* thread.c (thread_create_core): prohibit thread creation in the

frozen thread group.  a patch in [ruby-dev:33176] from sheepman
  <sheepman AT sheepman.sakura.ne.jp>.

* thread.c (thread_create_core): should inherit ThreadGroup from
  the current thread.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@15118 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/ruby/test_thread.rb

@@ -22,3 +22,36 @@ class TestThread < Test::Unit::TestCase
   end
 end
 
+class TestThreadGroup < Test::Unit::TestCase
+  def test_thread_init
+    thgrp = ThreadGroup.new
+    Thread.new{
+      thgrp.add(Thread.current)
+      assert_equal(thgrp, Thread.new{sleep 1}.group)
+    }.join
+  end
+
+  def test_frozen_thgroup
+    thgrp = ThreadGroup.new
+    Thread.new{
+      thgrp.add(Thread.current)
+      thgrp.freeze
+      assert_raise(ThreadError) do
+        Thread.new{1}.join
+      end
+    }.join
+  end
+
+  def test_enclosed_thgroup
+    thgrp = ThreadGroup.new
+    thgrp.enclose
+    Thread.new{
+      assert_raise(ThreadError) do
+        thgrp.add(Thread.current)
+      end
+      assert_nothing_raised do
+        Thread.new{1}.join
+      end
+    }.join
+  end
+end