Revert "Avoid mutating global STDOUT & STDERR (#1837)" (#1946)

This reverts commit 70b28bb.

lib/puma/events.rb

@@ -29,8 +29,8 @@ def call(str)
     #
     def initialize(stdout, stderr)
       @formatter = DefaultFormatter.new
-      @stdout = stdout.dup
-      @stderr = stderr.dup
+      @stdout = stdout
+      @stderr = stderr
 
       @stdout.sync = true
       @stderr.sync = true

test/test_events.rb

@@ -6,6 +6,7 @@ def test_null
 
     assert_instance_of Puma::NullIO, events.stdout
     assert_instance_of Puma::NullIO, events.stderr
+    assert_equal events.stdout, events.stderr
   end
 
   def test_strings
@@ -18,17 +19,8 @@ def test_strings
   def test_stdio
     events = Puma::Events.stdio
 
-    # events.stdout is a dup, so same file handle, different ruby object, but inspect should show the same file handle
-    assert_equal STDOUT.inspect, events.stdout.inspect
-    assert_equal STDERR.inspect, events.stderr.inspect
-  end
-
-  def test_stdio_respects_sync
-    STDOUT.sync = false
-    events = Puma::Events.stdio
-
-    assert !STDOUT.sync
-    assert events.stdout.sync
+    assert_equal STDOUT, events.stdout
+    assert_equal STDERR, events.stderr
   end
 
   def test_register_callback_with_block

test/test_tcp_logger.rb

@@ -18,7 +18,6 @@ def test_events
     # in lib/puma/launcher.rb:85
     # Puma::Events is default tcp_logger for cluster mode
     logger = Puma::Events.new(STDOUT, STDERR)
-    logger.instance_variable_set(:@stdout, $stdout) # ensure capture_process_io has access to the loggers output
     out, err = capture_subprocess_io do
       Puma::TCPLogger.new(logger, @server.app).call({}, @socket)
     end