[PATCH] Use deactivate-mark from cua-cancel

[PATCH] Use deactivate-mark from cua-cancel

[Andrew Burgess]

Create a config file ~/tmp/setup.el containing:

  (defun cursor-activate-mark ()
     (setq cursor-type 'bar))
  (add-hook 'activate-mark-hook 'cursor-activate-mark)

  (defun cursor-deactivate-mark ()
     (setq cursor-type 'box))
  (add-hook 'deactivate-mark-hook 'cursor-deactivate-mark)

Start emacs like this:

  emacs -Q -l ~/tmp/setup.el ~/tmp/setup.el

Now do the following:

  M-x set-mark-command
  M-x forward-paragraph
  C-g

You should see that after `set-mark-command` the cursor changes from
box to bar, then after the C-g (`keyboard-quit`) the cursor changes
back to box.

Now do:

  M-x cua-selection-mode
  M-x set-mark-command
  M-x forward-paragraph
  C-g

In this case the cursor should still change from box to bar when the
mark is set, but after the C-g the cursor will be left as a bar.

The reason is that with `cua-selection-mode` enabled, C-g now calls
`cua-cancel` instead of `keyboard-quit`.  Currently `cua-cancel` looks
like this:

  (defun cua-cancel ()
    "Cancel the active region, rectangle, or global mark."
    (interactive)
    (setq mark-active nil)
    (if (fboundp 'cua--cancel-rectangle)
        (cua--cancel-rectangle)))

It is the line:

    (setq mark-active nil)

that is problematic, setting `mark-active` directly avoids the
`deactivate-mark-hook`.  I think that instead we should be calling
`deactivate-mark`, and this is what this patch does.

* lisp/emulation/cua-base.el (cua-cancel): Use deactivate-mark
instead of setting mark-active directly.
---
 lisp/emulation/cua-base.el | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lisp/emulation/cua-base.el b/lisp/emulation/cua-base.el
index 26a1a8955f..c4dcb76446 100644
--- a/lisp/emulation/cua-base.el
+++ b/lisp/emulation/cua-base.el
@@ -860,7 +860,7 @@ With numeric prefix arg, copy to register 0-9 instead."
 (defun cua-cancel ()
   "Cancel the active region, rectangle, or global mark."
   (interactive)
-  (setq mark-active nil)
+  (deactivate-mark)
   (if (fboundp 'cua--cancel-rectangle)
       (cua--cancel-rectangle)))
 
-- 
2.25.4

Re: [PATCH] Use deactivate-mark from cua-cancel

[Eli Zaretskii]

> From: Andrew Burgess <andrew.burgess@embecosm.com>
> Date: Sun,  7 Jun 2020 09:20:19 +0100
> Cc: Andrew Burgess <andrew.burgess@embecosm.com>
> 
> The reason is that with `cua-selection-mode` enabled, C-g now calls
> `cua-cancel` instead of `keyboard-quit`.  Currently `cua-cancel` looks
> like this:
> 
>   (defun cua-cancel ()
>     "Cancel the active region, rectangle, or global mark."
>     (interactive)
>     (setq mark-active nil)
>     (if (fboundp 'cua--cancel-rectangle)
>         (cua--cancel-rectangle)))
> 
> It is the line:
> 
>     (setq mark-active nil)
> 
> that is problematic, setting `mark-active` directly avoids the
> `deactivate-mark-hook`.  I think that instead we should be calling
> `deactivate-mark`, and this is what this patch does.

Thanks, pushed to the master branch.