With the previous kdesu I didn't need to set "xhost +local:". Another change is that I don't need to fill in the password of user "test", but my own password that I also use when I want to start a root-application with sudo/kdesudo. So I can now access every user on my system with my own password. That is off course very handy, but confusing.