From eac33df8c336ef5ed9263fb4a0a12086a83b5ee3 Mon Sep 17 00:00:00 2001
From: Phil Ross <phil.ross@gmail.com>
Date: Sat, 21 Jan 2023 20:18:15 +0000
Subject: [PATCH] Eliminate Object#untaint deprecation warnings on JRuby
 9.4.0.0.

Despite using the UntaintExt refinement that replaces Object#untaint,
JRuby 9.4.0.0 calls the original Object#untaint method and outputs
warnings as a result:

warning: Object#untaint is deprecated and will be removed in Ruby 3.2

This is caused by the unorthodox `send(:using, UntaintExt)` approach
being used to deal with issues with older JRuby versions (see #114).
JRuby 9.4.0.0 doesn't detect this as using the refinement. This will be
allowed again in JRuby 9.4.1.0 (see jruby/jruby#7599).

Replace the UntaintExt refinement with an untaint method in
RubyCoreSupport (now reinstated having previously been removed in
2.0.0).

Change tests for handling of tainted inputs to skip when taint/untaint
is undefined or a no-op. There's no point in running these tests unless
the inputs are actually tainted. Remove the (test-only) TaintExt
refinement too.

Resolves #145.
---
 lib/tzinfo.rb                                 |  8 +---
 .../data_sources/posix_time_zone_parser.rb    |  8 +---
 lib/tzinfo/data_sources/ruby_data_source.rb   |  6 +--
 .../data_sources/zoneinfo_data_source.rb      |  6 +--
 lib/tzinfo/data_sources/zoneinfo_reader.rb    |  6 +--
 lib/tzinfo/ruby_core_support.rb               | 38 +++++++++++++++++++
 lib/tzinfo/untaint_ext.rb                     | 18 ---------
 .../data_sources/tc_posix_time_zone_parser.rb |  6 +--
 test/data_sources/tc_ruby_data_source.rb      | 12 ++++--
 test/data_sources/tc_zoneinfo_data_source.rb  | 19 ++++++----
 test/data_sources/tc_zoneinfo_reader.rb       | 10 ++---
 test/tc_country.rb                            | 10 +++--
 test/tc_ruby_core_support.rb                  | 19 ++++++++++
 test/tc_timezone.rb                           | 10 +++--
 test/test_utils.rb                            | 30 ++++++++++-----
 test/ts_all_zoneinfo.rb                       |  2 +-
 16 files changed, 125 insertions(+), 83 deletions(-)
 create mode 100644 lib/tzinfo/ruby_core_support.rb
 delete mode 100644 lib/tzinfo/untaint_ext.rb
 create mode 100644 test/tc_ruby_core_support.rb

diff --git a/lib/tzinfo.rb b/lib/tzinfo.rb
index b1b53449..dc8e0856 100644
--- a/lib/tzinfo.rb
+++ b/lib/tzinfo.rb
@@ -17,12 +17,8 @@ def eager_load!
   end
 end
 
-# Object#untaint is a deprecated no-op in Ruby >= 2.7 and will be removed in
-# 3.2. Add a refinement to either silence the warning, or supply the method if
-# needed.
-if !Object.new.respond_to?(:untaint) || RUBY_VERSION =~ /\A(\d+)\.(\d+)(?:\.|\z)/ && ($1 == '2' && $2.to_i >= 7 || $1.to_i >= 3)
-  require_relative 'tzinfo/untaint_ext'
-end
+
+require_relative 'tzinfo/ruby_core_support'
 
 require_relative 'tzinfo/version'
 
diff --git a/lib/tzinfo/data_sources/posix_time_zone_parser.rb b/lib/tzinfo/data_sources/posix_time_zone_parser.rb
index b3d2b2e3..5583b43e 100644
--- a/lib/tzinfo/data_sources/posix_time_zone_parser.rb
+++ b/lib/tzinfo/data_sources/posix_time_zone_parser.rb
@@ -4,10 +4,6 @@
 require 'strscan'
 
