Update to ruby/spec@aaf998f

41 files changed, 820 insertions, 55 deletions

diff --git a/spec/ruby/.mspec.constants b/spec/ruby/.mspec.constants
index c070e35496..5dd477eb66 100644
--- a/spec/ruby/.mspec.constants
+++ b/spec/ruby/.mspec.constants
@@ -39,6 +39,8 @@ CodingUS_ASCII
 CodingUTF_8
 ComparisonTest
 ConstantSpecsIncludedModule
+ConstantSpecsTwo
+ConstantSpecsThree
 ConstantVisibility
 Coverage
 CoverageSpecs
diff --git a/spec/ruby/README.md b/spec/ruby/README.md
index e62ddc7dce..df98723c9b 100644
--- a/spec/ruby/README.md
+++ b/spec/ruby/README.md
@@ -18,13 +18,13 @@ Every example code has a textual description, which presents several advantages:
 
 The specs are written with syntax similar to RSpec 2.
 They are run with MSpec, the purpose-built framework for running the Ruby Spec Suite.
-For more information, see the [MSpec](http://github.com/ruby/mspec) project.
+For more information, see the [MSpec](https://github.com/ruby/mspec) project.
 
 The specs describe the [language syntax](language/), the [core library](core/), the [standard library](library/), the [C API for extensions](optional/capi) and the [command line flags](command_line/).
 The language specs are grouped by keyword while the core and standard library specs are grouped by class and method.
 
 ruby/spec is known to be tested in these implementations for every commit:
-* [MRI](http://rubyci.org/) on 30 platforms and 4 versions
+* [MRI](https://rubyci.org/) on 30 platforms and 4 versions
 * [JRuby](https://github.com/jruby/jruby/tree/master/spec/ruby) for both 1.7 and 9.x
 * [TruffleRuby](https://github.com/oracle/truffleruby/tree/master/spec/ruby)
 * [Opal](https://github.com/opal/opal/tree/master/spec)
@@ -70,7 +70,7 @@ Then move to it:
 
     $ cd spec
 
-Clone [MSpec](http://github.com/ruby/mspec):
+Clone [MSpec](https://github.com/ruby/mspec):
 
     $ git clone https://github.com/ruby/mspec.git ../mspec
 
@@ -152,5 +152,5 @@ This project was originally born from [Rubinius](https://github.com/rubinius/rub
 The revision history of these specs is available [here](https://github.com/ruby/spec/blob/2b886623/CHANGES.before-2008-05-10).
 These specs were later extracted to their own project, RubySpec, with a specific vision and principles.
 At the end of 2014, Brian Shirai, the creator of RubySpec, decided to [end RubySpec](http://rubinius.com/2014/12/31/matz-s-ruby-developers-don-t-use-rubyspec/).
-A couple months later, the different repositories were merged and [the project was revived](http://eregon.github.io/rubyspec/2015/07/29/rubyspec-is-reborn.html).
+A couple months later, the different repositories were merged and [the project was revived](https://eregon.github.io/rubyspec/2015/07/29/rubyspec-is-reborn.html).
 On 12 January 2016, the name was changed to "The Ruby Spec Suite" for clarity and to let the RubySpec ideology rest in peace.
diff --git a/spec/ruby/core/array/pack/x_spec.rb b/spec/ruby/core/array/pack/x_spec.rb
index a28dd0bf21..86c3ad1aa4 100644
--- a/spec/ruby/core/array/pack/x_spec.rb
+++ b/spec/ruby/core/array/pack/x_spec.rb
@@ -30,6 +30,7 @@ describe "Array#pack with format 'x'" do
 
   it "does not add a NULL byte when passed the '*' modifier" do
     [].pack("x*").should == ""
+    [1, 2].pack("Cx*C").should == "\x01\x02"
   end
 end
 
diff --git a/spec/ruby/core/array/sample_spec.rb b/spec/ruby/core/array/sample_spec.rb
index 565d7ff7f9..755b46f126 100644
--- a/spec/ruby/core/array/sample_spec.rb
+++ b/spec/ruby/core/array/sample_spec.rb
@@ -19,10 +19,18 @@ describe "Array#sample" do
     [].sample.should be_nil
   end
 
+  it "returns nil for an empty array when called without n and a Random is given" do
+    [].sample(random: Random.new(42)).should be_nil
+  end
+
   it "returns a single value when not passed a count" do
     [4].sample.should equal(4)
   end
 
+  it "returns a single value when not passed a count and a Random is given" do
+    [4].sample(random: Random.new(42)).should equal(4)
+  end
+
   it "returns an empty Array when passed zero" do
     [4].sample(0).should == []
   end
diff --git a/spec/ruby/core/dir/foreach_spec.rb b/spec/ruby/core/dir/foreach_spec.rb
index c3ddb27a84..85e8c61fd6 100644
--- a/spec/ruby/core/dir/foreach_spec.rb
+++ b/spec/ruby/core/dir/foreach_spec.rb
@@ -42,6 +42,13 @@ describe "Dir.foreach" do
   it "accepts an encoding keyword for the encoding of the entries" do
     dirs = Dir.foreach("#{DirSpecs.mock_dir}/deeply/nested", encoding: "utf-8").to_a.sort
     dirs.each {|dir| dir.encoding.should == Encoding::UTF_8}
+
+    dirs = Dir.foreach("#{DirSpecs.mock_dir}/deeply/nested", encoding: Encoding::UTF_16LE).to_a.sort
+    dirs.each {|dir| dir.encoding.should == Encoding::UTF_16LE}
+
+    Dir.foreach("#{DirSpecs.mock_dir}/deeply/nested", encoding: Encoding::UTF_16LE) do |f|
+      f.encoding.should == Encoding::UTF_16LE
+    end
   end
 
   ruby_version_is ""..."2.7" do
diff --git a/spec/ruby/core/enumerable/shared/inject.rb b/spec/ruby/core/enumerable/shared/inject.rb
index 12e0665dda..e59b82b02e 100644
--- a/spec/ruby/core/enumerable/shared/inject.rb
+++ b/spec/ruby/core/enumerable/shared/inject.rb
@@ -66,4 +66,11 @@ describe :enumerable_inject, shared: true do
   it "returns nil when fails(legacy rubycon)" do
     EnumerableSpecs::EachDefiner.new().send(@method) {|acc,x| 999 }.should == nil
   end
+
+  ruby_bug '#18635', ''...'3.2' do
+    it "raises an ArgumentError when no parameters or block is given" do
+      -> { [1,2].send(@method) }.should raise_error(ArgumentError)
+      -> { {one: 1, two: 2}.send(@method) }.should raise_error(ArgumentError)
+    end
+  end
 end
diff --git a/spec/ruby/core/enumerator/lazy/with_index_spec.rb b/spec/ruby/core/enumerator/lazy/with_index_spec.rb
index 3a59ba4116..b6dbe554d9 100644
--- a/spec/ruby/core/enumerator/lazy/with_index_spec.rb
+++ b/spec/ruby/core/enumerator/lazy/with_index_spec.rb
@@ -26,5 +26,13 @@ ruby_version_is "2.7" do
       (0..Float::INFINITY).lazy.with_index { |i, idx| result << [i * 2, idx] }.first(3)
       result.should == [[0,0],[2,1],[4,2]]
     end
+
+    it "resets after a new call to each" do
+      enum = (0..2).lazy.with_index.map { |i, idx| [i, idx] }
+      result = []
+      enum.each { |i, idx| result << [i, idx] }
+      enum.each { |i, idx| result << [i, idx] }
+      result.should == [[0,0], [1,1], [2,2], [0,0], [1,1], [2,2]]
+    end
   end
 end
diff --git a/spec/ruby/core/exception/full_message_spec.rb b/spec/ruby/core/exception/full_message_spec.rb
index 4cece9ebf9..9757a2f407 100644
--- a/spec/ruby/core/exception/full_message_spec.rb
+++ b/spec/ruby/core/exception/full_message_spec.rb
@@ -15,13 +15,19 @@ describe "Exception#full_message" do
   it "supports :highlight option and adds escape sequences to highlight some strings" do
     e = RuntimeError.new("Some runtime error")
 
