* cont.c (fiber_switch): ignore fiber context switch

  because destination fiber is same as current fiber.
  With out this, it may segv on FreeBSD 9.
  patched by Koichi Sasada.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@33804 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 7 insertions, 0 deletions

diff --git a/cont.c b/cont.c
index cb934f79bc..34cc170334 100644
--- a/cont.c
+++ b/cont.c
@@ -1260,6 +1260,13 @@ fiber_switch(VALUE fibval, int argc, VALUE *argv, int is_resume)
     GetFiberPtr(fibval, fib);
     cont = &fib->cont;
 
+    if (th->fiber == fibval) {
+	/* ignore fiber context switch
+         * because destination fiber is same as current fiber
+	 */
+	return make_passing_arg(argc, argv);
+    }
+
     if (cont->saved_thread.self != th->self) {
 	rb_raise(rb_eFiberError, "fiber called across threads");
     }