bug#141: Process sentinel not called in batch mode

[Eli Zaretskii]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: rms@gnu.org,  141@emacsbugs.donarmstrong.com,  cyd@stupidchicken.com,  
> eller.helmut@gmail.com,  emacs-devel@gnu.org,  
> bug-submit-list@donarmstrong.com,  bug-gnu-emacs@gnu.org
> Date: Fri, 16 May 2008 15:24:04 -0400
> 
> >> >> This side I understand, but what about the other: why should we not
> >> >> check process status in the case where we are not redisplaying?
> >> 
> >> > Because Emacs generally looks at process output only when it's idle?
> >> 
> >> I don't follow: we're talking about when should
> >> wait_reading_process_output check status_notify.
> >> 
> >> So to repeat/rephrase my question: why doesn't
> >> wait_reading_process_output call status_notify when it is passed a zero
> >> do_display?
> 
> > Sorry, let me explain my line of thought in more detail: Emacs only
> > does a redisplay when it is idle.  Emacs also checks input from
> > subprocesses when it is idle.  If we are not in redisplay, it means
> > Emacs is not idle, and so it makes sense not to check for subprocess
> > output at that time.
> 
> > Does this make any sense?
> 
> But if we're in wait_reading_process_output, that means that idle or
> not, we're checking for process output, so why not check for process
> status changes as well?

Because status_notify has a side effect of triggering redisplay.