Update to ruby/spec@7de852d

14 files changed, 594 insertions, 631 deletions

diff --git a/spec/ruby/core/io/external_encoding_spec.rb b/spec/ruby/core/io/external_encoding_spec.rb
index e625484670..3581019207 100644
--- a/spec/ruby/core/io/external_encoding_spec.rb
+++ b/spec/ruby/core/io/external_encoding_spec.rb
@@ -1,218 +1,216 @@
 require_relative '../../spec_helper'
 
-with_feature :encoding do
-  describe :io_external_encoding_write, shared: true do
+describe :io_external_encoding_write, shared: true do
+  describe "when Encoding.default_internal is nil" do
+    before :each do
+      Encoding.default_internal = nil
+    end
+
+    it "returns nil" do
+      @io = new_io @name, @object
+      Encoding.default_external = Encoding::IBM437
+      @io.external_encoding.should be_nil
+    end
+
+    it "returns the external encoding specified when the instance was created" do
+      @io = new_io @name, "#{@object}:ibm866"
+      Encoding.default_external = Encoding::IBM437
+      @io.external_encoding.should equal(Encoding::IBM866)
+    end
+
+    it "returns the encoding set by #set_encoding" do
+      @io = new_io @name, "#{@object}:ibm866"
+      @io.set_encoding Encoding::EUC_JP, nil
+      @io.external_encoding.should equal(Encoding::EUC_JP)
+    end
+  end
+
+  describe "when Encoding.default_external != Encoding.default_internal" do
+    before :each do
+      Encoding.default_external = Encoding::IBM437
+      Encoding.default_internal = Encoding::IBM866
+    end
+
+    it "returns the value of Encoding.default_external when the instance was created" do
+      @io = new_io @name, @object
+      Encoding.default_external = Encoding::UTF_8
+      @io.external_encoding.should equal(Encoding::IBM437)
+    end
+
+    it "returns the external encoding specified when the instance was created" do
+      @io = new_io @name, "#{@object}:ibm866"
+      Encoding.default_external = Encoding::IBM437
+      @io.external_encoding.should equal(Encoding::IBM866)
+    end
+
+    it "returns the encoding set by #set_encoding" do
+      @io = new_io @name, "#{@object}:ibm866"
+      @io.set_encoding Encoding::EUC_JP, nil
+      @io.external_encoding.should equal(Encoding::EUC_JP)
+    end
+  end
+
+  describe "when Encoding.default_external == Encoding.default_internal" do
+    before :each do
+      Encoding.default_external = Encoding::IBM866
+      Encoding.default_internal = Encoding::IBM866
+    end
+
+    it "returns the value of Encoding.default_external when the instance was created" do
+      @io = new_io @name, @object
+      Encoding.default_external = Encoding::UTF_8
+      @io.external_encoding.should equal(Encoding::IBM866)
+    end
+
+    it "returns the external encoding specified when the instance was created" do
+      @io = new_io @name, "#{@object}:ibm866"
+      Encoding.default_external = Encoding::IBM437
+      @io.external_encoding.should equal(Encoding::IBM866)
+    end
+
+    it "returns the encoding set by #set_encoding" do
+      @io = new_io @name, "#{@object}:ibm866"
+      @io.set_encoding Encoding::EUC_JP, nil
+      @io.external_encoding.should equal(Encoding::EUC_JP)
+    end
+  end
+end
+
+describe "IO#external_encoding" do
+  before :each do
+    @external = Encoding.default_external
+    @internal = Encoding.default_internal
+
+    @name = tmp("io_external_encoding")
+    touch(@name)
+  end
+
+  after :each do
+    Encoding.default_external = @external
+    Encoding.default_internal = @internal
+
+    @io.close if @io
+    rm_r @name
+  end
+
+  describe "with 'r' mode" do
     describe "when Encoding.default_internal is nil" do
       before :each do
         Encoding.default_internal = nil
+        Encoding.default_external = Encoding::IBM866
       end
 
-      it "returns nil" do
-        @io = new_io @name, @object
+      it "returns Encoding.default_external if the external encoding is not set" do
+        @io = new_io @name, "r"
+        @io.external_encoding.should equal(Encoding::IBM866)
+      end
+
+      it "returns Encoding.default_external when that encoding is changed after the instance is created" do
+        @io = new_io @name, "r"
         Encoding.default_external = Encoding::IBM437
-        @io.external_encoding.should be_nil
+        @io.external_encoding.should equal(Encoding::IBM437)
       end
 
       it "returns the external encoding specified when the instance was created" do
-        @io = new_io @name, "#{@object}:ibm866"
+        @io = new_io @name, "r:utf-8"
         Encoding.default_external = Encoding::IBM437
-        @io.external_encoding.should equal(Encoding::IBM866)
+        @io.external_encoding.should equal(Encoding::UTF_8)
       end
 
       it "returns the encoding set by #set_encoding" do
-        @io = new_io @name, "#{@object}:ibm866"
+        @io = new_io @name, "r:utf-8"
         @io.set_encoding Encoding::EUC_JP, nil
         @io.external_encoding.should equal(Encoding::EUC_JP)
       end
     end
 
-    describe "when Encoding.default_external != Encoding.default_internal" do
+    describe "when Encoding.default_external == Encoding.default_internal" do
       before :each do
-        Encoding.default_external = Encoding::IBM437
+        Encoding.default_external = Encoding::IBM866
         Encoding.default_internal = Encoding::IBM866
       end
 
       it "returns the value of Encoding.default_external when the instance was created" do
-        @io = new_io @name, @object
-        Encoding.default_external = Encoding::UTF_8
-        @io.external_encoding.should equal(Encoding::IBM437)
+        @io = new_io @name, "r"
+        Encoding.default_external = Encoding::IBM437
+        @io.external_encoding.should equal(Encoding::IBM866)
       end
 
       it "returns the external encoding specified when the instance was created" do
-        @io = new_io @name, "#{@object}:ibm866"
+        @io = new_io @name, "r:utf-8"
         Encoding.default_external = Encoding::IBM437
-        @io.external_encoding.should equal(Encoding::IBM866)
+        @io.external_encoding.should equal(Encoding::UTF_8)
       end
 
       it "returns the encoding set by #set_encoding" do
-        @io = new_io @name, "#{@object}:ibm866"
+        @io = new_io @name, "r:utf-8"
         @io.set_encoding Encoding::EUC_JP, nil
         @io.external_encoding.should equal(Encoding::EUC_JP)
       end
     end
 
-    describe "when Encoding.default_external == Encoding.default_internal" do
+    describe "when Encoding.default_external != Encoding.default_internal" do
       before :each do
-        Encoding.default_external = Encoding::IBM866
+        Encoding.default_external = Encoding::IBM437
         Encoding.default_internal = Encoding::IBM866
       end
 
-      it "returns the value of Encoding.default_external when the instance was created" do
-        @io = new_io @name, @object
-        Encoding.default_external = Encoding::UTF_8
-        @io.external_encoding.should equal(Encoding::IBM866)
-      end
 
       it "returns the external encoding specified when the instance was created" do
-        @io = new_io @name, "#{@object}:ibm866"
+        @io = new_io @name, "r:utf-8"
         Encoding.default_external = Encoding::IBM437
-        @io.external_encoding.should equal(Encoding::IBM866)
+        @io.external_encoding.should equal(Encoding::UTF_8)
       end
 
       it "returns the encoding set by #set_encoding" do
-        @io = new_io @name, "#{@object}:ibm866"
+        @io = new_io @name, "r:utf-8"
         @io.set_encoding Encoding::EUC_JP, nil
         @io.external_encoding.should equal(Encoding::EUC_JP)
       end
     end
   end
 
