Re: "no duplicate" in `popen.test'

[Neil Jerram]

address@hidden (Ludovic Courtès) writes:

> Hello,
>
> That "no duplicate" test in `popen.test' leaves a zombie behind it [0].
> The fix would be to `waitpid' the process created by `open-input-pipe'
> (see attached patch), but that makes it hang, waiting for "sleep 999" to
> complete.

I've attached an alternative possible solution, using feedback from
the parent to the child to avoid needing the long sleep.

Unfortunately, though, I didn't manage to observe the zombie process
with the test as it was before.  (How do I do this on GNU/Linux?)  So
I don't really know whether this is a significant improvement.

> I'm not sure whether it's an indication that the bug was caught, or
> rather an indication that the test is broken, especially since I don't
> fully understand the bug that it's trying to catch.

If waitpid fixes it, doesn't that point to the test being broken?

> I would appreciate feedback on this since it's tempting to remove it
> altogether for all the harm it's done.  ;-)

It seems a worthwhile test to me.  I'd rather work on a tricky
test like this, than on a report of a problem in the context of a
whole application (but which eventually boiled down to the same
thing).

I'm also interested in the forking/threads issue (which is now fixed,
if I've understood the cited thread correctly), and wouldn't want to
remove a test that covered that, unless we can devise a more specific
test for just that issue.

Regards,
        Neil

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