io.c: get rid of race condition

* io.c (rb_io_close_write): detach tied IO for writing before closing
  to get rid of race condition.  [ruby-list:49598]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43114 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 13 insertions, 0 deletions

diff --git a/test/ruby/test_io.rb b/test/ruby/test_io.rb
index e424747734..437e7ae5b5 100644
--- a/test/ruby/test_io.rb
+++ b/test/ruby/test_io.rb
@@ -1380,6 +1380,19 @@ class TestIO < Test::Unit::TestCase
     end
   end
 
+  def test_close_read_write_separately
+    bug = '[ruby-list:49598]'
+    (1..10).each do |i|
+      assert_nothing_raised(IOError, "#{bug} trying ##{i}") do
+        IO.popen(EnvUtil.rubybin, "r+") {|f|
+          th = Thread.new {f.close_write}
+          f.close_read
+          th.join
+        }
+      end
+    end
+  end
+
   def test_pid
     r, w = IO.pipe
     assert_equal(nil, r.pid)