-    full_message = e.full_message(highlight: true, order: :bottom)
-    full_message.should include "\e[1mTraceback\e[m (most recent call last)"
-    full_message.should include "\e[1mSome runtime error (\e[1;4mRuntimeError\e[m\e[1m)"
+    full_message = e.full_message(highlight: true, order: :top).lines
+    full_message[0].should.end_with? "\e[1mSome runtime error (\e[1;4mRuntimeError\e[m\e[1m)\e[m\n"
 
-    full_message = e.full_message(highlight: false, order: :bottom)
-    full_message.should include "Traceback (most recent call last)"
-    full_message.should include "Some runtime error (RuntimeError)"
+    full_message = e.full_message(highlight: true, order: :bottom).lines
+    full_message[0].should == "\e[1mTraceback\e[m (most recent call last):\n"
+    full_message[-1].should.end_with? "\e[1mSome runtime error (\e[1;4mRuntimeError\e[m\e[1m)\e[m\n"
+
+    full_message = e.full_message(highlight: false, order: :top).lines
+    full_message[0].should.end_with? "Some runtime error (RuntimeError)\n"
+
+    full_message = e.full_message(highlight: false, order: :bottom).lines
+    full_message[0].should == "Traceback (most recent call last):\n"
+    full_message[-1].should.end_with? "Some runtime error (RuntimeError)\n"
   end
 
   it "supports :order option and places the error message and the backtrace at the top or the bottom" do
@@ -35,9 +41,9 @@ describe "Exception#full_message" do
   it "shows the caller if the exception has no backtrace" do
     e = RuntimeError.new("Some runtime error")
     e.backtrace.should == nil
-    full_message = e.full_message(highlight: false, order: :top)
-    full_message.should include("#{__FILE__}:#{__LINE__-1}:in `")
-    full_message.should include("': Some runtime error (RuntimeError)\n")
+    full_message = e.full_message(highlight: false, order: :top).lines
+    full_message[0].should.start_with?("#{__FILE__}:#{__LINE__-1}:in `")
+    full_message[0].should.end_with?("': Some runtime error (RuntimeError)\n")
   end
 
   it "shows the exception class at the end of the first line of the message when the message contains multiple lines" do
@@ -45,12 +51,24 @@ describe "Exception#full_message" do
       line = __LINE__; raise "first line\nsecond line"
     rescue => e
       full_message = e.full_message(highlight: false, order: :top).lines
-      full_message[0].should include("#{__FILE__}:#{line}:in `")
-      full_message[0].should include(": first line (RuntimeError)\n")
+      full_message[0].should.start_with?("#{__FILE__}:#{line}:in `")
+      full_message[0].should.end_with?(": first line (RuntimeError)\n")
       full_message[1].should == "second line\n"
     end
   end
 
+  it "highlights the entire message when the message contains multiple lines" do
+    begin
+      line = __LINE__; raise "first line\nsecond line\nthird line"
+    rescue => e
+      full_message = e.full_message(highlight: true, order: :top).lines
+      full_message[0].should.start_with?("#{__FILE__}:#{line}:in `")
+      full_message[0].should.end_with?(": \e[1mfirst line (\e[1;4mRuntimeError\e[m\e[1m)\e[m\n")
+      full_message[1].should == "\e[1msecond line\e[m\n"
+      full_message[2].should == "\e[1mthird line\e[m\n"
+    end
+  end
+
   it "contains cause of exception" do
     begin
       begin
diff --git a/spec/ruby/core/exception/system_exit_spec.rb b/spec/ruby/core/exception/system_exit_spec.rb
index eef9faf271..d899844c4e 100644
--- a/spec/ruby/core/exception/system_exit_spec.rb
+++ b/spec/ruby/core/exception/system_exit_spec.rb
@@ -1,6 +1,48 @@
 require_relative '../../spec_helper'
 
 describe "SystemExit" do
+  describe "#initialize" do
+    it "accepts a status and message" do
+      exc = SystemExit.new(42, "message")
+      exc.status.should == 42
+      exc.message.should == "message"
+
+      exc = SystemExit.new(true, "message")
+      exc.status.should == 0
+      exc.message.should == "message"
+
+      exc = SystemExit.new(false, "message")
+      exc.status.should == 1
+      exc.message.should == "message"
+    end
+
+    it "accepts a status only" do
+      exc = SystemExit.new(42)
+      exc.status.should == 42
+      exc.message.should == "SystemExit"
+
+      exc = SystemExit.new(true)
+      exc.status.should == 0
+      exc.message.should == "SystemExit"
+
+      exc = SystemExit.new(false)
+      exc.status.should == 1
+      exc.message.should == "SystemExit"
+    end
+
+    it "accepts a message only" do
+      exc = SystemExit.new("message")
+      exc.status.should == 0
+      exc.message.should == "message"
+    end
+
+    it "accepts no arguments" do
+      exc = SystemExit.new
+      exc.status.should == 0
+      exc.message.should == "SystemExit"
+    end
+  end
+
   it "sets the exit status and exits silently when raised" do
     code = 'raise SystemExit.new(7)'
     result = ruby_exe(code, args: "2>&1", exit_status: 7)
diff --git a/spec/ruby/core/file/utime_spec.rb b/spec/ruby/core/file/utime_spec.rb
index 59eef20c66..a191e29240 100644
--- a/spec/ruby/core/file/utime_spec.rb
+++ b/spec/ruby/core/file/utime_spec.rb
@@ -77,6 +77,10 @@ describe "File.utime" do
     File.mtime(@file1).nsec.should.between?(0, 123500000)
   end
 
+  it "returns the number of filenames in the arguments" do
+    File.utime(@atime.to_f, @mtime.to_f, @file1, @file2).should == 2
+  end
+
   platform_is :linux do
     platform_is wordsize: 64 do
       it "allows Time instances in the far future to set mtime and atime (but some filesystems limit it up to 2446-05-10 or 2038-01-19)" do
diff --git a/spec/ruby/core/hash/ruby2_keywords_hash_spec.rb b/spec/ruby/core/hash/ruby2_keywords_hash_spec.rb
index 005886a482..13e8ffe4af 100644
--- a/spec/ruby/core/hash/ruby2_keywords_hash_spec.rb
+++ b/spec/ruby/core/hash/ruby2_keywords_hash_spec.rb
@@ -40,6 +40,20 @@ ruby_version_is "2.7" do
       kw.should == h
     end
 
+    it "copies instance variables" do
+      h = {a: 1}
+      h.instance_variable_set(:@foo, 42)
+      kw = Hash.ruby2_keywords_hash(h)
+      kw.instance_variable_get(:@foo).should == 42
+    end
+
+    it "copies the hash internals" do
+      h = {a: 1}
+      kw = Hash.ruby2_keywords_hash(h)
+      h[:a] = 2
+      kw[:a].should == 1
+    end
+
     it "raises TypeError for non-Hash" do
       -> { Hash.ruby2_keywords_hash(nil) }.should raise_error(TypeError)
     end
diff --git a/spec/ruby/core/hash/shared/to_s.rb b/spec/ruby/core/hash/shared/to_s.rb
index b0e3705d01..c74537aed4 100644
--- a/spec/ruby/core/hash/shared/to_s.rb
+++ b/spec/ruby/core/hash/shared/to_s.rb
@@ -2,7 +2,6 @@ require_relative '../../../spec_helper'
 require_relative '../fixtures/classes'
 
 describe :hash_to_s, shared: true do
-
   it "returns a string representation with same order as each()" do
     h = { a: [1, 2], b: -2, d: -6, nil => nil }
 
