* cont.c (cont_init): clear macihne_stack_start/end of saved thread to

   prevent mark machine stack of GC'ed Thread. root Fiber is not initialized by
   fiber_init(). based on a patch by Serge Balyuk [ruby-core:35891] fixes #4612
 * test/ruby/test_fiber.rb (test_gc_root_fiber): add test for it.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@31577 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 1 insertions, 0 deletions

diff --git a/cont.c b/cont.c
index ad277bda1d..9a0593c21e 100644
--- a/cont.c
+++ b/cont.c
@@ -383,6 +383,7 @@ cont_init(rb_context_t *cont, rb_thread_t *th)
     /* save thread context */
     cont->saved_thread = *th;
     cont->saved_thread.local_storage = 0;
+    cont->saved_thread.machine_stack_start = cont->saved_thread.machine_stack_end = 0;
 }
 
 static rb_context_t *