 module TZInfo
-  # Use send as a workaround for erroneous 'wrong number of arguments' errors
-  # with JRuby 9.0.5.0 when calling methods with Java implementations. See #114.
-  send(:using, UntaintExt) if TZInfo.const_defined?(:UntaintExt)
-
   module DataSources
     # An {InvalidPosixTimeZone} exception is raised if an invalid POSIX-style
     # time zone string is encountered.
@@ -43,12 +39,12 @@ def parse(tz_string)
 
         s = StringScanner.new(tz_string)
         check_scan(s, /([^-+,\d<][^-+,\d]*) | <([^>]+)>/x)
-        std_abbrev = @string_deduper.dedupe((s[1] || s[2]).untaint)
+        std_abbrev = @string_deduper.dedupe(RubyCoreSupport.untaint(s[1] || s[2]))
         check_scan(s, /([-+]?\d+)(?::(\d+)(?::(\d+))?)?/)
         std_offset = get_offset_from_hms(s[1], s[2], s[3])
 
         if s.scan(/([^-+,\d<][^-+,\d]*) | <([^>]+)>/x)
-          dst_abbrev = @string_deduper.dedupe((s[1] || s[2]).untaint)
+          dst_abbrev = @string_deduper.dedupe(RubyCoreSupport.untaint(s[1] || s[2]))
 
           if s.scan(/([-+]?\d+)(?::(\d+)(?::(\d+))?)?/)
             dst_offset = get_offset_from_hms(s[1], s[2], s[3])
diff --git a/lib/tzinfo/data_sources/ruby_data_source.rb b/lib/tzinfo/data_sources/ruby_data_source.rb
index 9c123225..41c384a4 100644
--- a/lib/tzinfo/data_sources/ruby_data_source.rb
+++ b/lib/tzinfo/data_sources/ruby_data_source.rb
@@ -2,10 +2,6 @@
 # frozen_string_literal: true
 
 module TZInfo
-  # Use send as a workaround for erroneous 'wrong number of arguments' errors
-  # with JRuby 9.0.5.0 when calling methods with Java implementations. See #114.
-  send(:using, UntaintExt) if TZInfo.const_defined?(:UntaintExt)
-
   module DataSources
     # A {TZInfoDataNotFound} exception is raised if the tzinfo-data gem could
     # not be found (i.e. `require 'tzinfo/data'` failed) when selecting the Ruby
@@ -52,7 +48,7 @@ def initialize
           data_file = File.join('', 'tzinfo', 'data.rb')
           path = $".reverse_each.detect {|p| p.end_with?(data_file) }
           if path
-            @base_path = File.join(File.dirname(path), 'data').untaint
+            @base_path = RubyCoreSupport.untaint(File.join(File.dirname(path), 'data'))
           else
             @base_path = 'tzinfo/data'
           end
diff --git a/lib/tzinfo/data_sources/zoneinfo_data_source.rb b/lib/tzinfo/data_sources/zoneinfo_data_source.rb
index cf77576f..4b7de32c 100644
--- a/lib/tzinfo/data_sources/zoneinfo_data_source.rb
+++ b/lib/tzinfo/data_sources/zoneinfo_data_source.rb
@@ -2,10 +2,6 @@
 # frozen_string_literal: true
 
 module TZInfo
-  # Use send as a workaround for erroneous 'wrong number of arguments' errors
-  # with JRuby 9.0.5.0 when calling methods with Java implementations. See #114.
-  send(:using, UntaintExt) if TZInfo.const_defined?(:UntaintExt)
-
   module DataSources
     # An {InvalidZoneinfoDirectory} exception is raised if {ZoneinfoDataSource}
     # is initialized with a specific zoneinfo path that is not a valid zoneinfo
@@ -444,7 +440,7 @@ def enum_timezones(dir, exclude = [], &block)
           end
 