@@ -95,4 +94,8 @@ describe :hash_to_s, shared: true do
 
     {a: utf_16be}.send(@method).should == '{:a=>"utf_16be \u3042"}'
   end
+
+  it "works for keys and values whose #inspect return a frozen String" do
+    { true => false }.to_s.should == "{true=>false}"
+  end
 end
diff --git a/spec/ruby/core/io/shared/readlines.rb b/spec/ruby/core/io/shared/readlines.rb
index 8e4a73bb98..52b20364ef 100644
--- a/spec/ruby/core/io/shared/readlines.rb
+++ b/spec/ruby/core/io/shared/readlines.rb
@@ -73,6 +73,11 @@ describe :io_readlines_options_19, shared: true do
         result = IO.send(@method, @name, 10, &@object)
         (result ? result : ScratchPad.recorded).should == IOSpecs.lines_limit
       end
+
+      it "ignores the object as a limit if it is negative" do
+        result = IO.send(@method, @name, -2, &@object)
+        (result ? result : ScratchPad.recorded).should == IOSpecs.lines
+      end
     end
 
     describe "when the object is a String" do
diff --git a/spec/ruby/core/kernel/define_singleton_method_spec.rb b/spec/ruby/core/kernel/define_singleton_method_spec.rb
index dc77c3e6f8..2d8b1bf413 100644
--- a/spec/ruby/core/kernel/define_singleton_method_spec.rb
+++ b/spec/ruby/core/kernel/define_singleton_method_spec.rb
@@ -96,4 +96,19 @@ describe "Kernel#define_singleton_method" do
       o.define(:foo) { raise "not used" }
     }.should raise_error(ArgumentError)
   end
+
+  it "always defines the method with public visibility" do
+    cls = Class.new
+    def cls.define(name, &block)
+      private
+      define_singleton_method(name, &block)
+    end
+
+    -> {
+      suppress_warning do
+        cls.define(:foo) { :ok }
+      end
+      cls.foo.should == :ok
+    }.should_not raise_error(NoMethodError)
+  end
 end
diff --git a/spec/ruby/core/math/sqrt_spec.rb b/spec/ruby/core/math/sqrt_spec.rb
index 779aea2a0a..918e7c3a17 100644
--- a/spec/ruby/core/math/sqrt_spec.rb
+++ b/spec/ruby/core/math/sqrt_spec.rb
@@ -27,6 +27,10 @@ describe "Math.sqrt" do
   it "accepts any argument that can be coerced with Float()" do
     Math.sqrt(MathSpecs::Float.new).should be_close(1.0, TOLERANCE)
   end
+
+  it "raises a Math::DomainError when given a negative number" do
+    -> { Math.sqrt(-1) }.should raise_error(Math::DomainError)
+  end
 end
 
 describe "Math#sqrt" do
diff --git a/spec/ruby/core/module/const_get_spec.rb b/spec/ruby/core/module/const_get_spec.rb
index 9f9fafe5bb..69f181cf51 100644
--- a/spec/ruby/core/module/const_get_spec.rb
+++ b/spec/ruby/core/module/const_get_spec.rb
@@ -100,6 +100,16 @@ describe "Module#const_get" do
     ConstantSpecs.const_get("::CS_CONST1").should == :const1
   end
 
+  it "accepts a toplevel scope qualifier when inherit is false" do
+    ConstantSpecs.const_get("::CS_CONST1", false).should == :const1
+    -> { ConstantSpecs.const_get("CS_CONST1", false) }.should raise_error(NameError)
+  end
+
+  it "returns a constant whose module is defined the the toplevel" do
+    ConstantSpecs.const_get("ConstantSpecsTwo::Foo").should == :cs_two_foo
+    ConstantSpecsThree.const_get("ConstantSpecsTwo::Foo").should == :cs_three_foo
+  end
+
   it "accepts a scoped constant name" do
     ConstantSpecs.const_get("ClassA::CS_CONST10").should == :const10_10
   end
@@ -140,6 +150,10 @@ describe "Module#const_get" do
     Object.const_get('CSAutoloadD::InnerModule').name.should == 'CSAutoloadD::InnerModule'
   end
 
+  it "raises a NameError when the nested constant does not exist on the module but exists in Object" do
+    -> { Object.const_get('ConstantSpecs::CS_CONST1') }.should raise_error(NameError)
+  end
+
   describe "with statically assigned constants" do
     it "searches the immediate class or module first" do
       ConstantSpecs::ClassA.const_get(:CS_CONST10).should == :const10_10
diff --git a/spec/ruby/core/module/ruby2_keywords_spec.rb b/spec/ruby/core/module/ruby2_keywords_spec.rb
index 996774891c..6de3fdec80 100644
--- a/spec/ruby/core/module/ruby2_keywords_spec.rb
+++ b/spec/ruby/core/module/ruby2_keywords_spec.rb
@@ -15,6 +15,83 @@ ruby_version_is "2.7" do
       Hash.ruby2_keywords_hash?(last).should == true
     end
 
+    it "makes a copy of the hash and only marks the copy as keyword hash" do
+      obj = Object.new
+      obj.singleton_class.class_exec do
+        def regular(*args)
+          args.last
+        end
+
+        ruby2_keywords def foo(*args)
+          args.last
+        end
+      end
+
+      h = {a: 1}
+      ruby_version_is "3.0" do
+        obj.regular(**h).should.equal?(h)
+      end
+
+      last = obj.foo(**h)
+      Hash.ruby2_keywords_hash?(last).should == true
+      Hash.ruby2_keywords_hash?(h).should == false
+
+      last2 = obj.foo(**last) # last is already marked
+      Hash.ruby2_keywords_hash?(last2).should == true
+      Hash.ruby2_keywords_hash?(last).should == true
+      last2.should_not.equal?(last)
+      Hash.ruby2_keywords_hash?(h).should == false
+    end
+
+    it "makes a copy and unmark at the call site when calling with marked *args" do
+      obj = Object.new
+      obj.singleton_class.class_exec do
+        ruby2_keywords def foo(*args)
+          args
+        end
+
+        def single(arg)
+          arg
+        end
+
+        def splat(*args)
+          args.last
+        end
+
+        def kwargs(**kw)
+          kw
+        end
+      end
+
+      h = { a: 1 }
+      args = obj.foo(**h)
+      marked = args.last
+      Hash.ruby2_keywords_hash?(marked).should == true
+
+      after_usage = obj.single(*args)
+      after_usage.should == h
+      after_usage.should_not.equal?(h)
+      after_usage.should_not.equal?(marked)
+      Hash.ruby2_keywords_hash?(after_usage).should == false
+      Hash.ruby2_keywords_hash?(marked).should == true
+
+      after_usage = obj.splat(*args)
+      after_usage.should == h
+      after_usage.should_not.equal?(h)
+      after_usage.should_not.equal?(marked)
+      ruby_bug "#18625", ""..."3.3" do # might be fixed in 3.2
+        Hash.ruby2_keywords_hash?(after_usage).should == false
+      end
+      Hash.ruby2_keywords_hash?(marked).should == true
+
+      after_usage = obj.kwargs(*args)
+      after_usage.should == h
+      after_usage.should_not.equal?(h)
+      after_usage.should_not.equal?(marked)
+      Hash.ruby2_keywords_hash?(after_usage).should == false
+      Hash.ruby2_keywords_hash?(marked).should == true
+    end
+
     it "applies to the underlying method and applies across aliasing" do
       obj = Object.new
 
@@ -80,7 +157,7 @@ ruby_version_is "2.7" do
       }.should raise_error(NameError, /undefined method `not_existing'/)
     end
 
-    it "acceps String as well" do
+    it "accepts String as well" do
       obj = Object.new
 
       obj.singleton_class.class_exec do
diff --git a/spec/ruby/core/proc/parameters_spec.rb b/spec/ruby/core/proc/parameters_spec.rb
index 3ced7b22ab..3a56b613cd 100644
--- a/spec/ruby/core/proc/parameters_spec.rb
+++ b/spec/ruby/core/proc/parameters_spec.rb
@@ -31,7 +31,7 @@ describe "Proc#parameters" do
     end
 
     it "regards named parameters in lambda as optional if lambda: false keyword used" do
-      lambda {|x| }.parameters(lambda: false).first.first.should == :opt
+      -> x { }.parameters(lambda: false).first.first.should == :opt
     end
   end
 
diff --git a/spec/ruby/core/random/rand_spec.rb b/spec/ruby/core/random/rand_spec.rb
index 6ea7eece5f..9244177ab5 100644
--- a/spec/ruby/core/random/rand_spec.rb
+++ b/spec/ruby/core/random/rand_spec.rb
@@ -205,6 +205,11 @@ describe "Random#rand with Range" do
     Random.new(42).rand(0..1.0).should be_kind_of(Float)
   end
 
