bug#65811: 27.1; zzzzzzzz forever

[Eli Zaretskii <eliz@gnu.org>]

> Date: Thu, 7 Sep 2023 20:33:31 +0000
> From:  Bruce Adams via "Bug reports for GNU Emacs,
>  the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
> 
> This bug report concerns issue one which is that sometimes
> my emacs inexplicably starts filling with repeated zzzzzzz characters.
> Though other editing activity is possible inbetween 'attacks'
> 
> This continues even if I unplug the keyboard (to rule out a USB keyboard
> issue).zzzzzzzzzzzzzzzzzzzzzzz
> It is possible to get control back temporarily by changing the window
> size.zzzzzzzzzzzzzz
> The added zzzzz... can be undone using ctrl-u.

When this happens, type "C-h l" and see if Emacs really got those 'z'
characters in its input.  If it did, there's nothing Emacs can do
about it: the OS somehow stuffs those characters into the Emacs input
queue.

> My second issue is that if left running (typically unattended or out of
> focus) for a long time emacs crashes. I will try to add a second bug report
> with a backtrace when this happens.
> I did not have the debug symbols installed for previous occurances but
> it is quite repeatable.

Yes, please, we need backtraces from GDB to try to understand what
could cause these crashes.

> I have a couple of backtraces below for the zzzz issue:

Those backtraces just say that Emacs is idle waiting for input.  They
give no hint about the problem, which is expected if the problem is
outside of Emacs.