bug#24030: 25.0.95; mouse-drag-region regression

[Alex]

Eli Zaretskii <eliz@gnu.org> writes:

> More accurately, it's not the window that was never the selected one,
> it's the buffer that is displayed in it.

Ah, I see.

> And mark-active is nil because some code
> that I was unable to track down sets deactivate-mark to non-nil, so
> the command loop deactivates the mark.

It appears that it's somewhere within select-window or something it
calls. After posn-set-point calls select-window in 24.5, deactivate-mark
is nil -- but it's t in 25.1.

#+BEGIN_SRC elisp
(defun test ()
  (message "before: %s" deactivate-mark)
  (select-window (cadr (window-list)))
  (message "after: %s" deactivate-mark))
#+END_SRC

In the case where the target window contains the new help buffer,
deactivate-mark will be nil in 24.5 and t in 25.1.
> Thanks.