bug#13475: 24.2.91; accept-process-output hangs emacs on killed sub-process

[Dmitry Gutov]

On 03.10.2019 20:24, Lars Ingebrigtsen wrote:

> I'm don't think this is a bug -- as you say, if PROC is dead, then we
> just heed the timeout, so in a loop like this, you should check whether
> PROC is alive before calling `accept-process-output'.
>
> So I'm closing this bug report.  I somebody things that Emacs should be
> changed to make accept-process-output to return immediately (with a
> non-nil return value?) if PROC is dead, please reopen.

Shouldn't we consider the "connection" to be "closed" if the process is 
dead? From the docstring:

  Return non-nil if we received any output from PROCESS (or, if PROCESS
  is nil, from any process) before the timeout expired or the
  corresponding connection was closed.

That might also imply that the function should return right away. But 
the example should work correctly even if it waits the required number 
of seconds and then returns non-nil.