Re: call-process should not block process filters from running

[Po Lu <luangruo@yahoo.com>]

sbaugh@catern.com writes:

> However, my other main test case/use case, being able to paste while
> Emacs is in call-process, doesn't work with this change.  Any idea on
> how to make that work?

By entering the command loop or by calling `process_special_events'
every time wait_reading_process_input returns.  I don't recommend doing
either from call_process: a lot of existing code relies on Lisp code not
running inside calls to that function, and errors inside selection
handlers will be signaled even if nothing's wrong with the process being
called.

Also, you should at least check that call_process is reentrant: it must
be able to handle calls to itself made by any timers or selection
handlers that run within the process input loop, with the processes
being called completing in any order.