bug#6774: Cut and paste with C-w/mouse-2 not working?

[David De La Harpe Golden]

On 01/08/10 23:04, Angelo Graziosi wrote:
> It seems that with recent trunk sources (also with the last,
> rev.100958), cutting with C-w and then pasting with mouse-2 does not
> work. To reproduce:
>
> 1. emacs -Q &
>
> 2. In the 'scratch' buffer double click on some text, 'buffer', for
> example.
>
> 3. Now cut it: C-w
>
> 4. Go to the bottom of the buffer and paste with mouse-2: empty!
>
> I can paste only with C-y. If at step 3. I use M-w (Copy), then pasting
> with mouse-2 works.

Yes, there's a problem here - I guess emacs is keeping primary bound to 
a span that's become zero-length. Again.

N.B. your case ideally would work in emacs much like in KDE - but emacs 
still has teething problems and sometimes manages to make primary a 
zero-length string.[this is already "fixed" in the horrible selx branch]

> For example, on Kubuntu, one can cut with C-x and the paste with mouse-2
> (Konqueror, Kate,...)

Not exactly - not quite what's really going on. There's a spec for how 
this is supposed to work, and KDE follows it.*

When you have _selected_ the text in KDE before hitting C-x, it is made 
available as the  "primary" x11 selection (referred to as "the 
selection" in klipper*)

C-x makes the text available as the CLIPBOARD x11 selection while 
removing it from the body of the document. (and it's still available on 
PRIMARY too, where emacs fails).

mouse-2 inserts what's in PRIMARY in KDE.

So in KDE, try selecting more/different text, _without_ hitting C-x or 
C-c.  This will change only PRIMARY.

Hitting mouse-2 again will insert the _new_ PRIMARY.

Then hitting C-v will insert the old CLIPBOARD.  To update the clipboard 
you always have to C-x or C-c.

(* though the situation is further complicated by klipper, the KDE 
clipboard daemon, which can be configured to do various strange things 
in this area, I mean KDE's out-of-box defaults).