           unless entry =~ /\./ || exclude.include?(entry)
-            entry.untaint
+            RubyCoreSupport.untaint(entry)
             path = dir + [entry]
             full_path = File.join(@zoneinfo_dir, *path)
 
diff --git a/lib/tzinfo/data_sources/zoneinfo_reader.rb b/lib/tzinfo/data_sources/zoneinfo_reader.rb
index ac82585c..7f598875 100644
--- a/lib/tzinfo/data_sources/zoneinfo_reader.rb
+++ b/lib/tzinfo/data_sources/zoneinfo_reader.rb
@@ -2,10 +2,6 @@
 # frozen_string_literal: true
 
 module TZInfo
-  # Use send as a workaround for erroneous 'wrong number of arguments' errors
-  # with JRuby 9.0.5.0 when calling methods with Java implementations. See #114.
-  send(:using, UntaintExt) if TZInfo.const_defined?(:UntaintExt)
-
   module DataSources
     # An {InvalidZoneinfoFile} exception is raised if an attempt is made to load
     # an invalid zoneinfo file.
@@ -448,7 +444,7 @@ def parse(file)
           abbrev_end = abbrev.index("\0", abbrev_start)
           raise InvalidZoneinfoFile, "Missing abbreviation null terminator in file '#{file.path}'." unless abbrev_end
 
-          abbr = @string_deduper.dedupe(abbrev[abbrev_start...abbrev_end].force_encoding(Encoding::UTF_8).untaint)
+          abbr = @string_deduper.dedupe(RubyCoreSupport.untaint(abbrev[abbrev_start...abbrev_end].force_encoding(Encoding::UTF_8)))
 
           TimezoneOffset.new(base_utc_offset, std_offset, abbr)
         end
diff --git a/lib/tzinfo/ruby_core_support.rb b/lib/tzinfo/ruby_core_support.rb
new file mode 100644
index 00000000..9e43e3c9
--- /dev/null
+++ b/lib/tzinfo/ruby_core_support.rb
@@ -0,0 +1,38 @@
+module TZInfo
+
+  # Methods to support different versions of Ruby.
+  #
+  # @private
+  module RubyCoreSupport #:nodoc:
+    class << self
+      # Object#untaint is deprecated and becomes a no-op in Ruby >= 2.7. It has
+      # been removed from Ruby 3.2.
+      if !Object.new.respond_to?(:untaint) || RUBY_VERSION =~ /\A(\d+)\.(\d+)(?:\.|\z)/ && ($1 == '2' && $2.to_i >= 7 || $1.to_i >= 3)
+        # :nocov_functional_untaint:
+
+        # Returns the supplied `Object`
+        #
+        # @param o [Object] the `Object` to untaint.
+        # @return [Object] `o`.
+        def untaint(o)
+          o
+        end
+
+        # :nocov_functional_untaint:
+      else
+        # :nocov_no_functional_untaint:
+
+        # Untaints and returns the supplied `Object`.
+        #
+        # @param o [Object] the `Object` to untaint.
+        # @return [Object] `o`.
+        def untaint(o)
+          o.untaint
+        end
+
+        # :nocov_no_functional_untaint:
+      end
+    end
+  end
+  private_constant :RubyCoreSupport
+end
diff --git a/lib/tzinfo/untaint_ext.rb b/lib/tzinfo/untaint_ext.rb
deleted file mode 100644
index 4e8d0c07..00000000
--- a/lib/tzinfo/untaint_ext.rb
+++ /dev/null
@@ -1,18 +0,0 @@
-# encoding: UTF-8
-# frozen_string_literal: true
-
-module TZInfo
-  # Object#untaint is deprecated in Ruby >= 2.7 and will be removed in 3.2.
-  # UntaintExt adds a refinement to make Object#untaint a no-op and avoid the
-  # warning.
-  #
-  # @private
-  module UntaintExt # :nodoc:
-    refine Object do
-      def untaint
-        self
-      end
-    end
-  end
-  private_constant :UntaintExt
-end
diff --git a/test/data_sources/tc_posix_time_zone_parser.rb b/test/data_sources/tc_posix_time_zone_parser.rb
index 73dbb747..57bf5d9c 100644
--- a/test/data_sources/tc_posix_time_zone_parser.rb
+++ b/test/data_sources/tc_posix_time_zone_parser.rb
@@ -3,10 +3,6 @@
 
 require_relative '../test_utils'
 
