[ruby/logger] Let Logger#reopen not raise on nil log devices

https://github.com/ruby/logger/commit/da7bf844e5

lib/logger.rb

@@ -410,7 +410,7 @@ class Logger
   # Reopen a log device.
   #
   def reopen(logdev = nil)
-    @logdev.reopen(logdev)
+    @logdev&.reopen(logdev)
     self
   end
 

test/logger/test_logger.rb

@@ -216,6 +216,13 @@ class TestLogger < Test::Unit::TestCase
     assert_equal(STDOUT, logger.instance_variable_get(:@logdev).dev)
   end
 
+  def test_reopen_nil_logdevice
+    logger = Logger.new(File::NULL)
+    assert_nothing_raised do
+      logger.reopen(STDOUT)
+    end
+  end
+
   def test_add
     logger = Logger.new(nil)
     logger.progname = "my_progname"