+  it "returns a float within a given float range" do
+    Random.new(42).rand(0.0...100.0).should == 37.454011884736246
+    Random.new(42).rand(-100.0...0.0).should == -62.545988115263754
+  end
+
   it "raises an ArgumentError when the startpoint lacks #+ and #- methods" do
     -> do
       Random.new.rand(Object.new..67)
diff --git a/spec/ruby/core/string/append_spec.rb b/spec/ruby/core/string/append_spec.rb
index 1e1667f617..e001257621 100644
--- a/spec/ruby/core/string/append_spec.rb
+++ b/spec/ruby/core/string/append_spec.rb
@@ -5,4 +5,9 @@ require_relative 'shared/concat'
 describe "String#<<" do
   it_behaves_like :string_concat, :<<
   it_behaves_like :string_concat_encoding, :<<
+
+  it "raises an ArgumentError when given the incorrect number of arguments" do
+    -> { "hello".send(:<<) }.should raise_error(ArgumentError)
+    -> { "hello".send(:<<, "one", "two") }.should raise_error(ArgumentError)
+  end
 end
diff --git a/spec/ruby/core/string/comparison_spec.rb b/spec/ruby/core/string/comparison_spec.rb
index 01199274b6..91cfdca25a 100644
--- a/spec/ruby/core/string/comparison_spec.rb
+++ b/spec/ruby/core/string/comparison_spec.rb
@@ -75,6 +75,10 @@ describe "String#<=> with String" do
     (xff_1 <=> xff_2).should == -1
     (xff_2 <=> xff_1).should ==  1
   end
+
+  it "returns 0 when comparing 2 empty strings but one is not ASCII-compatible" do
+    ("" <=> "".force_encoding('iso-2022-jp')).should == 0
+  end
 end
 
 # Note: This is inconsistent with Array#<=> which calls #to_ary instead of
diff --git a/spec/ruby/core/string/lstrip_spec.rb b/spec/ruby/core/string/lstrip_spec.rb
index 20e4cdeabd..8b5dd1b467 100644
--- a/spec/ruby/core/string/lstrip_spec.rb
+++ b/spec/ruby/core/string/lstrip_spec.rb
@@ -12,7 +12,7 @@ describe "String#lstrip" do
    "hello".lstrip.should == "hello"
   end
 
-  ruby_version_is '3.1' do
+  ruby_version_is '3.0' do
     it "strips leading \\0" do
      "\x00hello".lstrip.should == "hello"
      "\000 \000hello\000 \000".lstrip.should == "hello\000 \000"
@@ -35,7 +35,7 @@ describe "String#lstrip!" do
     a.should == "hello  "
   end
 
-  ruby_version_is '3.1' do
+  ruby_version_is '3.0' do
     it "strips leading \\0" do
       a = "\000 \000hello\000 \000"
       a.lstrip!
diff --git a/spec/ruby/core/string/rindex_spec.rb b/spec/ruby/core/string/rindex_spec.rb
index 7a6af0c9d0..a3b437a1e4 100644
--- a/spec/ruby/core/string/rindex_spec.rb
+++ b/spec/ruby/core/string/rindex_spec.rb
@@ -4,13 +4,17 @@ require_relative 'fixtures/classes'
 require_relative 'fixtures/utf-8-encoding'
 
 describe "String#rindex with object" do
-  it "raises a TypeError if obj isn't a String, Integer or Regexp" do
+  it "raises a TypeError if obj isn't a String or Regexp" do
     not_supported_on :opal do
       -> { "hello".rindex(:sym) }.should raise_error(TypeError)
     end
     -> { "hello".rindex(mock('x')) }.should raise_error(TypeError)
   end
 
+  it "raises a TypeError if obj is an Integer" do
+    -> { "hello".rindex(42) }.should raise_error(TypeError)
+  end
+
   it "doesn't try to convert obj to an integer via to_int" do
     obj = mock('x')
     obj.should_not_receive(:to_int)
diff --git a/spec/ruby/core/string/shared/eql.rb b/spec/ruby/core/string/shared/eql.rb
index b57d6895ff..6f268c929c 100644
--- a/spec/ruby/core/string/shared/eql.rb
+++ b/spec/ruby/core/string/shared/eql.rb
@@ -31,4 +31,8 @@ describe :string_eql_value, shared: true do
     a.send(@method, b).should be_true
     b.send(@method, a).should be_true
   end
+
+  it "returns true when comparing 2 empty strings but one is not ASCII-compatible" do
+    "".send(@method, "".force_encoding('iso-2022-jp')).should == true
+  end
 end
diff --git a/spec/ruby/core/string/split_spec.rb b/spec/ruby/core/string/split_spec.rb
index 2e03955a26..2da71948b3 100644
--- a/spec/ruby/core/string/split_spec.rb
+++ b/spec/ruby/core/string/split_spec.rb
@@ -589,4 +589,11 @@ describe "String#split with Regexp" do
       end
     end
   end
+
+  it "raises a TypeError when not called with nil, String, or Regexp" do
+    -> { "hello".split(42) }.should raise_error(TypeError)
+    -> { "hello".split(:ll) }.should raise_error(TypeError)
+    -> { "hello".split(false) }.should raise_error(TypeError)
+    -> { "hello".split(Object.new) }.should raise_error(TypeError)
+  end
 end
diff --git a/spec/ruby/core/string/strip_spec.rb b/spec/ruby/core/string/strip_spec.rb
index 8517bf2d2a..da06862d06 100644
--- a/spec/ruby/core/string/strip_spec.rb
+++ b/spec/ruby/core/string/strip_spec.rb
@@ -11,7 +11,7 @@ describe "String#strip" do
     "\tgoodbye\r\v\n".strip.should == "goodbye"
   end
 
-  ruby_version_is '3.1' do
+  ruby_version_is '3.0' do
     it "returns a copy of self without leading and trailing NULL bytes and whitespace" do
       " \x00 goodbye \x00 ".strip.should == "goodbye"
     end
@@ -43,7 +43,7 @@ describe "String#strip!" do
     a.should == "hello"
   end
 
-  ruby_version_is '3.1' do
+  ruby_version_is '3.0' do
     it "removes leading and trailing NULL bytes and whitespace" do
       a = "\000 goodbye \000"
       a.strip!
diff --git a/spec/ruby/core/struct/new_spec.rb b/spec/ruby/core/struct/new_spec.rb
index fdbf8c2c91..7b4a4f7980 100644
--- a/spec/ruby/core/struct/new_spec.rb
+++ b/spec/ruby/core/struct/new_spec.rb
@@ -60,14 +60,21 @@ describe "Struct.new" do
     -> { Struct.new(:animal, nil)                  }.should raise_error(TypeError)
     -> { Struct.new(:animal, true)                 }.should raise_error(TypeError)
     -> { Struct.new(:animal, ['chris', 'evan'])    }.should raise_error(TypeError)
-    ruby_version_is "3.2" do
-      -> { Struct.new(:animal, { name: 'chris' }) }.should raise_error(TypeError)
-    end
   end
 
   ruby_version_is ""..."3.2" do
-    it "raises a ArgumentError if passed a Hash with an unknown key" do
-      -> { Struct.new(:animal, { name: 'chris' }) }.should raise_error(ArgumentError)
+    it "raises a TypeError or ArgumentError if passed a Hash with an unknown key" do
+      # CRuby < 3.2 raises ArgumentError: unknown keyword: :name, but that seems a bug:
+      # https://bugs.ruby-lang.org/issues/18632
+      -> { Struct.new(:animal, { name: 'chris' }) }.should raise_error(StandardError) { |e|
+        [ArgumentError, TypeError].should.include?(e.class)
+      }
+    end
+  end
+
+  ruby_version_is "3.2" do
+    it "raises a TypeError if passed a Hash with an unknown key" do
+      -> { Struct.new(:animal, { name: 'chris' }) }.should raise_error(TypeError)
     end
   end
 
diff --git a/spec/ruby/core/thread/shared/exit.rb b/spec/ruby/core/thread/shared/exit.rb
index 40dc478947..3663827579 100644
--- a/spec/ruby/core/thread/shared/exit.rb
+++ b/spec/ruby/core/thread/shared/exit.rb
@@ -66,6 +66,26 @@ describe :thread_exit, shared: true do
     ScratchPad.recorded.should == nil
   end
 