-  describe "IO#external_encoding" do
-    before :each do
-      @external = Encoding.default_external
-      @internal = Encoding.default_internal
-
-      @name = tmp("io_external_encoding")
-      touch(@name)
-    end
-
-    after :each do
-      Encoding.default_external = @external
-      Encoding.default_internal = @internal
-
-      @io.close if @io
-      rm_r @name
-    end
-
-    describe "with 'r' mode" do
-      describe "when Encoding.default_internal is nil" do
-        before :each do
-          Encoding.default_internal = nil
-          Encoding.default_external = Encoding::IBM866
-        end
-
-        it "returns Encoding.default_external if the external encoding is not set" do
-          @io = new_io @name, "r"
-          @io.external_encoding.should equal(Encoding::IBM866)
-        end
-
-        it "returns Encoding.default_external when that encoding is changed after the instance is created" do
-          @io = new_io @name, "r"
-          Encoding.default_external = Encoding::IBM437
-          @io.external_encoding.should equal(Encoding::IBM437)
-        end
-
-        it "returns the external encoding specified when the instance was created" do
-          @io = new_io @name, "r:utf-8"
-          Encoding.default_external = Encoding::IBM437
-          @io.external_encoding.should equal(Encoding::UTF_8)
-        end
-
-        it "returns the encoding set by #set_encoding" do
-          @io = new_io @name, "r:utf-8"
-          @io.set_encoding Encoding::EUC_JP, nil
-          @io.external_encoding.should equal(Encoding::EUC_JP)
-        end
-      end
-
-      describe "when Encoding.default_external == Encoding.default_internal" do
-        before :each do
-          Encoding.default_external = Encoding::IBM866
-          Encoding.default_internal = Encoding::IBM866
-        end
-
-        it "returns the value of Encoding.default_external when the instance was created" do
-          @io = new_io @name, "r"
-          Encoding.default_external = Encoding::IBM437
-          @io.external_encoding.should equal(Encoding::IBM866)
-        end
-
-        it "returns the external encoding specified when the instance was created" do
-          @io = new_io @name, "r:utf-8"
-          Encoding.default_external = Encoding::IBM437
-          @io.external_encoding.should equal(Encoding::UTF_8)
-        end
-
-        it "returns the encoding set by #set_encoding" do
-          @io = new_io @name, "r:utf-8"
-          @io.set_encoding Encoding::EUC_JP, nil
-          @io.external_encoding.should equal(Encoding::EUC_JP)
-        end
-      end
-
-      describe "when Encoding.default_external != Encoding.default_internal" do
-        before :each do
-          Encoding.default_external = Encoding::IBM437
-          Encoding.default_internal = Encoding::IBM866
-        end
-
-
-        it "returns the external encoding specified when the instance was created" do
-          @io = new_io @name, "r:utf-8"
-          Encoding.default_external = Encoding::IBM437
-          @io.external_encoding.should equal(Encoding::UTF_8)
-        end
-
-        it "returns the encoding set by #set_encoding" do
-          @io = new_io @name, "r:utf-8"
-          @io.set_encoding Encoding::EUC_JP, nil
-          @io.external_encoding.should equal(Encoding::EUC_JP)
-        end
-      end
+  describe "with 'rb' mode" do
+    it "returns Encoding::ASCII_8BIT" do
+      @io = new_io @name, "rb"
+      @io.external_encoding.should equal(Encoding::ASCII_8BIT)
     end
 
-    describe "with 'rb' mode" do
-      it "returns Encoding::ASCII_8BIT" do
-        @io = new_io @name, "rb"
-        @io.external_encoding.should equal(Encoding::ASCII_8BIT)
-      end
-
-      it "returns the external encoding specified by the mode argument" do
-        @io = new_io @name, "rb:ibm437"
-        @io.external_encoding.should equal(Encoding::IBM437)
-      end
-    end
-
-    describe "with 'r+' mode" do
-      it_behaves_like :io_external_encoding_write, nil, "r+"
+    it "returns the external encoding specified by the mode argument" do
+      @io = new_io @name, "rb:ibm437"
+      @io.external_encoding.should equal(Encoding::IBM437)
     end
+  end
 
-    describe "with 'w' mode" do
-      it_behaves_like :io_external_encoding_write, nil, "w"
-    end
+  describe "with 'r+' mode" do
+    it_behaves_like :io_external_encoding_write, nil, "r+"
+  end
 
-    describe "with 'wb' mode" do
-      it "returns Encoding::ASCII_8BIT" do
-        @io = new_io @name, "wb"
-        @io.external_encoding.should equal(Encoding::ASCII_8BIT)
-      end
+  describe "with 'w' mode" do
+    it_behaves_like :io_external_encoding_write, nil, "w"
+  end
 
-      it "returns the external encoding specified by the mode argument" do
-        @io = new_io @name, "wb:ibm437"
-        @io.external_encoding.should equal(Encoding::IBM437)
-      end
+  describe "with 'wb' mode" do
+    it "returns Encoding::ASCII_8BIT" do
+      @io = new_io @name, "wb"
+      @io.external_encoding.should equal(Encoding::ASCII_8BIT)
     end
 
-    describe "with 'w+' mode" do
-      it_behaves_like :io_external_encoding_write, nil, "w+"
+    it "returns the external encoding specified by the mode argument" do
+      @io = new_io @name, "wb:ibm437"
+      @io.external_encoding.should equal(Encoding::IBM437)
     end
+  end
 
-    describe "with 'a' mode" do
-      it_behaves_like :io_external_encoding_write, nil, "a"
-    end
+  describe "with 'w+' mode" do
+    it_behaves_like :io_external_encoding_write, nil, "w+"
+  end
 
-    describe "with 'a+' mode" do
-      it_behaves_like :io_external_encoding_write, nil, "a+"
-    end
+  describe "with 'a' mode" do
+    it_behaves_like :io_external_encoding_write, nil, "a"
+  end
+
+  describe "with 'a+' mode" do
+    it_behaves_like :io_external_encoding_write, nil, "a+"
   end
 end
diff --git a/spec/ruby/core/io/fixtures/classes.rb b/spec/ruby/core/io/fixtures/classes.rb
index a771e3d929..460dd62387 100644
--- a/spec/ruby/core/io/fixtures/classes.rb
+++ b/spec/ruby/core/io/fixtures/classes.rb
@@ -118,10 +118,10 @@ module IOSpecs
 
   # Creates an IO instance for an existing fixture file. The
   # file should obviously not be deleted.
-  def self.io_fixture(name, options_or_mode="r:utf-8")
+  def self.io_fixture(name, mode = "r:utf-8")
     path = fixture __FILE__, name
     name = path if File.exist? path
-    new_io name, options_or_mode
+    new_io(name, mode)
   end
 
   # Returns a closed instance of IO that was opened to reference
diff --git a/spec/ruby/core/io/foreach_spec.rb b/spec/ruby/core/io/foreach_spec.rb
index c5c1178787..c2276cf544 100644
--- a/spec/ruby/core/io/foreach_spec.rb
+++ b/spec/ruby/core/io/foreach_spec.rb
@@ -24,7 +24,7 @@ describe "IO.foreach" do
       ScratchPad.recorded.should == ["hello\n", "line2\n"]
     end
 
-    with_feature :fork do
+    platform_is_not :windows do
       it "gets data from a fork when passed -" do
         parent_pid = $$
 
diff --git a/spec/ruby/core/io/gets_spec.rb b/spec/ruby/core/io/gets_spec.rb
index 525c7547cd..ac763f2a13 100644
--- a/spec/ruby/core/io/gets_spec.rb
+++ b/spec/ruby/core/io/gets_spec.rb
@@ -156,11 +156,11 @@ describe "IO#gets" do
   end
 
   it "raises an IOError if the stream is opened for append only" do
-    lambda { File.open(@name, fmode("a:utf-8")) { |f| f.gets } }.should raise_error(IOError)
+    lambda { File.open(@name, "a:utf-8") { |f| f.gets } }.should raise_error(IOError)
   end
 
   it "raises an IOError if the stream is opened for writing only" do
-    lambda { File.open(@name, fmode("w:utf-8")) { |f| f.gets } }.should raise_error(IOError)
+    lambda { File.open(@name, "w:utf-8") { |f| f.gets } }.should raise_error(IOError)
   end
 end
 
