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

[Po Lu via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Lars Ingebrigtsen <larsi@gnus.org> writes:

> Now I'm seeing this phenomenon, too, but I don't have a recipe to
> reproduce it either.  But this Emacs has two frames, and if I select one
> of the frames, and then select a frame from a different Emacs that
> covers this frame, then both the other Emacs and this Emacs has a
> blinking cursor.
>
> If I select the frames in a different sequence, then the non-selected
> Emacs frame stops blinking.
>
> So it seems like there some sort of interaction between frames being
> hidden and frames not noticing that they've lost focus?  But I'm unable
> to reproduce this from "emacs -Q".
>
> I've added Po Lu to the CCs; perhaps he has some comments here.  In
> particular -- have there been any changes in the code that notices
> getting/losing focus lately?

Yes -- only under the GTK 3 and no toolkit builds, where the focus code
was rewritten from scratch in order to not crash under X environments
with multiple pointers.

I will look into this, thanks.