bug#11191: C-x C-x does not activate the selection anymore with cua-selection-mode

[Kim Storm <storm@cua.dk>]

On 04/09/2012 07:50 AM, Dan Nicolaescu wrote:
> Chong Yidong<cyd@gnu.org>  writes:
>
>> Dan Nicolaescu<dann@gnu.org>  writes:
>>
>> [recipe edited]
>>
>>> emacs -Q
>>> M-x cua-selection-mode RET
>>> M-<
>>> C-SPC C-f C-f C-f C-g
>>> C-x C-x
>>>
>>> now the selection should be active, but it is not.
>>> This worked in emacs-23.3, so this is a regression.
>> Looks like this change was made deliberately:
>>
>>    revno: 102844
>>    committer: Kim F. Storm<storm@cua.dk>
>>    branch nick: trunk
>>    timestamp: Fri 2011-01-14 16:06:17 +0100
>>    message:
>>    * emulation/cua-base.el (cua--init-keymaps):
>>    Remap exchange-point-and-mark in cua-global-keymap.
>>
>> The docstring of `cua-exchange-point-and-mark' says it does not activate
>> the mark.
>> Kim, could you confirm that this was the intention?
>
> In emacs-22.3 and 23.3 it does activate the mark.
> C-x C-x also activates the mark in the trunk without
> cua-selection-mode.
>
> Wouldn't it be better that instead of changing something that has been
> present in two major releases and is consistent with the default behavior,
> to change the docstring?
>

The current behaviour is "by design"

Personally, I find it very annoying if C-x C-x activates the mark with 
cua-mode - as it becomes very
hard to enter another C-x C-x to cancel it (it actually requires three 
C-x typed rapidly -- otherwise
it will delete the region.  That is why cua-exchange-point-and-mark 
doesn't activate the mark
by default.

- but with reference to bug #6199 on the same subject,  I have already 
approved to change the behaviour
--- if anyone feels it is necessary.

I think the following version should do the trick

(defun cua-exchange-point-and-mark (arg)
   "Exchanges point and mark.
Don't activate the mark if a prefix argument is given."
   (interactive "P")
   (let ((ma mark-active))
     (exchange-point-and-mark)
     (if cua--rectangle
     (cua--rectangle-corner 0))
     (if arg
     (setq mark-active ma))))