Add in-tree mspec and ruby/spec

* For easier modifications of ruby/spec by MRI developers.
* .gitignore: track changes under spec.
* spec/mspec, spec/rubyspec: add in-tree mspec and ruby/spec.
  These files can therefore be updated like any other file in MRI.
  Instructions are provided in spec/README.
  [Feature #13156] [ruby-core:79246]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58595 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

spec/rubyspec/library/socket/tcpsocket/gethostbyname_spec.rb

@@ -0,0 +1,51 @@
+require File.expand_path('../../../../spec_helper', __FILE__)
+require File.expand_path('../../fixtures/classes', __FILE__)
+
+# TODO: verify these for windows
+describe "TCPSocket#gethostbyname" do
+  before :each do
+    @host_info = TCPSocket.gethostbyname(SocketSpecs.hostname)
+  end
+
+  it "returns an array elements of information on the hostname" do
+    @host_info.should be_kind_of(Array)
+  end
+
+  platform_is_not :windows do
+    it "returns the canonical name as first value" do
+      @host_info[0].should == SocketSpecs.hostname
+    end
+
+    it "returns the address type as the third value" do
+      address_type = @host_info[2]
+      [Socket::AF_INET, Socket::AF_INET6].include?(address_type).should be_true
+    end
+
+    it "returns the IP address as the fourth value" do
+      ip = @host_info[3]
+      ["127.0.0.1", "::1"].include?(ip).should be_true
+    end
+  end
+
+  platform_is :windows do
+    quarantine! do # name lookup seems not working on Windows CI
+      it "returns the canonical name as first value" do
+        host = "#{ENV['COMPUTERNAME'].downcase}"
+        host << ".#{ENV['USERDNSDOMAIN'].downcase}" if ENV['USERDNSDOMAIN']
+        @host_info[0].should == host
+      end
+    end
+
+    it "returns the address type as the third value" do
+      @host_info[2].should == Socket::AF_INET
+    end
+
+    it "returns the IP address as the fourth value" do
+      @host_info[3].should == "127.0.0.1"
+    end
+  end
+
+  it "returns any aliases to the address as second value" do
+    @host_info[1].should be_kind_of(Array)
+  end
+end