🚀 go-pugleaf

In article <9012171301.AA14222@iesd.auc.dk> amanda@IESD.AUC.DK (Per Abrahamsen) writes:

> Emacs dumps core with signal 3 when it you press the following keys
> fast after each other:
> 
>	   C-z C-\
> 
> This is a problem on a terminal, where these keys are placed next to
> each other.  

The current issue of CACM contains an article on "buggy" Unix programs
that describes this problem.  The above behavior is a race condition.
Specifically, ^Z directs emacs to suspend itself, which requires
resetting the terminal driver to its default state (e.g., so that ^H,
^C, etc. are interpreted by the device driver rather than the running
application).  Emacs then sends itself a SIGTSTP to actually suspend
itself.  There is a small window between resetting the terminal driver
and becoming suspended.  If the user types C-\ during this window, the
terminal driver sends emacs a SIGQUIT, which by definition cannot be
ignored.

There appears no easy solution.  No matter what one does, there will
always be a small window after the terminal driver has been reset but
before the emacs process has actually become suspended, during which
time it is vulnerable to a SIGQUIT generated in response to C-\.
--
Thomas Narten
narten@cs.albany.edu