Avoid GCing dead stack after switching away from a fiber

Fixes <https://bugs.ruby-lang.org/issues/14561> and discussed
<https://bugs.ruby-lang.org/issues/15362>.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66111 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 1 insertions, 0 deletions

diff --git a/cont.c b/cont.c
index 142713ad84..da469b6cd5 100644
--- a/cont.c
+++ b/cont.c
@@ -1747,6 +1747,7 @@ fiber_store(rb_fiber_t *next_fib, rb_thread_t *th)
     return fib->cont.value;
 
 #else /* FIBER_USE_NATIVE */
+    fib->cont.saved_ec.machine.stack_end = NULL;
     if (ruby_setjmp(fib->cont.jmpbuf)) {
         /* restored */
         fib = th->ec->fiber_ptr;