-# Use send as a workaround for erroneous 'wrong number of arguments' errors with
-# JRuby 9.0.5.0 when calling methods with Java implementations. See #114.
-send(:using, TestUtils::TaintExt) if TestUtils.const_defined?(:TaintExt)
-
 module DataSources
   class TCPosixTimeZoneParser < Minitest::Test
     include TZInfo
@@ -259,6 +255,8 @@ def test_returns_deduped_strings
     end
 
     def test_parses_tainted_string_in_safe_mode_and_returns_untainted_abbreviations
+      skip_if_taint_is_undefined_or_no_op
+
       safe_test(unavailable: :skip) do
         result = @parser.parse('STD1DST,60,300'.dup.taint)
 
diff --git a/test/data_sources/tc_ruby_data_source.rb b/test/data_sources/tc_ruby_data_source.rb
index 1447bc76..88eb55d2 100644
--- a/test/data_sources/tc_ruby_data_source.rb
+++ b/test/data_sources/tc_ruby_data_source.rb
@@ -3,10 +3,6 @@
 
 require_relative '../test_utils'
 
-# Use send as a workaround for erroneous 'wrong number of arguments' errors with
-# JRuby 9.0.5.0 when calling methods with Java implementations. See #114.
-send(:using, TestUtils::TaintExt) if TestUtils.const_defined?(:TaintExt)
-
 module DataSources
   class TCRubyDataSource < Minitest::Test
     include TZInfo
@@ -123,6 +119,8 @@ def test_load_timezone_info_minus
     end
 
     def test_load_timezone_info_tainted
+      skip_if_taint_is_undefined_or_no_op
+
       safe_test(unavailable: :skip) do
         identifier = 'Europe/Amsterdam'.dup.taint
         assert(identifier.tainted?)
@@ -133,6 +131,8 @@ def test_load_timezone_info_tainted
     end
 
     def test_load_timezone_info_tainted_and_frozen
+      skip_if_taint_is_undefined_or_no_op
+
       safe_test do
         info = @data_source.send(:load_timezone_info, 'Europe/Amsterdam'.dup.taint.freeze)
         assert_equal('Europe/Amsterdam', info.identifier)
@@ -232,6 +232,8 @@ def test_load_country_info_case
     end
 
     def test_load_country_info_tainted
+      skip_if_taint_is_undefined_or_no_op
+
       safe_test(unavailable: :skip) do
         code = 'NL'.dup.taint
         assert(code.tainted?)
@@ -242,6 +244,8 @@ def test_load_country_info_tainted
     end
 
     def test_load_country_info_tainted_and_frozen
+      skip_if_taint_is_undefined_or_no_op
+
       safe_test do
         info = @data_source.send(:load_country_info, 'NL'.dup.taint.freeze)
         assert_equal('NL', info.code)
diff --git a/test/data_sources/tc_zoneinfo_data_source.rb b/test/data_sources/tc_zoneinfo_data_source.rb
index 5327d3bb..d812a174 100644
--- a/test/data_sources/tc_zoneinfo_data_source.rb
+++ b/test/data_sources/tc_zoneinfo_data_source.rb
@@ -6,17 +6,13 @@
 require 'pathname'
 require 'tmpdir'
 
-# Use send as a workaround for erroneous 'wrong number of arguments' errors with
-# JRuby 9.0.5.0 when calling methods with Java implementations. See #114.
-send(:using, TestUtils::TaintExt) if TestUtils.const_defined?(:TaintExt)
-send(:using, TZInfo.const_get(:UntaintExt)) if TZInfo.const_defined?(:UntaintExt)
-
 module DataSources
   class TCZoneinfoDataSource < Minitest::Test
     include TZInfo
     include TZInfo::DataSources
 
