Fix issue with Kernel#silence_stream leaking file descriptors

Calling Kernel#silence_stream creates a new file descriptor which isn't
closed after it is used. As a result calling silence_stream multiple
times leads to a build up of loose file descriptors and can cause issues
in environments where garbage collection isn't run often.

1 files changed, 16 insertions, 0 deletions

diff --git a/activesupport/test/core_ext/kernel_test.rb b/activesupport/test/core_ext/kernel_test.rb
index b8951de402..18b251173f 100644
--- a/activesupport/test/core_ext/kernel_test.rb
+++ b/activesupport/test/core_ext/kernel_test.rb
@@ -38,6 +38,22 @@ class KernelTest < ActiveSupport::TestCase
     # Skip if we can't STDERR.tell
   end
 
+  def test_silence_stream
+    old_stream_position = STDOUT.tell
+    silence_stream(STDOUT) { STDOUT.puts 'hello world' }
+    assert_equal old_stream_position, STDOUT.tell
+  rescue Errno::ESPIPE
+    # Skip if we can't stream.tell
+  end
+
+  def test_silence_stream_closes_file_descriptors
+    stream     = StringIO.new
+    dup_stream = StringIO.new
+    stream.stubs(:dup).returns(dup_stream)
+    dup_stream.expects(:close)
+    silence_stream(stream) { stream.puts 'hello world' }
+  end
+
   def test_quietly
     old_stdout_position, old_stderr_position = STDOUT.tell, STDERR.tell
     quietly do