Incorrect use of PRIMARY and CLIPBOARD clipboards

[Andreas Rönnquist]

Sakura doesn't seem to separate PRIMARY and CLIPBOARD clipboards properly -

* What exactly did you do (or not do) that was effective (or ineffective)?
- launch a sakura terminal;
- type 'ls /';
- select the word 'bin';
- press the right mouse button and select 'copy' from the dropdown menu (copy to CLIPBOARD);
- select the word 'home' (copy to PRIMARY);

- now press the right mouse button and select 'paste' (paste from CLIPBOARD);
- now press the middle mouse button (paste from PRIMARY);

* What was the outcome of this action?
- on the prompt I get 'homehome';

* What outcome did you expect instead?
- on the prompt I should get 'binhome';

This is originally reported in the Debian bugtracking system:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=997023

and I can reproduce the behaviour above.