-    ZONEINFO_DIR = File.expand_path(File.join(File.dirname(__FILE__), '..', 'zoneinfo')).untaint
+    ZONEINFO_DIR = File.expand_path(File.join(File.dirname(__FILE__), '..', 'zoneinfo'))
+    RubyCoreSupport.untaint(ZONEINFO_DIR)
 
     def setup
       @orig_search_path = ZoneinfoDataSource.search_path.clone
@@ -788,6 +784,8 @@ def test_load_timezone_info_linked_relative_parent_inside
     end
 
     def test_load_timezone_info_tainted
+      skip_if_taint_is_undefined_or_no_op
+
       safe_test(unavailable: :skip) do
         identifier = 'Europe/Amsterdam'.dup.taint
         assert(identifier.tainted?)
@@ -798,6 +796,8 @@ def test_load_timezone_info_tainted
     end
 
     def test_load_timezone_info_tainted_and_frozen
+      skip_if_taint_is_undefined_or_no_op
+
       safe_test do
         info = @data_source.send(:load_timezone_info, 'Europe/Amsterdam'.dup.taint.freeze)
         assert_equal('Europe/Amsterdam', info.identifier)
@@ -805,6 +805,8 @@ def test_load_timezone_info_tainted_and_frozen
     end
 
     def test_load_timezone_info_tainted_zoneinfo_dir_safe_mode
+      skip_if_taint_is_undefined_or_no_op
+
       safe_test(unavailable: :skip) do
         assert_raises(SecurityError) do
           ZoneinfoDataSource.new(@data_source.zoneinfo_dir.dup.taint)
@@ -813,6 +815,7 @@ def test_load_timezone_info_tainted_zoneinfo_dir_safe_mode
     end
 
     def test_load_timezone_info_tainted_zoneinfo_dir
+      skip_if_taint_is_undefined_or_no_op
       data_source = ZoneinfoDataSource.new(@data_source.zoneinfo_dir.dup.taint)
       info = data_source.send(:load_timezone_info, 'Europe/London')
       assert_kind_of(TransitionsDataTimezoneInfo, info)
@@ -849,7 +852,7 @@ def get_timezone_filenames(directory)
       entries = Dir.glob(File.join(directory, '**', '*'))
 
       entries = entries.select do |file|
-        file.untaint
+        RubyCoreSupport.untaint(file)
         File.file?(file)
       end
 
@@ -1149,6 +1152,8 @@ def test_load_country_info_case
     end
 
     def test_load_country_info_tainted
+      skip_if_taint_is_undefined_or_no_op
+
       safe_test(unavailable: :skip) do
         code = 'NL'.dup.taint
         assert(code.tainted?)
diff --git a/test/data_sources/tc_zoneinfo_reader.rb b/test/data_sources/tc_zoneinfo_reader.rb
index 4a52228f..0d46cf5f 100644
--- a/test/data_sources/tc_zoneinfo_reader.rb
+++ b/test/data_sources/tc_zoneinfo_reader.rb
@@ -4,10 +4,6 @@
 require_relative '../test_utils'
 require 'tempfile'
 
-# Use send as a workaround for erroneous 'wrong number of arguments' errors with
-# JRuby 9.0.5.0 when calling methods with Java implementations. See #114.
-send(:using, TZInfo.const_get(:UntaintExt)) if TZInfo.const_defined?(:UntaintExt)
-
 module DataSources
   class TCZoneinfoReader < Minitest::Test
     include TZInfo
@@ -1257,7 +1253,7 @@ def test_read_untainted_in_safe_mode
       tzif_test(offsets, []) do |path, format|
         safe_test do
           # Temp file path is tainted with Ruby >= 2.3 & < 2.7. Untaint for this test.
-          path.untaint
+          RubyCoreSupport.untaint(path)
 
