Re: long-standing tty related issue: wrapped Emacs not suspended

[Joey Pabalinas <joeypabalinas@xxxxxxxxx>]

On Fri, Sep 21, 2018 at 06:17:47PM -0700, Bart Schaefer wrote:
> FWIW I can't get what Vincent describes to happen at all with the
> above example and the current git checkout, even after assorted
> bg/fg/^Z/etc.  But the system on which I can currently test doesn't
> have an X-enabled emacs.

This did confuse me a bit earlier in Peter's email, as I also had this
exact behavior on 5.5.1.r143.g225b35c9070f94cf79 where -CONT didn't even
seem to work regardless of which child process I sent it to. I had just
chalked it up to one of my weird configs, but I guess this is pretty
much happening to everyone running the development versions?

> Also, the parent shell should probably be sending a SIGCONT to all
> those jobs whenever they are fg'd, even if it believes they are
> already running.  SIGCONT is harmless for a job that is not stopped,
> and trusting the job table idea of the process state is an unnecessary
> optimization.

Interestingly enough I did once run into a program that used a SIGCONT
handler, reset to default disposition in SIGTSTP handler, for some internal
callback-ish stuff. My guess was it assumed SIGCONT to be a "safe" sentinel
signal (while completely forgetting about its uncatchable brother SIGSTOP),
but cases like that are mostly just broken curiosities and definitely not
worth worrying about :)

-- 
Cheers,
Joey Pabalinas

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