+  it "does not reset $!" do
+    ScratchPad.record []
+
+    exc = RuntimeError.new("foo")
+    thread = Thread.new do
+      begin
+        raise exc
+      ensure
+        ScratchPad << $!
+        begin
+          Thread.current.send(@method)
+        ensure
+          ScratchPad << $!
+        end
+      end
+    end
+    thread.join
+    ScratchPad.recorded.should == [exc, exc]
+  end
+
   it "cannot be rescued" do
     thread = Thread.new do
       begin
@@ -73,7 +93,7 @@ describe :thread_exit, shared: true do
       rescue Exception
         ScratchPad.record :in_rescue
       end
-     ScratchPad.record :end_of_thread_block
+      ScratchPad.record :end_of_thread_block
     end
 
     thread.join
diff --git a/spec/ruby/fixtures/constants.rb b/spec/ruby/fixtures/constants.rb
index 37271ddcc8..4c456dae89 100644
--- a/spec/ruby/fixtures/constants.rb
+++ b/spec/ruby/fixtures/constants.rb
@@ -299,4 +299,14 @@ module ConstantSpecs
   private_constant :CS_PRIVATE
 end
 
+module ConstantSpecsThree
+  module ConstantSpecsTwo
+    Foo = :cs_three_foo
+  end
+end
+
+module ConstantSpecsTwo
+  Foo = :cs_two_foo
+end
+
 include ConstantSpecs::ModuleA
diff --git a/spec/ruby/language/keyword_arguments_spec.rb b/spec/ruby/language/keyword_arguments_spec.rb
new file mode 100644
index 0000000000..66e37915a2
--- /dev/null
+++ b/spec/ruby/language/keyword_arguments_spec.rb
@@ -0,0 +1,307 @@
+require_relative '../spec_helper'
+
+ruby_version_is "3.0" do
+  describe "Keyword arguments" do
+    def target(*args, **kwargs)
+      [args, kwargs]
+    end
+
+    it "are separated from positional arguments" do
+      def m(*args, **kwargs)
+        [args, kwargs]
+      end
+
+      empty = {}
+      m(**empty).should == [[], {}]
+      m(empty).should == [[{}], {}]
+
+      m(a: 1).should == [[], {a: 1}]
+      m({a: 1}).should == [[{a: 1}], {}]
+    end
+
+    it "when the receiving method has not keyword parameters it treats kwargs as positional" do
+      def m(*a)
+        a
+      end
+
+      m(a: 1).should == [{a: 1}]
+      m({a: 1}).should == [{a: 1}]
+    end
+
+    context "empty kwargs are treated as if they were not passed" do
+      it "when calling a method" do
+        def m(*a)
+          a
+        end
+
+        empty = {}
+        m(**empty).should == []
+        m(empty).should == [{}]
+      end
+
+      it "when yielding to a block" do
+        def y(*args, **kwargs)
+          yield(*args, **kwargs)
+        end
+
+        empty = {}
+        y(**empty) { |*a| a }.should == []
+        y(empty) { |*a| a }.should == [{}]
+      end
+    end
+
+    it "extra keywords are not allowed without **kwrest" do
+      def m(*a, kw:)
+        a
+      end
+
+      m(kw: 1).should == []
+      -> { m(kw: 1, kw2: 2) }.should raise_error(ArgumentError, 'unknown keyword: :kw2')
+      -> { m(kw: 1, true => false) }.should raise_error(ArgumentError, 'unknown keyword: true')
+    end
+
+    it "handle * and ** at the same call site" do
+      def m(*a)
+        a
+      end
+
+      m(*[], **{}).should == []
+      m(*[], 42, **{}).should == [42]
+    end
+
+    context "**" do
+      it "does not copy a non-empty Hash for a method taking (*args)" do
+        def m(*args)
+          args[0]
+        end
+
+        h = {a: 1}
+        m(**h).should.equal?(h)
+      end
+
+      it "copies the given Hash for a method taking (**kwargs)" do
+        def m(**kw)
+          kw
+        end
+
+        empty = {}
+        m(**empty).should == empty
+        m(**empty).should_not.equal?(empty)
+
+        h = {a: 1}
+        m(**h).should == h
+        m(**h).should_not.equal?(h)
+      end
+    end
+
+    context "delegation" do
+      it "works with (*args, **kwargs)" do
+        def m(*args, **kwargs)
+          target(*args, **kwargs)
+        end
+
+        empty = {}
+        m(**empty).should == [[], {}]
+        m(empty).should == [[{}], {}]
+
+        m(a: 1).should == [[], {a: 1}]
+        m({a: 1}).should == [[{a: 1}], {}]
+      end
+
+      it "works with proc { |*args, **kwargs| }" do
+        m = proc do |*args, **kwargs|
+          target(*args, **kwargs)
+        end
+
+        empty = {}
+        m.(**empty).should == [[], {}]
+        m.(empty).should == [[{}], {}]
+
+        m.(a: 1).should == [[], {a: 1}]
+        m.({a: 1}).should == [[{a: 1}], {}]
+
+        # no autosplatting for |*args, **kwargs|
+        m.([1, 2]).should == [[[1, 2]], {}]
+      end
+
+      it "works with -> (*args, **kwargs) {}" do
+        m = -> *args, **kwargs do
+          target(*args, **kwargs)
+        end
+
+        empty = {}
+        m.(**empty).should == [[], {}]
+        m.(empty).should == [[{}], {}]
+
+        m.(a: 1).should == [[], {a: 1}]
+        m.({a: 1}).should == [[{a: 1}], {}]
+      end
+
+      it "works with (...)" do
+        instance_eval <<~DEF
+        def m(...)
+          target(...)
+        end
+        DEF
+
+        empty = {}
+        m(**empty).should == [[], {}]
+        m(empty).should == [[{}], {}]
+
+        m(a: 1).should == [[], {a: 1}]
+        m({a: 1}).should == [[{a: 1}], {}]
+      end
+
+      it "works with call(*ruby2_keyword_args)" do
+        class << self
+          ruby2_keywords def m(*args)
+            target(*args)
+          end
+        end
+
+        empty = {}
+        m(**empty).should == [[], {}]
+        Hash.ruby2_keywords_hash?(empty).should == false
+        m(empty).should == [[{}], {}]
+        Hash.ruby2_keywords_hash?(empty).should == false
+
+        m(a: 1).should == [[], {a: 1}]
+        m({a: 1}).should == [[{a: 1}], {}]
+
+        kw = {a: 1}
+
+        m(**kw).should == [[], {a: 1}]
+        m(**kw)[1].should == kw
+        m(**kw)[1].should_not.equal?(kw)
+        Hash.ruby2_keywords_hash?(kw).should == false
+        Hash.ruby2_keywords_hash?(m(**kw)[1]).should == false
+
+        m(kw).should == [[{a: 1}], {}]
+        m(kw)[0][0].should.equal?(kw)
+        Hash.ruby2_keywords_hash?(kw).should == false
+      end
+
+      it "works with super(*ruby2_keyword_args)" do
+        parent = Class.new do
+          def m(*args, **kwargs)
+            [args, kwargs]
+          end
+        end
+
+        child = Class.new(parent) do
+          ruby2_keywords def m(*args)
+            super(*args)
+          end
+        end
+
+        obj = child.new
+
+        empty = {}
+        obj.m(**empty).should == [[], {}]
+        Hash.ruby2_keywords_hash?(empty).should == false
+        obj.m(empty).should == [[{}], {}]
+        Hash.ruby2_keywords_hash?(empty).should == false
+
+        obj.m(a: 1).should == [[], {a: 1}]
+        obj.m({a: 1}).should == [[{a: 1}], {}]
+
+        kw = {a: 1}
+
+        obj.m(**kw).should == [[], {a: 1}]
+        obj.m(**kw)[1].should == kw
+        obj.m(**kw)[1].should_not.equal?(kw)
+        Hash.ruby2_keywords_hash?(kw).should == false
+        Hash.ruby2_keywords_hash?(obj.m(**kw)[1]).should == false
+
+        obj.m(kw).should == [[{a: 1}], {}]
+        obj.m(kw)[0][0].should.equal?(kw)
+        Hash.ruby2_keywords_hash?(kw).should == false
+      end
+
+      it "works with zsuper" do
+        parent = Class.new do
+          def m(*args, **kwargs)
+            [args, kwargs]
+          end
+        end
+
+        child = Class.new(parent) do
+          ruby2_keywords def m(*args)
+            super
+          end
+        end
+
+        obj = child.new
+
+        empty = {}
+        obj.m(**empty).should == [[], {}]
+        Hash.ruby2_keywords_hash?(empty).should == false
+        obj.m(empty).should == [[{}], {}]
+        Hash.ruby2_keywords_hash?(empty).should == false
+
+        obj.m(a: 1).should == [[], {a: 1}]
+        obj.m({a: 1}).should == [[{a: 1}], {}]
+
+        kw = {a: 1}
+
+        obj.m(**kw).should == [[], {a: 1}]
+        obj.m(**kw)[1].should == kw
+        obj.m(**kw)[1].should_not.equal?(kw)
+        Hash.ruby2_keywords_hash?(kw).should == false
+        Hash.ruby2_keywords_hash?(obj.m(**kw)[1]).should == false
+
+        obj.m(kw).should == [[{a: 1}], {}]
+        obj.m(kw)[0][0].should.equal?(kw)
+        Hash.ruby2_keywords_hash?(kw).should == false
+      end
+
+      it "works with yield(*ruby2_keyword_args)" do
+        class << self
+          def y(args)
+            yield(*args)
+          end
+
+          ruby2_keywords def m(*outer_args)
+            y(outer_args, &-> *args, **kwargs { target(*args, **kwargs) })
+          end
+        end
+
+        empty = {}
+        m(**empty).should == [[], {}]
+        Hash.ruby2_keywords_hash?(empty).should == false
+        m(empty).should == [[{}], {}]
+        Hash.ruby2_keywords_hash?(empty).should == false
+
+        m(a: 1).should == [[], {a: 1}]
+        m({a: 1}).should == [[{a: 1}], {}]
+
+        kw = {a: 1}
+
+        m(**kw).should == [[], {a: 1}]
+        m(**kw)[1].should == kw
+        m(**kw)[1].should_not.equal?(kw)
+        Hash.ruby2_keywords_hash?(kw).should == false
+        Hash.ruby2_keywords_hash?(m(**kw)[1]).should == false
+
+        m(kw).should == [[{a: 1}], {}]
+        m(kw)[0][0].should.equal?(kw)
+        Hash.ruby2_keywords_hash?(kw).should == false
+      end
+
+      it "does not work with (*args)" do
+        class << self
+          def m(*args)
+            target(*args)
+          end
+        end
+
+        empty = {}
+        m(**empty).should == [[], {}]
+        m(empty).should == [[{}], {}]
+
+        m(a: 1).should == [[{a: 1}], {}]
+        m({a: 1}).should == [[{a: 1}], {}]
+      end
+    end
+  end
+end
diff --git a/spec/ruby/library/logger/device/close_spec.rb b/spec/ruby/library/logger/device/close_spec.rb
index d7d107fcce..7c5e118d56 100644
--- a/spec/ruby/library/logger/device/close_spec.rb
+++ b/spec/ruby/library/logger/device/close_spec.rb
@@ -15,14 +15,14 @@ describe "Logger::LogDevice#close" do
     rm_r @file_path
   end
 
