On Thu, Jun 1, 2017 at 11:45 PM, Stefan Beller [off-list ref] wrote:

quoted

I didn't mean to change this bit, it should remain "if
(!num_threads)". I was in the middle of monkeypatching and didn't
review the diff carefully enough. But it any case, without this change
the rest of this diff is your proposed (but segfaulting) change as I
understand it.

Sorry for the proposing a sloppy alternative. (I missed one occurrence
of num_threads used in a conditional).
I think the original is still better than littering comments everywhere.

I should have said: None of these follow-up diffs of mine (including
the added comments) are something I think should be applied, I just
inlined that to explain the code in context.

Just to make 100% sure I understand you, do you mean you think the
original v4 version I posted here makes sense with that explanation or
do you have other outstanding concerns?