bug#13400: 23.4; overlapping process filter calls

[Eli Zaretskii <eliz@gnu.org>]

> From: Noam Postavsky <npostavs@gmail.com>
> Date: Fri, 26 Jul 2019 23:38:46 -0400
> Cc: 13400@debbugs.gnu.org, Stefan Monnier <monnier@iro.umontreal.ca>
> 
> > - Section "37.9 Receiving Output from Processes" does not list
> >   process-send-string. How about other blocking I/O functions?
> 
> In the attached patch, I've added a mention/xref for functions which send
> data to processes.
> 
> > - Same in "37.9.2. Process Filter Functions"
> 
> This section is repeated twice (I addressed the second instance below).
> 
> > - Same in "37.4 Creating an Asynchronous Process" ,
> >   process-send-string is neither waiting for input not time
> >   delay.
> 
> I don't see any mention of process-send-string in that section, nor how
> it's relevant to the rest of this report.
> 
> > - "37.7 Sending Input to Processes" says that filters can run
> >   inside process-send-string, but it could be clearer about the
> >   point that this can also happen inside the same filter for the
> >   same process.
> 
> I'm not really convinced that is necessary.
> 
> > - "37.9.2 Process Filter Functions" ignores the problem
> >   completely. There should be a paragraph clearly stating this
> >   problem. Further, it would be nice, if the filter function
> >   example could be extended to correctly deal with this problem.
> 
> I added a mention of the possibility of recursion.  I'm not sure about
> making an example (specifically, what is the best way to deal with this
> problem?).

I agree with Noam's decisions, and think that his patch is fine.

Thanks.