bug#7196: 24.0.50; NEWS item "Selection changes"

[Eli Zaretskii <eliz@gnu.org>]

> From: "Drew Adams" <drew.adams@oracle.com>
> Date: Tue, 12 Oct 2010 07:56:40 -0700
> Cc: 
> 
> The NEWS item is woefully incomplete.  It doesn't explain much of
> anything about the selection changes for Emacs 24 - and they are
> radical changes.
>  
> Among other things, NEWS should detail the differences from the
> previous behavior, and explain clearly how to return to the
> previous behavior (exactly, completely).

The new text is reproduced below.  If it is good enough, this bug
report can be closed.

  ** Selection changes.

  The default handling of clipboard and primary selections has been
  changed to conform with other X applications.

  The new behavior is that by default Emacs does not put text into the
  clipboard, and does not add it to kill-ring, merely because the text
  was selected.  Only commands that kill text or copy it to the
  kill-ring (C-w, M-w, C-k, etc.) put the killed text into the
  clipboard.  Selected text is put into the primary selection (on
  systems, such as X, that support the primary selection separately from
  the clipboard).

  Similarly, Emacs by default does not retrieve text from the clipboard
  when the mouse (e.g., mouse-2) is used for pasting text selected in
  another application.  Text from the clipboard is retrieved only by
  C-y, M-y and other commands that yank text from the kill-ring.  Mouse
  commands that paste text retrieve text from the primary selection, on
  systems that support it separately from the clipboard.

  In other words, the default behavior is that mouse gestures that
  select and paste text work with the primary selection, while keyboard
  commands that kill/copy and paste text work with the clipboard.

  This change also means that the "Copy", "Cut", and "Paste" items of
  the menu-bar "Edit" menu are now exactly equivalent to, respectively
  M-w, C-w, and C-y.

  To get back the previous behavior, whereby mouse gestures set the
  clipboard and retrieve text from there, customize the variables
  `mouse-drag-copy-region' and (on X only) `x-select-enable-primary'.
  If you don't want Emacs to put the text into the clipboard, only to
  the primary selection, additionally customize
  `x-select-enable-clipboard' to nil.

  These changes in the default behavior are reflected in the default
  values of several variables:

  *** `select-active-regions' now defaults to t, so active regions set
  the primary selection.  It was nil in previous versions.

  It also accepts a new value, `only', which means to only set the
  primary selection for temporarily active regions (usually made by
  mouse-dragging or shift-selection).

  *** `mouse-2' is now bound to `mouse-yank-primary'.
  Previously, it was bound to `mouse-yank-at-click' (which is now
  unbound by default.

  *** `x-select-enable-clipboard' now defaults to t on all platforms.
  Thus, killing and yanking now use the clipboard (in addition to the
  kill ring).  Note that this variable was already non-nil by default on
  MS-Windows, which does not support the primary selection between
  applications.

  *** `x-select-enable-primary' now defaults to nil.
  This variable exists only on X; its default value was t in previous
  versions.

  *** `mouse-drag-copy-region' now defaults to nil.
  Its previous default value was t.

  *** Support for X cut buffers has been removed.