@@ -168,7 +168,7 @@ describe "IO#gets" do
   before :each do
     @name = tmp("io_gets")
     touch(@name) { |f| f.write "one\n\ntwo\n\nthree\nfour\n" }
-    @io = new_io @name, fmode("r:utf-8")
+    @io = new_io @name, "r:utf-8"
   end
 
   after :each do
@@ -232,7 +232,7 @@ describe "IO#gets" do
     # create data "朝日" + "\xE3\x81" * 100 to avoid utf-8 conflicts
     data = "朝日" + ([227,129].pack('C*') * 100).force_encoding('utf-8')
     touch(@name) { |f| f.write data }
-    @io = new_io @name, fmode("r:utf-8")
+    @io = new_io @name, "r:utf-8"
   end
 
   after :each do
diff --git a/spec/ruby/core/io/initialize_spec.rb b/spec/ruby/core/io/initialize_spec.rb
index 5bf194f15c..4858e0360c 100644
--- a/spec/ruby/core/io/initialize_spec.rb
+++ b/spec/ruby/core/io/initialize_spec.rb
@@ -13,26 +13,18 @@ describe "IO#initialize" do
     rm_r @name
   end
 
-  # File descriptor numbers are not predictable in multi-threaded code;
-  # MJIT will be opening/closing files the background
-  without_feature :mjit do
-    it "reassociates the IO instance with the new descriptor when passed a Fixnum" do
-      fd = new_fd @name, "r:utf-8"
-      @io.send :initialize, fd, 'r'
-      @io.fileno.should == fd
-      # initialize has closed the old descriptor
-      lambda { IO.for_fd(@fd).close }.should raise_error(Errno::EBADF)
-    end
-
-    it "calls #to_int to coerce the object passed as an fd" do
-      obj = mock('fileno')
-      fd = new_fd @name, "r:utf-8"
-      obj.should_receive(:to_int).and_return(fd)
-      @io.send :initialize, obj, 'r'
-      @io.fileno.should == fd
-      # initialize has closed the old descriptor
-      lambda { IO.for_fd(@fd).close }.should raise_error(Errno::EBADF)
-    end
+  it "reassociates the IO instance with the new descriptor when passed a Fixnum" do
+    fd = new_fd @name, "r:utf-8"
+    @io.send :initialize, fd, 'r'
+    @io.fileno.should == fd
+  end
+
+  it "calls #to_int to coerce the object passed as an fd" do
+    obj = mock('fileno')
+    fd = new_fd @name, "r:utf-8"
+    obj.should_receive(:to_int).and_return(fd)
+    @io.send :initialize, obj, 'r'
+    @io.fileno.should == fd
   end
 
   it "raises a TypeError when passed an IO" do
diff --git a/spec/ruby/core/io/internal_encoding_spec.rb b/spec/ruby/core/io/internal_encoding_spec.rb
index a4f13fa100..772cdeeaaf 100644
--- a/spec/ruby/core/io/internal_encoding_spec.rb
+++ b/spec/ruby/core/io/internal_encoding_spec.rb
@@ -1,140 +1,138 @@
 require_relative '../../spec_helper'
 
-with_feature :encoding do
-  describe :io_internal_encoding, shared: true do
-    describe "when Encoding.default_internal is not set" do
-      before :each do
-        Encoding.default_internal = nil
-      end
-
-      it "returns nil if the internal encoding is not set" do
-        @io = new_io @name, @object
-        @io.internal_encoding.should be_nil
-      end
-
-      it "returns nil if Encoding.default_internal is changed after the instance is created" do
-        @io = new_io @name, @object
-        Encoding.default_internal = Encoding::IBM437
-        @io.internal_encoding.should be_nil
-      end
-
-      it "returns the value set when the instance was created" do
-        @io = new_io @name, "#{@object}:utf-8:euc-jp"
-        Encoding.default_internal = Encoding::IBM437
-        @io.internal_encoding.should equal(Encoding::EUC_JP)
-      end
-
-      it "returns the value set by #set_encoding" do
-        @io = new_io @name, @object
-        @io.set_encoding(Encoding::US_ASCII, Encoding::IBM437)
-        @io.internal_encoding.should equal(Encoding::IBM437)
-      end
-    end
-
-    describe "when Encoding.default_internal == Encoding.default_external" do
-      before :each do
-        Encoding.default_external = Encoding::IBM866
-        Encoding.default_internal = Encoding::IBM866
-      end
-
-      it "returns nil" do
-        @io = new_io @name, @object
-        @io.internal_encoding.should be_nil
-      end
-
-      it "returns nil regardless of Encoding.default_internal changes" do
-        @io = new_io @name, @object
-        Encoding.default_internal = Encoding::IBM437
-        @io.internal_encoding.should be_nil
-      end
-    end
-
-    describe "when Encoding.default_internal != Encoding.default_external" do
-      before :each do
-        Encoding.default_external = Encoding::IBM437
-        Encoding.default_internal = Encoding::IBM866
-      end
-
-      it "returns the value of Encoding.default_internal when the instance was created if the internal encoding is not set" do
-        @io = new_io @name, @object
-        @io.internal_encoding.should equal(Encoding::IBM866)
-      end
-
-      it "does not change when Encoding.default_internal is changed" do
-        @io = new_io @name, @object
-        Encoding.default_internal = Encoding::IBM437
-        @io.internal_encoding.should equal(Encoding::IBM866)
-      end
-
-      it "returns the internal encoding set when the instance was created" do
-        @io = new_io @name, "#{@object}:utf-8:euc-jp"
-        @io.internal_encoding.should equal(Encoding::EUC_JP)
-      end
-
-      it "does not change when set and Encoding.default_internal is changed" do
-        @io = new_io @name, "#{@object}:utf-8:euc-jp"
-        Encoding.default_internal = Encoding::IBM437
-        @io.internal_encoding.should equal(Encoding::EUC_JP)
-      end
-
-      it "returns the value set by #set_encoding" do
-        @io = new_io @name, @object
-        @io.set_encoding(Encoding::US_ASCII, Encoding::IBM437)
-        @io.internal_encoding.should equal(Encoding::IBM437)
-      end
-
-      it "returns nil when Encoding.default_external is ASCII-8BIT and the internal encoding is not set" do
-        Encoding.default_external = Encoding::ASCII_8BIT
-        @io = new_io @name, @object
-        @io.internal_encoding.should be_nil
-      end
-
-      it "returns nil when the external encoding is ASCII-8BIT and the internal encoding is not set" do
-        @io = new_io @name, "#{@object}:ascii-8bit"
-        @io.internal_encoding.should be_nil
-      end
+describe :io_internal_encoding, shared: true do
+  describe "when Encoding.default_internal is not set" do
+    before :each do
+      Encoding.default_internal = nil
+    end
+
+    it "returns nil if the internal encoding is not set" do
+      @io = new_io @name, @object
+      @io.internal_encoding.should be_nil
+    end
+
+    it "returns nil if Encoding.default_internal is changed after the instance is created" do
+      @io = new_io @name, @object
+      Encoding.default_internal = Encoding::IBM437
+      @io.internal_encoding.should be_nil
+    end
+
+    it "returns the value set when the instance was created" do
+      @io = new_io @name, "#{@object}:utf-8:euc-jp"
+      Encoding.default_internal = Encoding::IBM437
+      @io.internal_encoding.should equal(Encoding::EUC_JP)
+    end
+
+    it "returns the value set by #set_encoding" do
+      @io = new_io @name, @object
+      @io.set_encoding(Encoding::US_ASCII, Encoding::IBM437)
+      @io.internal_encoding.should equal(Encoding::IBM437)
     end
   end
 