-  ruby_version_is ""..."2.7" do
+  version_is Logger::VERSION, ""..."1.4.0" do
     it "closes the LogDevice's stream" do
       @device.close
       -> { @device.write("Test") }.should complain(/\Alog writing failed\./)
     end
   end
 
-  ruby_version_is "2.7" do
+  version_is Logger::VERSION, "1.4.0" do
     it "closes the LogDevice's stream" do
       @device.close
       -> { @device.write("Test") }.should complain(/\Alog shifting failed\./)
diff --git a/spec/ruby/library/logger/device/write_spec.rb b/spec/ruby/library/logger/device/write_spec.rb
index 5506bb2c38..cd2d7e27a9 100644
--- a/spec/ruby/library/logger/device/write_spec.rb
+++ b/spec/ruby/library/logger/device/write_spec.rb
@@ -35,14 +35,14 @@ describe "Logger::LogDevice#write" do
     rm_r path
   end
 
-  ruby_version_is ""..."2.7" do
+  version_is Logger::VERSION, ""..."1.4.0" do
     it "fails if the device is already closed" do
       @device.close
       -> { @device.write "foo" }.should complain(/\Alog writing failed\./)
     end
   end
 
-  ruby_version_is "2.7" do
+  version_is Logger::VERSION, "1.4.0" do
     it "fails if the device is already closed" do
       @device.close
       -> { @device.write "foo" }.should complain(/\Alog shifting failed\./)
diff --git a/spec/ruby/optional/capi/class_spec.rb b/spec/ruby/optional/capi/class_spec.rb
index a2d8b3e38a..a57b8f644f 100644
--- a/spec/ruby/optional/capi/class_spec.rb
+++ b/spec/ruby/optional/capi/class_spec.rb
@@ -108,17 +108,37 @@ describe "C-API Class function" do
 
   describe "rb_class_new_instance" do
     it "allocates and initializes a new object" do
-      o = @s.rb_class_new_instance(0, nil, CApiClassSpecs::Alloc)
+      o = @s.rb_class_new_instance([], CApiClassSpecs::Alloc)
       o.class.should == CApiClassSpecs::Alloc
       o.initialized.should be_true
     end
 
     it "passes arguments to the #initialize method" do
-      o = @s.rb_class_new_instance(2, [:one, :two], CApiClassSpecs::Alloc)
+      o = @s.rb_class_new_instance([:one, :two], CApiClassSpecs::Alloc)
       o.arguments.should == [:one, :two]
     end
   end
 
+  ruby_version_is "3.0" do
+    describe "rb_class_new_instance_kw" do
+      it "passes arguments and keywords to the #initialize method" do
+        obj = @s.rb_class_new_instance_kw([{pos: 1}, {kw: 2}], CApiClassSpecs::KeywordAlloc)
+        obj.args.should == [{pos: 1}]
+        obj.kwargs.should == {kw: 2}
+
+        obj = @s.rb_class_new_instance_kw([{}], CApiClassSpecs::KeywordAlloc)
+        obj.args.should == []
+        obj.kwargs.should == {}
+      end
+
+      it "raises TypeError if the last argument is not a Hash" do
+        -> {
+          @s.rb_class_new_instance_kw([42], CApiClassSpecs::KeywordAlloc)
+        }.should raise_error(TypeError, 'no implicit conversion of Integer into Hash')
+      end
+    end
+  end
+
   describe "rb_include_module" do
     it "includes a module into a class" do
       c = Class.new
diff --git a/spec/ruby/optional/capi/ext/class_spec.c b/spec/ruby/optional/capi/ext/class_spec.c
index 36b8c8f2f3..b860742906 100644
--- a/spec/ruby/optional/capi/ext/class_spec.c
+++ b/spec/ruby/optional/capi/ext/class_spec.c
@@ -61,18 +61,15 @@ static VALUE class_spec_rb_class_new(VALUE self, VALUE super) {
   return rb_class_new(super);
 }
 
