bug#57468: 29.0.50; Text cursor continues to blink when frame loses focus

[Bob Rogers]

   From: Eli Zaretskii <eliz@gnu.org>
   Date: Tue, 30 Aug 2022 15:02:17 +0300

   > Cc: 57468@debbugs.gnu.org
   > From: Lars Ingebrigtsen <larsi@gnus.org>
   > Date: Tue, 30 Aug 2022 12:27:00 +0200
   > 
   > Could it be the window manager that's not sending Emacs the de-focus
   > event (or whatever it's called)?

   That should be easy to verify by binding a command to the event that
   will display the event.  The focus-in "pseudo-key" is defined in the
   special-event-map.

When I went back to my console, I found to my consternation that two
local emacs instances plus a new "src/emacs -Q" all behaved correctly,
despite not having touched anything since my last email that might
conceivably have an effect.  Persevering, I used the following code to
track events:

        (defun rgr-focus-in () (interactive) (message "focus in"))
        (define-key special-event-map [ focus-in ] 'rgr-focus-in)
        (defun rgr-focus-out () (interactive) (message "focus out"))
        (define-key special-event-map [ focus-out ] 'rgr-focus-out)

And got the expected correct behavior.

   Then I brought up a pre-existing emacs instance running as root
(which I had forgotten about) and found that its blinking cursor stays
on persistently, and the focus in/out code above shows that it's getting
neither event.  (I don't remember if I tested this instance when
reporting the bug two days ago, but I suspect I did and that it was
normal.)

                                        -- Bob