-  describe "IO#internal_encoding" do
+  describe "when Encoding.default_internal == Encoding.default_external" do
     before :each do
-      @external = Encoding.default_external
-      @internal = Encoding.default_internal
+      Encoding.default_external = Encoding::IBM866
+      Encoding.default_internal = Encoding::IBM866
+    end
+
+    it "returns nil" do
+      @io = new_io @name, @object
+      @io.internal_encoding.should be_nil
+    end
 
-      @name = tmp("io_internal_encoding")
-      touch(@name)
+    it "returns nil regardless of Encoding.default_internal changes" do
+      @io = new_io @name, @object
+      Encoding.default_internal = Encoding::IBM437
+      @io.internal_encoding.should be_nil
     end
+  end
 
-    after :each do
-      @io.close if @io
-      rm_r @name
+  describe "when Encoding.default_internal != Encoding.default_external" do
+    before :each do
+      Encoding.default_external = Encoding::IBM437
+      Encoding.default_internal = Encoding::IBM866
+    end
 
-      Encoding.default_external = @external
-      Encoding.default_internal = @internal
+    it "returns the value of Encoding.default_internal when the instance was created if the internal encoding is not set" do
+      @io = new_io @name, @object
+      @io.internal_encoding.should equal(Encoding::IBM866)
     end
 
-    describe "with 'r' mode" do
-      it_behaves_like :io_internal_encoding, nil, "r"
+    it "does not change when Encoding.default_internal is changed" do
+      @io = new_io @name, @object
+      Encoding.default_internal = Encoding::IBM437
+      @io.internal_encoding.should equal(Encoding::IBM866)
     end
 
-    describe "with 'r+' mode" do
-      it_behaves_like :io_internal_encoding, nil, "r+"
+    it "returns the internal encoding set when the instance was created" do
+      @io = new_io @name, "#{@object}:utf-8:euc-jp"
+      @io.internal_encoding.should equal(Encoding::EUC_JP)
     end
 
-    describe "with 'w' mode" do
-      it_behaves_like :io_internal_encoding, nil, "w"
+    it "does not change when set and Encoding.default_internal is changed" do
+      @io = new_io @name, "#{@object}:utf-8:euc-jp"
+      Encoding.default_internal = Encoding::IBM437
+      @io.internal_encoding.should equal(Encoding::EUC_JP)
     end
 
-    describe "with 'w+' mode" do
-      it_behaves_like :io_internal_encoding, nil, "w+"
+    it "returns the value set by #set_encoding" do
+      @io = new_io @name, @object
+      @io.set_encoding(Encoding::US_ASCII, Encoding::IBM437)
+      @io.internal_encoding.should equal(Encoding::IBM437)
     end
 
-    describe "with 'a' mode" do
-      it_behaves_like :io_internal_encoding, nil, "a"
+    it "returns nil when Encoding.default_external is ASCII-8BIT and the internal encoding is not set" do
+      Encoding.default_external = Encoding::ASCII_8BIT
+      @io = new_io @name, @object
+      @io.internal_encoding.should be_nil
     end
 
-    describe "with 'a+' mode" do
-      it_behaves_like :io_internal_encoding, nil, "a+"
+    it "returns nil when the external encoding is ASCII-8BIT and the internal encoding is not set" do
+      @io = new_io @name, "#{@object}:ascii-8bit"
+      @io.internal_encoding.should be_nil
     end
   end
 end
+
+describe "IO#internal_encoding" do
+  before :each do
+    @external = Encoding.default_external
+    @internal = Encoding.default_internal
+
+    @name = tmp("io_internal_encoding")
+    touch(@name)
+  end
+
+  after :each do
+    @io.close if @io
+    rm_r @name
+
+    Encoding.default_external = @external
+    Encoding.default_internal = @internal
+  end
+
+  describe "with 'r' mode" do
+    it_behaves_like :io_internal_encoding, nil, "r"
+  end
+
+  describe "with 'r+' mode" do
+    it_behaves_like :io_internal_encoding, nil, "r+"
+  end
+
+  describe "with 'w' mode" do
+    it_behaves_like :io_internal_encoding, nil, "w"
+  end
+
+  describe "with 'w+' mode" do
+    it_behaves_like :io_internal_encoding, nil, "w+"
+  end
+
+  describe "with 'a' mode" do
+    it_behaves_like :io_internal_encoding, nil, "a"
+  end
+
+  describe "with 'a+' mode" do
+    it_behaves_like :io_internal_encoding, nil, "a+"
+  end
+end
diff --git a/spec/ruby/core/io/popen_spec.rb b/spec/ruby/core/io/popen_spec.rb
index d15ac48fe4..289bb076e4 100644
--- a/spec/ruby/core/io/popen_spec.rb
+++ b/spec/ruby/core/io/popen_spec.rb
@@ -136,7 +136,7 @@ describe "IO.popen" do
     end
   end
 
-  with_feature :fork do
+  platform_is_not :windows do
     it "starts returns a forked process if the command is -" do
       io = IO.popen("-")
 
@@ -153,22 +153,20 @@ describe "IO.popen" do
     end
   end
 
-  with_feature :encoding do
-    it "has the given external encoding" do
-      @io = IO.popen(ruby_cmd('exit'), external_encoding: Encoding::EUC_JP)
-      @io.external_encoding.should == Encoding::EUC_JP
-    end
+  it "has the given external encoding" do
+    @io = IO.popen(ruby_cmd('exit'), external_encoding: Encoding::EUC_JP)
+    @io.external_encoding.should == Encoding::EUC_JP
+  end
 
-    it "has the given internal encoding" do
-      @io = IO.popen(ruby_cmd('exit'), internal_encoding: Encoding::EUC_JP)
-      @io.internal_encoding.should == Encoding::EUC_JP
-    end
+  it "has the given internal encoding" do
+    @io = IO.popen(ruby_cmd('exit'), internal_encoding: Encoding::EUC_JP)
+    @io.internal_encoding.should == Encoding::EUC_JP
+  end
 
-    it "sets the internal encoding to nil if it's the same as the external encoding" do
-      @io = IO.popen(ruby_cmd('exit'), external_encoding: Encoding::EUC_JP,
-                            internal_encoding: Encoding::EUC_JP)
-      @io.internal_encoding.should be_nil
-    end
+  it "sets the internal encoding to nil if it's the same as the external encoding" do
+    @io = IO.popen(ruby_cmd('exit'), external_encoding: Encoding::EUC_JP,
+                          internal_encoding: Encoding::EUC_JP)
+    @io.internal_encoding.should be_nil
   end
 
   context "with a leading ENV Hash" do
diff --git a/spec/ruby/core/io/puts_spec.rb b/spec/ruby/core/io/puts_spec.rb
index e99cffb00f..e8d599730f 100644
--- a/spec/ruby/core/io/puts_spec.rb
+++ b/spec/ruby/core/io/puts_spec.rb
@@ -114,28 +114,26 @@ describe "IO#puts" do
     lambda { IOSpecs.closed_io.puts("stuff") }.should raise_error(IOError)
   end
 
-  with_feature :encoding do
-    it "writes crlf when IO is opened with newline: :crlf" do
-      File.open(@name, 'wt', newline: :crlf) do |file|
-        file.puts
-      end
-      File.binread(@name).should == "\r\n"
+  it "writes crlf when IO is opened with newline: :crlf" do
+    File.open(@name, 'wt', newline: :crlf) do |file|
+      file.puts
     end
+    File.binread(@name).should == "\r\n"
+  end
 
-    it "writes cr when IO is opened with newline: :cr" do
-      File.open(@name, 'wt', newline: :cr) do |file|
-        file.puts
-      end
-      File.binread(@name).should == "\r"
+  it "writes cr when IO is opened with newline: :cr" do
+    File.open(@name, 'wt', newline: :cr) do |file|
+      file.puts
     end
+    File.binread(@name).should == "\r"
+  end
 