           assert_equal(o0, @reader.read(path))
         end
@@ -1265,6 +1261,8 @@ def test_read_untainted_in_safe_mode
     end
 
     def test_read_tainted_in_safe_mode
+      skip_if_taint_is_undefined_or_no_op
+
       offsets = [{gmtoff: -12094, isdst: false, abbrev: 'LT'}]
 
       tzif_test(offsets, []) do |path, format|
@@ -1278,6 +1276,8 @@ def test_read_tainted_in_safe_mode
     end
 
     def test_read_abbreviations_not_tainted
+      skip_if_taint_is_undefined_or_no_op
+
       offsets = [{gmtoff: -12094, isdst: false, abbrev: 'LT'}]
 
       tzif_test(offsets, []) do |path, format|
diff --git a/test/tc_country.rb b/test/tc_country.rb
index 02883f9e..3807b2ab 100644
--- a/test/tc_country.rb
+++ b/test/tc_country.rb
@@ -3,10 +3,6 @@
 
 require_relative 'test_utils'
 
-# Use send as a workaround for erroneous 'wrong number of arguments' errors with
-# JRuby 9.0.5.0 when calling methods with Java implementations. See #114.
-send(:using, TestUtils::TaintExt) if TestUtils.const_defined?(:TaintExt)
-
 class TCCountry < Minitest::Test
   include TZInfo
 
@@ -48,6 +44,7 @@ def test_get_nil
   end
 
   def test_get_tainted_loaded
+    skip_if_taint_is_undefined_or_no_op
     Country.get('GB')
 
     safe_test(unavailable: :skip) do
@@ -60,6 +57,7 @@ def test_get_tainted_loaded
   end
 
   def test_get_tainted_and_frozen_loaded
+    skip_if_taint_is_undefined_or_no_op
     Country.get('GB')
 
     safe_test do
@@ -69,6 +67,8 @@ def test_get_tainted_and_frozen_loaded
   end
 
   def test_get_tainted_not_previously_loaded
+    skip_if_taint_is_undefined_or_no_op
+
     safe_test(unavailable: :skip) do
       code = 'GB'.dup.taint
       assert(code.tainted?)
@@ -79,6 +79,8 @@ def test_get_tainted_not_previously_loaded
   end
 
   def test_get_tainted_and_frozen_not_previously_loaded
+    skip_if_taint_is_undefined_or_no_op
+
     safe_test do
       country = Country.get('GB'.dup.taint.freeze)
       assert_equal('GB', country.code)
diff --git a/test/tc_ruby_core_support.rb b/test/tc_ruby_core_support.rb
new file mode 100644
index 00000000..7253c0ea
--- /dev/null
+++ b/test/tc_ruby_core_support.rb
@@ -0,0 +1,19 @@
+# encoding: UTF-8
+# frozen_string_literal: true
+
+require_relative 'test_utils'
+
+class TCRubyCoreSupport < Minitest::Test
+  def test_untaint_returns_object
+    o = Object.new
+    assert_same(o, TZInfo.const_get(:RubyCoreSupport).untaint(o))
+  end
+
+  def test_untaint_untaints_object
+    skip_if_taint_is_undefined_or_no_op
+    o = Object.new.taint
+    assert(o.tainted?)
+    TZInfo.const_get(:RubyCoreSupport).untaint(o)
+    refute(o.tainted?)
+  end
+end
diff --git a/test/tc_timezone.rb b/test/tc_timezone.rb
index 0dc3300b..bd82af8b 100644
--- a/test/tc_timezone.rb
+++ b/test/tc_timezone.rb
@@ -3,10 +3,6 @@
 
 require_relative 'test_utils'
 
-# Use send as a workaround for erroneous 'wrong number of arguments' errors with
-# JRuby 9.0.5.0 when calling methods with Java implementations. See #114.
-send(:using, TestUtils::TaintExt) if TestUtils.const_defined?(:TaintExt)
-
 class TCTimezone < Minitest::Test
   include TZInfo
 
