"John Wiegley" <johnw@gnu.org> writes:

>>>>>> Spencer Baugh <sbaugh@janestreet.com> writes:
>
>> (while (null (accept-process-output proc2)))
>
> Based on the what the manual says, shouldn’t this be?
>
>     (while (accept-process-output proc2))

No, I'm trying to run accept-process-output repeatedly until proc2
produces any output at all, which will cause accept-process-output to
return non-nil.

>> Anyway, probably we should be setting fd_callback_info[fd].thread to
>> NULL also when the process exits.  But, I suggest we should further also
>> set it to NULL (and also waiting_thread) when we start using a
>> fd_callback_info[fd] slot, e.g. in add_read_fd.  That avoids the
>> possibility of permanent contamination of fd_callback_info slots, which
>> I think is possible in some other ways, though I haven't been able to
>> reproduce it yet...
>
> This sounds like an important fix to me. I haven’t run into this problem yet
> myself, but the logic above tracks.

Here's a patch to fix it by initializing these fields.