-    platform_is_not :windows do # https://bugs.ruby-lang.org/issues/12436
-      it "writes lf when IO is opened with newline: :lf" do
-        File.open(@name, 'wt', newline: :lf) do |file|
-          file.puts
-        end
-        File.binread(@name).should == "\n"
+  platform_is_not :windows do # https://bugs.ruby-lang.org/issues/12436
+    it "writes lf when IO is opened with newline: :lf" do
+      File.open(@name, 'wt', newline: :lf) do |file|
+        file.puts
       end
+      File.binread(@name).should == "\n"
     end
   end
 end
diff --git a/spec/ruby/core/io/read_spec.rb b/spec/ruby/core/io/read_spec.rb
index 6f6713d957..ccb341a1f9 100644
--- a/spec/ruby/core/io/read_spec.rb
+++ b/spec/ruby/core/io/read_spec.rb
@@ -95,16 +95,14 @@ describe "IO.read" do
     lambda { IO.read @fname, -1, -1 }.should raise_error(Errno::EINVAL)
   end
 
-  with_feature :encoding do
-    it "uses the external encoding specified via the :external_encoding option" do
-      str = IO.read(@fname, external_encoding: Encoding::ISO_8859_1)
-      str.encoding.should == Encoding::ISO_8859_1
-    end
+  it "uses the external encoding specified via the :external_encoding option" do
+    str = IO.read(@fname, external_encoding: Encoding::ISO_8859_1)
+    str.encoding.should == Encoding::ISO_8859_1
+  end
 
-    it "uses the external encoding specified via the :encoding option" do
-      str = IO.read(@fname, encoding: Encoding::ISO_8859_1)
-      str.encoding.should == Encoding::ISO_8859_1
-    end
+  it "uses the external encoding specified via the :encoding option" do
+    str = IO.read(@fname, encoding: Encoding::ISO_8859_1)
+    str.encoding.should == Encoding::ISO_8859_1
   end
 end
 
@@ -117,7 +115,7 @@ describe "IO.read from a pipe" do
     IO.read(cmd).should == "hello\n"
   end
 
-  with_feature :fork do
+  platform_is_not :windows do
     it "opens a pipe to a fork if the rest is -" do
       str = IO.read("|-")
       if str # parent
@@ -456,135 +454,133 @@ describe "IO.read with BOM" do
   end
 end
 
-with_feature :encoding do
-  describe :io_read_internal_encoding, shared: true do
-    it "returns a transcoded String" do
-      @io.read.should == "ありがとう\n"
+describe :io_read_internal_encoding, shared: true do
+  it "returns a transcoded String" do
+    @io.read.should == "ありがとう\n"
+  end
+
+  it "sets the String encoding to the internal encoding" do
+    @io.read.encoding.should equal(Encoding::UTF_8)
+  end
+
+  describe "when passed nil for limit" do
+    it "sets the buffer to a transcoded String" do
+      result = @io.read(nil, buf = "")
+      buf.should equal(result)
+      buf.should == "ありがとう\n"
     end
 
-    it "sets the String encoding to the internal encoding" do
-      @io.read.encoding.should equal(Encoding::UTF_8)
+    it "sets the buffer's encoding to the internal encoding" do
+      buf = "".force_encoding Encoding::ISO_8859_1
+      @io.read(nil, buf)
+      buf.encoding.should equal(Encoding::UTF_8)
     end
+  end
+end
 
-    describe "when passed nil for limit" do
-      it "sets the buffer to a transcoded String" do
-        result = @io.read(nil, buf = "")
-        buf.should equal(result)
-        buf.should == "ありがとう\n"
-      end
+describe :io_read_size_internal_encoding, shared: true do
+  it "reads bytes when passed a size" do
+    @io.read(2).should == [164, 162].pack('C*').force_encoding(Encoding::ASCII_8BIT)
+  end
 
-      it "sets the buffer's encoding to the internal encoding" do
-        buf = "".force_encoding Encoding::ISO_8859_1
-        @io.read(nil, buf)
-        buf.encoding.should equal(Encoding::UTF_8)
-      end
-    end
+  it "returns a String in ASCII-8BIT when passed a size" do
+    @io.read(4).encoding.should equal(Encoding::ASCII_8BIT)
   end
 
-  describe :io_read_size_internal_encoding, shared: true do
-    it "reads bytes when passed a size" do
-      @io.read(2).should == [164, 162].pack('C*').force_encoding(Encoding::ASCII_8BIT)
-    end
+  it "does not change the buffer's encoding when passed a limit" do
+    buf = "".force_encoding Encoding::ISO_8859_1
+    @io.read(4, buf)
+    buf.should == [164, 162, 164, 234].pack('C*').force_encoding(Encoding::ISO_8859_1)
+    buf.encoding.should equal(Encoding::ISO_8859_1)
+  end
 
-    it "returns a String in ASCII-8BIT when passed a size" do
-      @io.read(4).encoding.should equal(Encoding::ASCII_8BIT)
-    end
+  it "truncates the buffer but does not change the buffer's encoding when no data remains" do
+    buf = "abc".force_encoding Encoding::ISO_8859_1
+    @io.read
 
-    it "does not change the buffer's encoding when passed a limit" do
-      buf = "".force_encoding Encoding::ISO_8859_1
-      @io.read(4, buf)
-      buf.should == [164, 162, 164, 234].pack('C*').force_encoding(Encoding::ISO_8859_1)
-      buf.encoding.should equal(Encoding::ISO_8859_1)
+    @io.read(1, buf).should be_nil
+    buf.size.should == 0
+    buf.encoding.should equal(Encoding::ISO_8859_1)
+  end
+end
+
+describe "IO#read" do
+  describe "when IO#external_encoding and IO#internal_encoding are nil" do
+    before :each do
+      @name = tmp("io_read.txt")
+      touch(@name) { |f| f.write "\x00\x01\x02" }
+      @io = new_io @name, "r+"
     end
 
-    it "truncates the buffer but does not change the buffer's encoding when no data remains" do
-      buf = "abc".force_encoding Encoding::ISO_8859_1
-      @io.read
+    after :each do
+      @io.close if @io
+      rm_r @name
+    end
 
-      @io.read(1, buf).should be_nil
-      buf.size.should == 0
-      buf.encoding.should equal(Encoding::ISO_8859_1)
+    it "sets the String encoding to Encoding.default_external" do
+      @io.read.encoding.should equal(Encoding.default_external)
     end
   end
 
-  describe "IO#read" do
-    describe "when IO#external_encoding and IO#internal_encoding are nil" do
-      before :each do
-        @name = tmp("io_read.txt")
-        touch(@name) { |f| f.write "\x00\x01\x02" }
-        @io = new_io @name, "r+"
-      end
+  describe "with internal encoding" do
+    after :each do
+      @io.close if @io
+    end
 
-      after :each do
-        @io.close if @io
-        rm_r @name
+    describe "not specified" do
+      before :each do
+        @io = IOSpecs.io_fixture "read_euc_jp.txt", "r:euc-jp"
       end
 
-      it "sets the String encoding to Encoding.default_external" do
-        @io.read.encoding.should equal(Encoding.default_external)
+      it "does not transcode the String" do
+        @io.read.should == ("ありがとう\n").encode(Encoding::EUC_JP)
       end
-    end
 
-    describe "with internal encoding" do
-      after :each do
-        @io.close if @io
+      it "sets the String encoding to the external encoding" do
+        @io.read.encoding.should equal(Encoding::EUC_JP)
       end
 
-      describe "not specified" do
-        before :each do
-          @io = IOSpecs.io_fixture "read_euc_jp.txt", "r:euc-jp"
-        end
-
-        it "does not transcode the String" do
-          @io.read.should == ("ありがとう\n").encode(Encoding::EUC_JP)
-        end
-
-        it "sets the String encoding to the external encoding" do
-          @io.read.encoding.should equal(Encoding::EUC_JP)
-        end
+      it_behaves_like :io_read_size_internal_encoding, nil
+    end
 
