bug#7702: 24.0.50; doc of select-active-regions, cut/paste/kill/yank

[Eli Zaretskii <eliz@gnu.org>]

> From: "Drew Adams" <drew.adams@oracle.com>
> Date: Tue, 21 Dec 2010 20:02:28 -0800
> Cc: 
> 
> Doc string of `select-active-regions':
>  
> "If non-nil, an active region automatically becomes the window
> selection."
>  
> Nowhere in Emacs is it defined or described what a "window selection"
> is.  This new terminology (and perhaps a new concept?) needs to be
> explained to Emacs users.

I fixed that (on the emacs-23 branch) to say

  "If non-nil, an active region automatically sets the primary selection."

> (emacs) `Cut/Paste Other App':
>  
> This node has become _much_ more complicated, and much less clear.
>  
> It is not clear which of the things (all of them? any of them?)
> discussed in this node are for an X window system only.  This needs to
> be clarified.  Distinguish statements that are true for Emacs across
> platforms from statements that are specific to particular platforms - in
> particular but not only, X Window.

I found that I can take care of this by adding the following paragraph
after the first 2 paragraphs:

  @cindex MS-Windows, and primary selection
    MS-Windows provides no primary selection, but Emacs emulates it
  within a single Emacs session: all the features and commands related
  to the primary selection work as described for cutting and pasting
  within the same session, but not across Emacs sessions or with other
  applications.

If I read the whole subsection with this paragraph included, I see no
need for further differentiation between X and MS-Windows.

> For example, the description of `select-active-regions' makes it
> sound like it has no effect on a system, such as MS Windows, that
> has no concept of a primary selection.  If that is so, then say so.

It has the same effect on MS-Windows, with the caveat that the primary
selection "works" only within the current session.

> In general, this content needs cleanup, clarification, and probably some
> reorganization.  The node should cover _Emacs_, not just Emacs on X
> Window.  It should say everything that users need to know about cutting
> and pasting between applications and Emacs.

Please be more specific.  What else is needed, after adding the above
paragraph about MS-Windows specifics?  My reading is that everything
is now described correctly.

> And it (or some other node) should cover pasting between Emacs sessions,
> to the extent that this is not covered under the category of "other
> app".  Does another Emacs session act just like some other, non-Emacs
> app in all respects wrt transferring text?  If not, what are the
> differences?  Does it matter which Emacs versions the Emacs sessions
> manifest?  If so, explain.

AFAIK, there's nothing special about Emacs wrt cutting/pasting between
different applications (with the exception of primary selections on
MS-Windows, which is now covered).  If you know about anything else,
please tell.

> Also, the concepts of "pasting" and "yanking" need to be compared and
> contrasted.  Sometimes Emacs doc seems to treat them as the same;
> sometimes as different.  This just confuses users, especially if there
> is no section that covers the relation between the two explicitly.
> Likewise, cutting and killing.
>  
> Finally, there is a disconnect between the name of node `Cut and Paste'
> and its title, "Killing and Yanking on Graphical Displays".  This mess
> was introduced in Emacs 22.

I fixed that: it now uses "cut and paste", not "kill and yank".