* cont.c (fiber_switch): raise FiberError when returning to dead

fiber.  [ruby-dev:40833]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@27713 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Mon May 10 02:29:51 2010  Yusuke Endoh  <mame@tsg.ne.jp>
+
+	* cont.c (fiber_switch): raise FiberError when returning to dead
+	  fiber.  [ruby-dev:40833]
+
 Mon May 10 02:07:20 2010  Yusuke Endoh  <mame@tsg.ne.jp>
 
 	* lib/thread.rb (ConditionVariable#wait): ensure to remove the current

cont.c

@@ -1239,9 +1239,15 @@ fiber_switch(VALUE fibval, int argc, VALUE *argv, int is_resume)
     }
     else if (fib->status == TERMINATED) {
 	value = rb_exc_new2(rb_eFiberError, "dead fiber called");
-	if (th->fiber != fibval) rb_exc_raise(value);
+	if (th->fiber != fibval) {
+	    GetFiberPtr(th->fiber, fib);
+	    if (fib->status != TERMINATED) rb_exc_raise(value);
+	    fibval = th->root_fiber;
+	}
+	else {
 	    fibval = fib->prev;
 	    if (NIL_P(fibval)) fibval = th->root_fiber;
+	}
 	GetFiberPtr(fibval, fib);
 	cont = &fib->cont;
 	cont->argc = -1;

test/ruby/test_fiber.rb

@@ -1,6 +1,7 @@
 require 'test/unit'
 require 'fiber'
 require 'continuation'
+require_relative './envutil'
 
 class TestFiber < Test::Unit::TestCase
   def test_normal
@@ -178,5 +179,15 @@ class TestFiber < Test::Unit::TestCase
     f = Fiber.new {f.resume}
     assert_raise(FiberError, '[ruby-core:23651]') {f.transfer}
   end
+
+  def test_fiber_transfer_segv
+    assert_normal_exit %q{
+      require 'fiber'
+      f2 = nil
+      f1 = Fiber.new{ f2.resume }
+      f2 = Fiber.new{ f1.resume }
+      f1.transfer
+    }
+  end
 end