-        it_behaves_like :io_read_size_internal_encoding, nil
+    describe "specified by open mode" do
+      before :each do
+        @io = IOSpecs.io_fixture "read_euc_jp.txt", "r:euc-jp:utf-8"
       end
 
-      describe "specified by open mode" do
-        before :each do
-          @io = IOSpecs.io_fixture "read_euc_jp.txt", "r:euc-jp:utf-8"
-        end
+      it_behaves_like :io_read_internal_encoding, nil
+      it_behaves_like :io_read_size_internal_encoding, nil
+    end
 
-        it_behaves_like :io_read_internal_encoding, nil
-        it_behaves_like :io_read_size_internal_encoding, nil
+    describe "specified by mode: option" do
+      before :each do
+        @io = IOSpecs.io_fixture "read_euc_jp.txt", mode: "r:euc-jp:utf-8"
       end
 
-      describe "specified by mode: option" do
-        before :each do
-          @io = IOSpecs.io_fixture "read_euc_jp.txt", mode: "r:euc-jp:utf-8"
-        end
+      it_behaves_like :io_read_internal_encoding, nil
+      it_behaves_like :io_read_size_internal_encoding, nil
+    end
 
-        it_behaves_like :io_read_internal_encoding, nil
-        it_behaves_like :io_read_size_internal_encoding, nil
+    describe "specified by internal_encoding: option" do
+      before :each do
+        options = { mode: "r",
+                    internal_encoding: "utf-8",
+                    external_encoding: "euc-jp" }
+        @io = IOSpecs.io_fixture "read_euc_jp.txt", options
       end
 
-      describe "specified by internal_encoding: option" do
-        before :each do
-          options = { mode: "r",
-                      internal_encoding: "utf-8",
-                      external_encoding: "euc-jp" }
-          @io = IOSpecs.io_fixture "read_euc_jp.txt", options
-        end
+      it_behaves_like :io_read_internal_encoding, nil
+      it_behaves_like :io_read_size_internal_encoding, nil
+    end
 
-        it_behaves_like :io_read_internal_encoding, nil
-        it_behaves_like :io_read_size_internal_encoding, nil
+    describe "specified by encoding: option" do
+      before :each do
+        options = { mode: "r", encoding: "euc-jp:utf-8" }
+        @io = IOSpecs.io_fixture "read_euc_jp.txt", options
       end
 
-      describe "specified by encoding: option" do
-        before :each do
-          options = { mode: "r", encoding: "euc-jp:utf-8" }
-          @io = IOSpecs.io_fixture "read_euc_jp.txt", options
-        end
-
-        it_behaves_like :io_read_internal_encoding, nil
-        it_behaves_like :io_read_size_internal_encoding, nil
-      end
+      it_behaves_like :io_read_internal_encoding, nil
+      it_behaves_like :io_read_size_internal_encoding, nil
     end
   end
 end
diff --git a/spec/ruby/core/io/readlines_spec.rb b/spec/ruby/core/io/readlines_spec.rb
index c1ea706b26..9e145f12f4 100644
--- a/spec/ruby/core/io/readlines_spec.rb
+++ b/spec/ruby/core/io/readlines_spec.rb
@@ -112,7 +112,7 @@ describe "IO#readlines" do
       lines.should == ["hello\n", "line2\n"]
     end
 
-    with_feature :fork do
+    platform_is_not :windows do
       it "gets data from a fork when passed -" do
         lines = IO.readlines("|-")
 
@@ -139,13 +139,13 @@ describe "IO#readlines" do
 
   it "raises an IOError if the stream is opened for append only" do
     lambda do
-      File.open(@name, fmode("a:utf-8")) { |f| f.readlines }
+      File.open(@name, "a:utf-8") { |f| f.readlines }
     end.should raise_error(IOError)
   end
 
   it "raises an IOError if the stream is opened for write only" do
     lambda do
-      File.open(@name, fmode("w:utf-8")) { |f| f.readlines }
+      File.open(@name, "w:utf-8") { |f| f.readlines }
     end.should raise_error(IOError)
   end
 end
diff --git a/spec/ruby/core/io/reopen_spec.rb b/spec/ruby/core/io/reopen_spec.rb
index 53fcc9dede..84c23472b7 100644
--- a/spec/ruby/core/io/reopen_spec.rb
+++ b/spec/ruby/core/io/reopen_spec.rb
@@ -145,23 +145,6 @@ describe "IO#reopen with a String" do
     File.read(@other_name).should == "new data"
   end
 
-  # File descriptor numbers are not predictable in multi-threaded code;
-  # MJIT will be opening/closing files the background
-  without_feature :mjit do
-    it "closes the file descriptor obtained by opening the new file" do
-      @io = new_io @name, "w"
-
-      @other_io = File.open @other_name, "w"
-      max = @other_io.fileno
-      @other_io.close
-
-      @io.reopen @other_name
-
-      @other_io = File.open @other_name, "w"
-      @other_io.fileno.should == max
-    end
-  end
-
   it "always resets the close-on-exec flag to true on non-STDIO objects" do
     @io = new_io @name, "w"
 
diff --git a/spec/ruby/core/io/set_encoding_spec.rb b/spec/ruby/core/io/set_encoding_spec.rb
index 9875d64ab8..a9d783325c 100644
--- a/spec/ruby/core/io/set_encoding_spec.rb
+++ b/spec/ruby/core/io/set_encoding_spec.rb
@@ -1,193 +1,191 @@
 require_relative '../../spec_helper'
 
-with_feature :encoding do
-  describe :io_set_encoding_write, shared: true do
-    it "sets the encodings to nil" do
-      @io = new_io @name, "#{@object}:ibm437:ibm866"
-      @io.set_encoding nil, nil
+describe :io_set_encoding_write, shared: true do
+  it "sets the encodings to nil" do
+    @io = new_io @name, "#{@object}:ibm437:ibm866"
+    @io.set_encoding nil, nil
 
-      @io.external_encoding.should be_nil
-      @io.internal_encoding.should be_nil
-    end
+    @io.external_encoding.should be_nil
+    @io.internal_encoding.should be_nil
+  end
 
-    it "prevents the encodings from changing when Encoding defaults are changed" do
-      @io = new_io @name, "#{@object}:utf-8:us-ascii"
-      @io.set_encoding nil, nil
+  it "prevents the encodings from changing when Encoding defaults are changed" do
+    @io = new_io @name, "#{@object}:utf-8:us-ascii"
+    @io.set_encoding nil, nil
 
-      Encoding.default_external = Encoding::IBM437
-      Encoding.default_internal = Encoding::IBM866
+    Encoding.default_external = Encoding::IBM437
+    Encoding.default_internal = Encoding::IBM866
 
-      @io.external_encoding.should be_nil
-      @io.internal_encoding.should be_nil
-    end
+    @io.external_encoding.should be_nil
+    @io.internal_encoding.should be_nil
+  end
 
-    it "sets the encodings to the current Encoding defaults" do
-      @io = new_io @name, @object
+  it "sets the encodings to the current Encoding defaults" do
+    @io = new_io @name, @object
 
-      Encoding.default_external = Encoding::IBM437
-      Encoding.default_internal = Encoding::IBM866
+    Encoding.default_external = Encoding::IBM437
+    Encoding.default_internal = Encoding::IBM866
 
-      @io.set_encoding nil, nil
+    @io.set_encoding nil, nil
 
-      @io.external_encoding.should == Encoding::IBM437
-      @io.internal_encoding.should == Encoding::IBM866
-    end
+    @io.external_encoding.should == Encoding::IBM437
+    @io.internal_encoding.should == Encoding::IBM866
   end
+end
 
