* cont.c (fiber_t_alloc): raise an error when fiber is going to be

  initialized twice.  [ruby-dev:42524]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@29682 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 4 insertions, 0 deletions

diff --git a/cont.c b/cont.c
index b0defcaeb7..56ae843d73 100644
--- a/cont.c
+++ b/cont.c
@@ -971,6 +971,10 @@ fiber_t_alloc(VALUE fibval)
     rb_fiber_t *fib;
     rb_thread_t *th = GET_THREAD();
 
+    if (DATA_PTR(fibval) != 0) {
+	rb_raise(rb_eRuntimeError, "cannot initialize twice");
+    }
+
     THREAD_MUST_BE_RUNNING(th);
     fib = ALLOC(rb_fiber_t);
     memset(fib, 0, sizeof(rb_fiber_t));