From 29e2eaed26a2631a3eeabbf71230d9ffaddf3360 Mon Sep 17 00:00:00 2001
From: Akihiko Odaki <akihiko.odaki@gmail.com>
Date: Sun, 14 Jul 2024 15:54:27 +0900
Subject: [PATCH] Require syslog only when necessary

Requiring syslog on Ruby 3.3.0 results in an warning if the gem is not
explicitly installed. Suppress it by requiring syslog only when the user
tries to use Logging::Appender::Syslog.
---
 lib/logging.rb                  |  7 -------
 lib/logging/appenders.rb        | 14 +++++++++++++-
 lib/logging/appenders/syslog.rb | 14 +-------------
 test/appenders/test_syslog.rb   |  7 +++++++
 4 files changed, 21 insertions(+), 21 deletions(-)

diff --git a/lib/logging.rb b/lib/logging.rb
index eb4668ad..8620d6cc 100644
--- a/lib/logging.rb
+++ b/lib/logging.rb
@@ -6,13 +6,6 @@
 require 'little-plugger'
 require 'multi_json'
 
-begin
-  require 'syslog'
-  HAVE_SYSLOG = true
-rescue LoadError
-  HAVE_SYSLOG = false
-end
-
 #
 #
 module Logging
diff --git a/lib/logging/appenders.rb b/lib/logging/appenders.rb
index f221f8f1..119059dd 100644
--- a/lib/logging/appenders.rb
+++ b/lib/logging/appenders.rb
@@ -47,8 +47,21 @@ def reset
     end
     # :startdoc:
 
+    # Accessor / Factory for the Syslog appender.
+    #
+    def self.syslog( *args )
+      fail ArgumentError, '::Logging::Appenders::Syslog needs a name as first argument.' if args.empty?
+      ::Logging::Appenders::Syslog.new(*args)
+    end
+
     extend self
     @appenders = Hash.new
+
+    # Load Syslog only when requested. Windows does not have syslog, and
+    # Ruby 3.4.0 will remove it from the standard library. Requiring
+    # syslog on Ruby 3.3.0 will result in an warning if the gem is not
+    # explicitly installed.
+    autoload :Syslog, Logging.libpath('logging/appenders/syslog')
   end  # Appenders
 
   require libpath('logging/appenders/buffering')
@@ -57,6 +70,5 @@ def reset
   require libpath('logging/appenders/file')
   require libpath('logging/appenders/rolling_file')
   require libpath('logging/appenders/string_io')
-  require libpath('logging/appenders/syslog')
 end  # Logging
 
diff --git a/lib/logging/appenders/syslog.rb b/lib/logging/appenders/syslog.rb
index 818e0b44..387d4a82 100644
--- a/lib/logging/appenders/syslog.rb
+++ b/lib/logging/appenders/syslog.rb
@@ -1,18 +1,7 @@
-
-# only load this class if we have the syslog library
-# Windows does not have syslog
-#
-if HAVE_SYSLOG
+require 'syslog'
 
 module Logging::Appenders
 
-  # Accessor / Factory for the Syslog appender.
-  #
-  def self.syslog( *args )
-    fail ArgumentError, '::Logging::Appenders::Syslog needs a name as first argument.' if args.empty?
-    ::Logging::Appenders::Syslog.new(*args)
-  end
-
   # This class provides an Appender that can write to the UNIX syslog
   # daemon.
   #
@@ -211,4 +200,3 @@ def syslog_level_num( level )
 
   end  # Syslog
 end  # Logging::Appenders
-end  # HAVE_SYSLOG
diff --git a/test/appenders/test_syslog.rb b/test/appenders/test_syslog.rb
index 7411f458..14962be5 100644
--- a/test/appenders/test_syslog.rb
+++ b/test/appenders/test_syslog.rb
@@ -1,6 +1,13 @@
 
 require File.expand_path('../setup', File.dirname(__FILE__))
 
+begin
+  require 'syslog'
+  HAVE_SYSLOG = true
+rescue LoadError
+  HAVE_SYSLOG = false
+end
+
 if HAVE_SYSLOG
 
 module TestLogging