-  describe "IO#set_encoding when passed nil, nil" do
-    before :each do
-      @external = Encoding.default_external
-      @internal = Encoding.default_internal
+describe "IO#set_encoding when passed nil, nil" do
+  before :each do
+    @external = Encoding.default_external
+    @internal = Encoding.default_internal
 
-      Encoding.default_external = Encoding::UTF_8
-      Encoding.default_internal = nil
+    Encoding.default_external = Encoding::UTF_8
+    Encoding.default_internal = nil
 
-      @name = tmp('io_set_encoding.txt')
-      touch(@name)
-    end
+    @name = tmp('io_set_encoding.txt')
+    touch(@name)
+  end
 
-    after :each do
-      Encoding.default_external = @external
-      Encoding.default_internal = @internal
+  after :each do
+    Encoding.default_external = @external
+    Encoding.default_internal = @internal
 
-      @io.close if @io and not @io.closed?
-      rm_r @name
-    end
+    @io.close if @io and not @io.closed?
+    rm_r @name
+  end
 
-    describe "with 'r' mode" do
-      it "sets the encodings to the current Encoding defaults" do
-        @io = new_io @name, "r"
+  describe "with 'r' mode" do
+    it "sets the encodings to the current Encoding defaults" do
+      @io = new_io @name, "r"
 
-        Encoding.default_external = Encoding::IBM437
-        Encoding.default_internal = Encoding::IBM866
+      Encoding.default_external = Encoding::IBM437
+      Encoding.default_internal = Encoding::IBM866
 
-        @io.set_encoding nil, nil
-        @io.external_encoding.should equal(Encoding::IBM437)
-        @io.internal_encoding.should equal(Encoding::IBM866)
-      end
+      @io.set_encoding nil, nil
+      @io.external_encoding.should equal(Encoding::IBM437)
+      @io.internal_encoding.should equal(Encoding::IBM866)
+    end
 
-      it "prevents the #internal_encoding from changing when Encoding.default_internal is changed" do
-        @io = new_io @name, "r"
-        @io.set_encoding nil, nil
+    it "prevents the #internal_encoding from changing when Encoding.default_internal is changed" do
+      @io = new_io @name, "r"
+      @io.set_encoding nil, nil
 
-        Encoding.default_internal = Encoding::IBM437
+      Encoding.default_internal = Encoding::IBM437
 
-        @io.internal_encoding.should be_nil
-      end
+      @io.internal_encoding.should be_nil
+    end
 
-      it "allows the #external_encoding to change when Encoding.default_external is changed" do
-        @io = new_io @name, "r"
-        @io.set_encoding nil, nil
+    it "allows the #external_encoding to change when Encoding.default_external is changed" do
+      @io = new_io @name, "r"
+      @io.set_encoding nil, nil
 
-        Encoding.default_external = Encoding::IBM437
+      Encoding.default_external = Encoding::IBM437
 
-        @io.external_encoding.should equal(Encoding::IBM437)
-      end
+      @io.external_encoding.should equal(Encoding::IBM437)
     end
+  end
 
-    describe "with 'rb' mode" do
-      it "returns Encoding.default_external" do
-        @io = new_io @name, "rb"
-        @io.external_encoding.should equal(Encoding::ASCII_8BIT)
+  describe "with 'rb' mode" do
+    it "returns Encoding.default_external" do
+      @io = new_io @name, "rb"
+      @io.external_encoding.should equal(Encoding::ASCII_8BIT)
 
-        @io.set_encoding nil, nil
-        @io.external_encoding.should equal(Encoding.default_external)
-      end
+      @io.set_encoding nil, nil
+      @io.external_encoding.should equal(Encoding.default_external)
     end
+  end
 
-    describe "with 'r+' mode" do
-      it_behaves_like :io_set_encoding_write, nil, "r+"
-    end
+  describe "with 'r+' mode" do
+    it_behaves_like :io_set_encoding_write, nil, "r+"
+  end
 
-    describe "with 'w' mode" do
-      it_behaves_like :io_set_encoding_write, nil, "w"
-    end
+  describe "with 'w' mode" do
+    it_behaves_like :io_set_encoding_write, nil, "w"
+  end
 
-    describe "with 'w+' mode" do
-      it_behaves_like :io_set_encoding_write, nil, "w+"
-    end
+  describe "with 'w+' mode" do
+    it_behaves_like :io_set_encoding_write, nil, "w+"
+  end
 
-    describe "with 'a' mode" do
-      it_behaves_like :io_set_encoding_write, nil, "a"
-    end
+  describe "with 'a' mode" do
+    it_behaves_like :io_set_encoding_write, nil, "a"
+  end
 
-    describe "with 'a+' mode" do
-      it_behaves_like :io_set_encoding_write, nil, "a+"
-    end
+  describe "with 'a+' mode" do
+    it_behaves_like :io_set_encoding_write, nil, "a+"
   end
+end
 
-  describe "IO#set_encoding" do
-    before :each do
-      @name = tmp('io_set_encoding.txt')
-      touch(@name)
-      @io = new_io @name
-    end
+describe "IO#set_encoding" do
+  before :each do
+    @name = tmp('io_set_encoding.txt')
+    touch(@name)
+    @io = new_io @name
+  end
 
-    after :each do
-      @io.close unless @io.closed?
-      rm_r @name
-    end
+  after :each do
+    @io.close unless @io.closed?
+    rm_r @name
+  end
 
-    it "returns self" do
-      @io.set_encoding(Encoding::UTF_8).should equal(@io)
-    end
+  it "returns self" do
+    @io.set_encoding(Encoding::UTF_8).should equal(@io)
+  end
 
-    it "sets the external encoding when passed an Encoding argument" do
-      @io.set_encoding(Encoding::UTF_8)
-      @io.external_encoding.should == Encoding::UTF_8
-      @io.internal_encoding.should be_nil
-    end
+  it "sets the external encoding when passed an Encoding argument" do
+    @io.set_encoding(Encoding::UTF_8)
+    @io.external_encoding.should == Encoding::UTF_8
+    @io.internal_encoding.should be_nil
+  end
 
-    it "sets the external and internal encoding when passed two Encoding arguments" do
-      @io.set_encoding(Encoding::UTF_8, Encoding::UTF_16BE)
-      @io.external_encoding.should == Encoding::UTF_8
-      @io.internal_encoding.should == Encoding::UTF_16BE
-    end
+  it "sets the external and internal encoding when passed two Encoding arguments" do
+    @io.set_encoding(Encoding::UTF_8, Encoding::UTF_16BE)
+    @io.external_encoding.should == Encoding::UTF_8
+    @io.internal_encoding.should == Encoding::UTF_16BE
+  end
 
-    it "sets the external encoding when passed the name of an Encoding" do
-      @io.set_encoding("utf-8")
-      @io.external_encoding.should == Encoding::UTF_8
-      @io.internal_encoding.should be_nil
-    end
+  it "sets the external encoding when passed the name of an Encoding" do
+    @io.set_encoding("utf-8")
+    @io.external_encoding.should == Encoding::UTF_8
+    @io.internal_encoding.should be_nil
+  end
 
-    it "ignores the internal encoding if the same as external when passed Encoding objects" do
-      @io.set_encoding(Encoding::UTF_8, Encoding::UTF_8)
-      @io.external_encoding.should == Encoding::UTF_8
-      @io.internal_encoding.should be_nil
-    end
+  it "ignores the internal encoding if the same as external when passed Encoding objects" do
+    @io.set_encoding(Encoding::UTF_8, Encoding::UTF_8)
+    @io.external_encoding.should == Encoding::UTF_8
+    @io.internal_encoding.should be_nil
+  end
 
