Comment 47 for bug 1974214

I still can't duplicate the ARC-case segv. However, I did identify a lack
of re-initialization that might be relevant. Please add, at about
"src/arc.c" line 1532 :-

headers_rlist = NULL;

(I've managed a testcase for the non-ARC case; it doesn't consistently segv
on my platform but does, before the fix, consistently have identifiably bad
behavior).