-static VALUE class_spec_rb_class_new_instance(VALUE self,
-                                      VALUE nargs, VALUE args,
-                                      VALUE klass) {
-  int c_nargs = FIX2INT(nargs);
-  VALUE *c_args = (VALUE*)alloca(sizeof(VALUE) * c_nargs);
-  int i;
-
-  for (i = 0; i < c_nargs; i++)
-    c_args[i] = rb_ary_entry(args, i);
+static VALUE class_spec_rb_class_new_instance(VALUE self, VALUE args, VALUE klass) {
+  return rb_class_new_instance(RARRAY_LENINT(args), RARRAY_PTR(args), klass);
+}
 
-  return rb_class_new_instance(c_nargs, c_args, klass);
+#ifdef RUBY_VERSION_IS_3_0
+static VALUE class_spec_rb_class_new_instance_kw(VALUE self, VALUE args, VALUE klass) {
+  return rb_class_new_instance_kw(RARRAY_LENINT(args), RARRAY_PTR(args), klass, RB_PASS_KEYWORDS);
 }
+#endif
 
 static VALUE class_spec_rb_class_real(VALUE self, VALUE object) {
   if(rb_type_p(object, T_FIXNUM)) {
@@ -171,7 +168,10 @@ void Init_class_spec(void) {
   rb_define_method(cls, "rb_class_protected_instance_methods", class_spec_rb_class_protected_instance_methods, -1);
   rb_define_method(cls, "rb_class_private_instance_methods", class_spec_rb_class_private_instance_methods, -1);
   rb_define_method(cls, "rb_class_new", class_spec_rb_class_new, 1);
-  rb_define_method(cls, "rb_class_new_instance", class_spec_rb_class_new_instance, 3);
+  rb_define_method(cls, "rb_class_new_instance", class_spec_rb_class_new_instance, 2);
+#ifdef RUBY_VERSION_IS_3_0
+  rb_define_method(cls, "rb_class_new_instance_kw", class_spec_rb_class_new_instance_kw, 2);
+#endif
   rb_define_method(cls, "rb_class_real", class_spec_rb_class_real, 1);
   rb_define_method(cls, "rb_class_superclass", class_spec_rb_class_superclass, 1);
   rb_define_method(cls, "rb_cvar_defined", class_spec_cvar_defined, 2);
diff --git a/spec/ruby/optional/capi/ext/kernel_spec.c b/spec/ruby/optional/capi/ext/kernel_spec.c
index bbfeb198b7..46af8696a5 100644
--- a/spec/ruby/optional/capi/ext/kernel_spec.c
+++ b/spec/ruby/optional/capi/ext/kernel_spec.c
@@ -142,7 +142,7 @@ VALUE kernel_spec_call_proc_with_raised_exc(VALUE arg_array, VALUE raised_exc) {
 
   argc = 2;
 
-  return rb_funcall2(proc, rb_intern("call"), argc, argv);
+  return rb_funcallv(proc, rb_intern("call"), argc, argv);
 }
 
 VALUE kernel_spec_rb_rescue(VALUE self, VALUE main_proc, VALUE arg,
@@ -318,8 +318,22 @@ static VALUE kernel_spec_rb_make_backtrace(VALUE self) {
   return rb_make_backtrace();
 }
 
-static VALUE kernel_spec_rb_funcall3(VALUE self, VALUE obj, VALUE method) {
-  return rb_funcall3(obj, SYM2ID(method), 0, NULL);
+static VALUE kernel_spec_rb_funcallv(VALUE self, VALUE obj, VALUE method, VALUE args) {
+  return rb_funcallv(obj, SYM2ID(method), RARRAY_LENINT(args), RARRAY_PTR(args));
+}
+
+#ifdef RUBY_VERSION_IS_3_0
+static VALUE kernel_spec_rb_funcallv_kw(VALUE self, VALUE obj, VALUE method, VALUE args) {
+  return rb_funcallv_kw(obj, SYM2ID(method), RARRAY_LENINT(args), RARRAY_PTR(args), RB_PASS_KEYWORDS);
+}
+
+static VALUE kernel_spec_rb_keyword_given_p(int argc, VALUE *args, VALUE self) {
+  return rb_keyword_given_p() ? Qtrue : Qfalse;
+}
+#endif
+
+static VALUE kernel_spec_rb_funcallv_public(VALUE self, VALUE obj, VALUE method) {
+  return rb_funcallv_public(obj, SYM2ID(method), 0, NULL);
 }
 
 static VALUE kernel_spec_rb_funcall_with_block(VALUE self, VALUE obj, VALUE method, VALUE block) {
@@ -371,7 +385,12 @@ void Init_kernel_spec(void) {
   rb_define_method(cls, "rb_set_end_proc", kernel_spec_rb_set_end_proc, 1);
   rb_define_method(cls, "rb_f_sprintf", kernel_spec_rb_f_sprintf, 1);
   rb_define_method(cls, "rb_make_backtrace", kernel_spec_rb_make_backtrace, 0);
-  rb_define_method(cls, "rb_funcall3", kernel_spec_rb_funcall3, 2);
+  rb_define_method(cls, "rb_funcallv", kernel_spec_rb_funcallv, 3);
+#ifdef RUBY_VERSION_IS_3_0
+  rb_define_method(cls, "rb_funcallv_kw", kernel_spec_rb_funcallv_kw, 3);
+  rb_define_method(cls, "rb_keyword_given_p", kernel_spec_rb_keyword_given_p, -1);
+#endif
+  rb_define_method(cls, "rb_funcallv_public", kernel_spec_rb_funcallv_public, 2);
   rb_define_method(cls, "rb_funcall_many_args", kernel_spec_rb_funcall_many_args, 2);
   rb_define_method(cls, "rb_funcall_with_block", kernel_spec_rb_funcall_with_block, 3);
 }
diff --git a/spec/ruby/optional/capi/ext/symbol_spec.c b/spec/ruby/optional/capi/ext/symbol_spec.c
index 7d9a7b4379..ba88635faa 100644
--- a/spec/ruby/optional/capi/ext/symbol_spec.c
+++ b/spec/ruby/optional/capi/ext/symbol_spec.c
@@ -47,10 +47,19 @@ VALUE symbol_spec_rb_id2name(VALUE self, VALUE symbol) {
   return rb_str_new(c_str, strlen(c_str));
 }
 
+VALUE symbol_spec_rb_id2name_id_zero(VALUE self) {
+  const char* c_str = rb_id2name((ID) 0);
+  return c_str ? rb_str_new(c_str, strlen(c_str)) : Qnil;
+}
+
 VALUE symbol_spec_rb_id2str(VALUE self, VALUE symbol) {
   return rb_id2str(SYM2ID(symbol));
 }
 
+VALUE symbol_spec_rb_id2str_id_zero(VALUE self) {
+  return rb_id2str((ID) 0);
+}
+
 VALUE symbol_spec_rb_intern_str(VALUE self, VALUE str) {
   return ID2SYM(rb_intern_str(str));
 }
@@ -90,7 +99,9 @@ void Init_symbol_spec(void) {
   rb_define_method(cls, "rb_intern3", symbol_spec_rb_intern3, 3);
   rb_define_method(cls, "rb_intern3_c_compare", symbol_spec_rb_intern3_c_compare, 4);
   rb_define_method(cls, "rb_id2name", symbol_spec_rb_id2name, 1);
+  rb_define_method(cls, "rb_id2name_id_zero", symbol_spec_rb_id2name_id_zero, 0);
   rb_define_method(cls, "rb_id2str", symbol_spec_rb_id2str, 1);
+  rb_define_method(cls, "rb_id2str_id_zero", symbol_spec_rb_id2str_id_zero, 0);
   rb_define_method(cls, "rb_intern_str", symbol_spec_rb_intern_str, 1);
   rb_define_method(cls, "rb_check_symbol_cstr", symbol_spec_rb_check_symbol_cstr, 1);
   rb_define_method(cls, "rb_is_class_id", symbol_spec_rb_is_class_id, 1);
diff --git a/spec/ruby/optional/capi/fixtures/class.rb b/spec/ruby/optional/capi/fixtures/class.rb
index 193c7174e0..b463e3b4c3 100644
--- a/spec/ruby/optional/capi/fixtures/class.rb
+++ b/spec/ruby/optional/capi/fixtures/class.rb
@@ -15,6 +15,16 @@ class CApiClassSpecs
     end
   end
 