-    it "ignores the internal encoding if the same as external when passed encoding names separated by ':'" do
-      @io.set_encoding("utf-8:utf-8")
-      @io.external_encoding.should == Encoding::UTF_8
-      @io.internal_encoding.should be_nil
-    end
+  it "ignores the internal encoding if the same as external when passed encoding names separated by ':'" do
+    @io.set_encoding("utf-8:utf-8")
+    @io.external_encoding.should == Encoding::UTF_8
+    @io.internal_encoding.should be_nil
+  end
 
-    it "sets the external and internal encoding when passed the names of Encodings separated by ':'" do
-      @io.set_encoding("utf-8:utf-16be")
-      @io.external_encoding.should == Encoding::UTF_8
-      @io.internal_encoding.should == Encoding::UTF_16BE
-    end
+  it "sets the external and internal encoding when passed the names of Encodings separated by ':'" do
+    @io.set_encoding("utf-8:utf-16be")
+    @io.external_encoding.should == Encoding::UTF_8
+    @io.internal_encoding.should == Encoding::UTF_16BE
+  end
 
-    it "sets the external and internal encoding when passed two String arguments" do
-      @io.set_encoding("utf-8", "utf-16be")
-      @io.external_encoding.should == Encoding::UTF_8
-      @io.internal_encoding.should == Encoding::UTF_16BE
-    end
+  it "sets the external and internal encoding when passed two String arguments" do
+    @io.set_encoding("utf-8", "utf-16be")
+    @io.external_encoding.should == Encoding::UTF_8
+    @io.internal_encoding.should == Encoding::UTF_16BE
+  end
 
-    it "calls #to_str to convert an abject to a String" do
-      obj = mock("io_set_encoding")
-      obj.should_receive(:to_str).and_return("utf-8:utf-16be")
-      @io.set_encoding(obj)
-      @io.external_encoding.should == Encoding::UTF_8
-      @io.internal_encoding.should == Encoding::UTF_16BE
-    end
+  it "calls #to_str to convert an abject to a String" do
+    obj = mock("io_set_encoding")
+    obj.should_receive(:to_str).and_return("utf-8:utf-16be")
+    @io.set_encoding(obj)
+    @io.external_encoding.should == Encoding::UTF_8
+    @io.internal_encoding.should == Encoding::UTF_16BE
+  end
 
-    it "calls #to_str to convert the second argument to a String" do
-      obj = mock("io_set_encoding")
-      obj.should_receive(:to_str).at_least(1).times.and_return("utf-16be")
-      @io.set_encoding(Encoding::UTF_8, obj)
-      @io.external_encoding.should == Encoding::UTF_8
-      @io.internal_encoding.should == Encoding::UTF_16BE
-    end
+  it "calls #to_str to convert the second argument to a String" do
+    obj = mock("io_set_encoding")
+    obj.should_receive(:to_str).at_least(1).times.and_return("utf-16be")
+    @io.set_encoding(Encoding::UTF_8, obj)
+    @io.external_encoding.should == Encoding::UTF_8
+    @io.internal_encoding.should == Encoding::UTF_16BE
   end
 end
diff --git a/spec/ruby/core/io/shared/write.rb b/spec/ruby/core/io/shared/write.rb
index 3cd4f8954e..aa6b3eedeb 100644
--- a/spec/ruby/core/io/shared/write.rb
+++ b/spec/ruby/core/io/shared/write.rb
@@ -85,7 +85,11 @@ describe :io_write, shared: true do
       @r.read.should == "foo"
     end
 
-    without_feature :mjit do # [ruby-core:90895] MJIT worker may leave fd open in a forked child. TODO: consider acquiring GVL from MJIT worker.
+    # [ruby-core:90895] MJIT worker may leave fd open in a forked child.
+    # For instance, MJIT creates a worker before @r.close with fork(), @r.close happens,
+    # and the MJIT worker keeps the pipe open until the worker execve().
+    # TODO: consider acquiring GVL from MJIT worker.
+    guard_not -> { defined?(RubyVM::MJIT) && RubyVM::MJIT.enabled? } do
       it "raises Errno::EPIPE if the read end is closed and does not die from SIGPIPE" do
         @r.close
         -> { @w.send(@method, "foo") }.should raise_error(Errno::EPIPE, /Broken pipe/)
diff --git a/spec/ruby/core/io/write_spec.rb b/spec/ruby/core/io/write_spec.rb
index 50e3df864d..5fb3941505 100644
--- a/spec/ruby/core/io/write_spec.rb
+++ b/spec/ruby/core/io/write_spec.rb
@@ -28,51 +28,49 @@ describe "IO#write on a file" do
     @file.write('').should == 0
   end
 
-  with_feature :encoding do
-    before :each do
-      @external = Encoding.default_external
-      @internal = Encoding.default_internal
+  before :each do
+    @external = Encoding.default_external
+    @internal = Encoding.default_internal
 
-      Encoding.default_external = Encoding::UTF_8
-    end
+    Encoding.default_external = Encoding::UTF_8
+  end
 
-    after :each do
-      Encoding.default_external = @external
-      Encoding.default_internal = @internal
-    end
+  after :each do
+    Encoding.default_external = @external
+    Encoding.default_internal = @internal
+  end
 
-    it "returns the number of bytes written" do
-      @file.write("hellø").should == 6
-    end
+  it "returns the number of bytes written" do
+    @file.write("hellø").should == 6
+  end
 
-    it "uses the encoding from the given option for non-ascii encoding" do
-      File.open(@filename, "w", encoding: Encoding::UTF_32LE) do |file|
-        file.write("hi").should == 8
-      end
-      File.binread(@filename).should == "h\u0000\u0000\u0000i\u0000\u0000\u0000"
+  it "uses the encoding from the given option for non-ascii encoding" do
+    File.open(@filename, "w", encoding: Encoding::UTF_32LE) do |file|
+      file.write("hi").should == 8
     end
+    File.binread(@filename).should == "h\u0000\u0000\u0000i\u0000\u0000\u0000"
+  end
 
-    it "uses an :open_args option" do
-      IO.write(@filename, 'hi', open_args: ["w", nil, {encoding: Encoding::UTF_32LE}]).should == 8
-    end
+  it "uses an :open_args option" do
+    IO.write(@filename, 'hi', open_args: ["w", nil, {encoding: Encoding::UTF_32LE}]).should == 8
+  end
 
-    it "raises a invalid byte sequence error if invalid bytes are being written" do
-      # pack "\xFEhi" to avoid utf-8 conflict
-      xFEhi = ([254].pack('C*') + 'hi').force_encoding('utf-8')
-      File.open(@filename, "w", encoding: Encoding::US_ASCII) do |file|
-        lambda { file.write(xFEhi) }.should raise_error(Encoding::InvalidByteSequenceError)
-      end
+  it "raises a invalid byte sequence error if invalid bytes are being written" do
+    # pack "\xFEhi" to avoid utf-8 conflict
+    xFEhi = ([254].pack('C*') + 'hi').force_encoding('utf-8')
+    File.open(@filename, "w", encoding: Encoding::US_ASCII) do |file|
+      lambda { file.write(xFEhi) }.should raise_error(Encoding::InvalidByteSequenceError)
     end
+  end
 
-    it "writes binary data if no encoding is given" do
-      File.open(@filename, "w") do |file|
-        file.write('Hëllö'.encode('ISO-8859-1'))
-      end
-      ë = ([235].pack('U')).encode('ISO-8859-1')
-      ö = ([246].pack('U')).encode('ISO-8859-1')
-      res = "H#{ë}ll#{ö}"
-      File.binread(@filename).should == res.force_encoding(Encoding::ASCII_8BIT)
+  it "writes binary data if no encoding is given" do
+    File.open(@filename, "w") do |file|
+      file.write('Hëllö'.encode('ISO-8859-1'))
     end
+    ë = ([235].pack('U')).encode('ISO-8859-1')
+    ö = ([246].pack('U')).encode('ISO-8859-1')
+    res = "H#{ë}ll#{ö}"
+    File.binread(@filename).should == res.force_encoding(Encoding::ASCII_8BIT)
   end
 end