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

[Bob Rogers]

   From: Lars Ingebrigtsen <larsi@gnus.org>
   Date: Wed, 31 Aug 2022 12:03:38 +0200

   Bob Rogers <rogers@rgrjr.com> writes:

   >    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.

   How was the root Emacs started?  Could it be in a way that stops the
   window manager from delivering events to it?

Just "emacs &" after "su" in a shell.  I should emphasize that I've seen
nothing special about the root emacs; all instances save one switched
between working and nonworking at long but unpredictable intervals.  And
the other problematic instances were also spawned from shells, though
some were from a Konsole shell, some were via ssh with tunneled X11, and
some from an emacs shell window.

   I've also tried a slightly newer version of master (commit
136495f178ccd36b23ffc347fe2b6680fd689e34) on the previous openSUSE
release, and the cursor behaves normally WRT focus-in/out.  Here's what
report-emacs-bug says about the installation:

        Windowing system distributor 'The X.Org Foundation', version 
11.0.12003000
        System Description: openSUSE Leap 15.3

This is under KDE/Plasma, apparently version 5.18.5.

                                        -- Bob