@@ -262,6 +258,7 @@ def test_get_nil
   end
 
   def test_get_tainted_loaded
+    skip_if_taint_is_undefined_or_no_op
     Timezone.get('Europe/Andorra')
 
     safe_test(unavailable: :skip) do
@@ -274,6 +271,7 @@ def test_get_tainted_loaded
   end
 
   def test_get_tainted_and_frozen_loaded
+    skip_if_taint_is_undefined_or_no_op
     Timezone.get('Europe/Andorra')
 
     safe_test do
@@ -283,6 +281,8 @@ def test_get_tainted_and_frozen_loaded
   end
 
   def test_get_tainted_not_previously_loaded
+    skip_if_taint_is_undefined_or_no_op
+
     safe_test(unavailable: :skip) do
       identifier = 'Europe/Andorra'.dup.taint
       assert(identifier.tainted?)
@@ -293,6 +293,8 @@ def test_get_tainted_not_previously_loaded
   end
 
   def test_get_tainted_and_frozen_not_previously_loaded
+    skip_if_taint_is_undefined_or_no_op
+
     safe_test do
       tz = Timezone.get('Europe/Amsterdam'.dup.taint.freeze)
       assert_equal('Europe/Amsterdam', tz.identifier)
diff --git a/test/test_utils.rb b/test/test_utils.rb
index ec83bf30..e23d7d24 100644
--- a/test/test_utils.rb
+++ b/test/test_utils.rb
@@ -28,7 +28,12 @@
     false
   end
 
-  feature_support = [['deduping_string_unary_minus', string_unary_minus_does_dedupe]].map do |feature, available|
+  untaint_is_functional = Object.new.respond_to?(:untaint) && RUBY_VERSION < '2.7'
+
+  feature_support = [
+    ['deduping_string_unary_minus', string_unary_minus_does_dedupe],
+    ['functional_untaint', untaint_is_functional]
+  ].map do |feature, available|
     "#{available ? '' : 'no_'}#{feature}"
   end
 
@@ -509,16 +514,23 @@ def assert_equal_with_offset_and_class(expected, actual)
       assert_equal_with_offset(expected, actual)
       assert_equal(expected.class, actual.class)
     end
-  end
 
-  # Object#taint is a deprecated no-op in Ruby 2.7 and outputs a warning. It
-  # will be removed in 3.2. Silence the warning or supply a replacement.
-  if TZInfo.const_defined?(:UntaintExt)
-    module TaintExt
-      refine Object do
-        def taint
-          self
+    # Object#taint is deprecated in Ruby >= 2.7 and will be removed in 3.2.
+    # 2.7 makes it a no-op with a warning.
+    # Define a method that will skip for use in tests that deal with tainted
+    # objects.
+    if Object.respond_to?(:taint)
+      if RUBY_VERSION >= '2.7'
+        def skip_if_taint_is_undefined_or_no_op
+          skip('Object#taint is a no-op')
         end
+      else
+        def skip_if_taint_is_undefined_or_no_op
+        end
+      end
+    else
+      def skip_if_taint_is_undefined_or_no_op
+        skip('Object#taint is not defined')
       end
     end
   end
diff --git a/test/ts_all_zoneinfo.rb b/test/ts_all_zoneinfo.rb
index 870a0618..d55bb286 100644
--- a/test/ts_all_zoneinfo.rb
+++ b/test/ts_all_zoneinfo.rb
@@ -8,7 +8,7 @@
 # Use a zoneinfo directory containing files needed by the tests.
 # The symlinks in this directory are set up in test_utils.rb.
 zoneinfo_path = File.join(File.expand_path(File.dirname(__FILE__)), 'zoneinfo')
-zoneinfo_path.untaint if RUBY_VERSION < '2.7'
+TZInfo::const_get(:RubyCoreSupport).untaint(zoneinfo_path)
 TZInfo::DataSource.set(:zoneinfo, zoneinfo_path)
 
 require_relative 'ts_all'