+  class KeywordAlloc
+    attr_reader :initialized, :args, :kwargs
+
+    def initialize(*args, **kwargs)
+      @initialized = true
+      @args = args
+      @kwargs = kwargs
+    end
+  end
+
   class Attr
     def initialize
       @foo, @bar, @baz = 1, 2, 3
diff --git a/spec/ruby/optional/capi/kernel_spec.rb b/spec/ruby/optional/capi/kernel_spec.rb
index 758d944da9..88545265d0 100644
--- a/spec/ruby/optional/capi/kernel_spec.rb
+++ b/spec/ruby/optional/capi/kernel_spec.rb
@@ -567,7 +567,64 @@ describe "C-API Kernel function" do
     end
   end
 
-  describe "rb_funcall3" do
+  describe "rb_funcallv" do
+    def empty
+      42
+    end
+
+    def sum(a, b)
+      a + b
+    end
+
+    it "calls a method" do
+      @s.rb_funcallv(self, :empty, []).should == 42
+      @s.rb_funcallv(self, :sum, [1, 2]).should == 3
+    end
+  end
+
+  ruby_version_is "3.0" do
+    describe "rb_funcallv_kw" do
+      it "passes keyword arguments to the callee" do
+        def m(*args, **kwargs)
+          [args, kwargs]
+        end
+
+        @s.rb_funcallv_kw(self, :m, [{}]).should == [[], {}]
+        @s.rb_funcallv_kw(self, :m, [{a: 1}]).should == [[], {a: 1}]
+        @s.rb_funcallv_kw(self, :m, [{b: 2}, {a: 1}]).should == [[{b: 2}], {a: 1}]
+        @s.rb_funcallv_kw(self, :m, [{b: 2}, {}]).should == [[{b: 2}], {}]
+      end
+
+      it "raises TypeError if the last argument is not a Hash" do
+        def m(*args, **kwargs)
+          [args, kwargs]
+        end
+
+        -> {
+          @s.rb_funcallv_kw(self, :m, [42])
+        }.should raise_error(TypeError, 'no implicit conversion of Integer into Hash')
+      end
+    end
+
+    describe "rb_keyword_given_p" do
+      it "returns whether keywords were given to the C extension method" do
+        h = {a: 1}
+        empty = {}
+        @s.rb_keyword_given_p(a: 1).should == true
+        @s.rb_keyword_given_p("foo" => "bar").should == true
+        @s.rb_keyword_given_p(**h).should == true
+
+        @s.rb_keyword_given_p(h).should == false
+        @s.rb_keyword_given_p().should == false
+        @s.rb_keyword_given_p(**empty).should == false
+
+        @s.rb_funcallv_kw(@s, :rb_keyword_given_p, [{a: 1}]).should == true
+        @s.rb_funcallv_kw(@s, :rb_keyword_given_p, [{}]).should == false
+      end
+    end
+  end
+
+  describe "rb_funcallv_public" do
     before :each do
       @obj = Object.new
       class << @obj
@@ -578,10 +635,11 @@ describe "C-API Kernel function" do
     end
 
     it "calls a public method" do
-      @s.rb_funcall3(@obj, :method_public).should == :method_public
+      @s.rb_funcallv_public(@obj, :method_public).should == :method_public
     end
+
     it "does not call a private method" do
-      -> { @s.rb_funcall3(@obj, :method_private) }.should raise_error(NoMethodError, /private/)
+      -> { @s.rb_funcallv_public(@obj, :method_private) }.should raise_error(NoMethodError, /private/)
     end
   end
 
@@ -599,6 +657,7 @@ describe "C-API Kernel function" do
       @s.rb_funcall_many_args(@obj, :many_args).should == 15.downto(1).to_a
     end
   end
+
   describe 'rb_funcall_with_block' do
     before :each do
       @obj = Object.new
diff --git a/spec/ruby/optional/capi/symbol_spec.rb b/spec/ruby/optional/capi/symbol_spec.rb
index b8fda34c0e..12c93c9f27 100644
--- a/spec/ruby/optional/capi/symbol_spec.rb
+++ b/spec/ruby/optional/capi/symbol_spec.rb
@@ -61,6 +61,10 @@ describe "C-API Symbol function" do
     it "converts a symbol to a C char array" do
       @s.rb_id2name(:test_symbol).should == "test_symbol"
     end
+
+    it "returns (char*) NULL for (ID) 0" do
+      @s.rb_id2name_id_zero.should == nil
+    end
   end
 
   describe "rb_id2str" do
@@ -72,6 +76,10 @@ describe "C-API Symbol function" do
       str = "test_symbol".encode(Encoding::UTF_16LE)
       @s.rb_id2str(str.to_sym).encoding.should == Encoding::UTF_16LE
     end
+
+    it "returns (VALUE) 0 = Qfalse for (ID) 0" do
+      @s.rb_id2str_id_zero.should == false
+    end
   end
 
   describe "rb_intern_str" do
diff --git a/spec/ruby/shared/kernel/raise.rb b/spec/ruby/shared/kernel/raise.rb
index 765ba0f929..82fb0333c8 100644
--- a/spec/ruby/shared/kernel/raise.rb
+++ b/spec/ruby/shared/kernel/raise.rb
@@ -29,11 +29,41 @@ describe :kernel_raise, shared: true do
         @data = data
       end
     end
-    -> { @object.raise(data_error, {:data => 42}) }.should raise_error(data_error) do |ex|
-      ex.data.should == {:data => 42}
+
+    -> { @object.raise(data_error, {data: 42}) }.should raise_error(data_error) do |ex|
+      ex.data.should == {data: 42}
+    end
+  end
+
+  # https://bugs.ruby-lang.org/issues/8257#note-36
+  it "allows extra keyword arguments for compatibility" do
+    data_error = Class.new(StandardError) do
+      attr_reader :data
+      def initialize(data)
+        @data = data
+      end
+    end
+
+    -> { @object.raise(data_error, data: 42) }.should raise_error(data_error) do |ex|
+      ex.data.should == {data: 42}
     end
   end
 
+  it "does not allow message and extra keyword arguments" do
+    data_error = Class.new(StandardError) do
+      attr_reader :data
+      def initialize(data)
+        @data = data
+      end
+    end
+
+    -> { @object.raise(data_error, {a: 1}, b: 2) }.should raise_error(StandardError) do |e|
+      [TypeError, ArgumentError].should.include?(e.class)
+    end
+
+    -> { @object.raise(data_error, {a: 1}, [], b: 2) }.should raise_error(ArgumentError)
+  end
+
   it "raises RuntimeError if no exception class is given" do
     -> { @object.raise }.should raise_error(RuntimeError, "")
   end
diff --git a/spec/ruby/shared/process/exit.rb b/spec/ruby/shared/process/exit.rb
index ae8abaea40..7d901f1f1e 100644
--- a/spec/ruby/shared/process/exit.rb
+++ b/spec/ruby/shared/process/exit.rb
@@ -21,6 +21,12 @@ describe :process_exit, shared: true do
     end
   end
 
+  it "raises a SystemExit with message 'exit'" do
+    -> { @object.exit }.should raise_error(SystemExit) { |e|
+      e.message.should == "exit"
+    }
+  end
+
   it "tries to convert the passed argument to an Integer using #to_int" do
     obj = mock('5')
     obj.should_receive(:to_int).and_return(5)