* lib/rubygems: Import RubyGems 2.1

* test/rubygems:  Ditto.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41873 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/rubygems/stub_specification.rb

@@ -0,0 +1,112 @@
+module Gem
+  # Gem::StubSpecification reads the stub: line from the gemspec
+  # This prevents us having to eval the entire gemspec in order to
+  # find out certain information.
+  class StubSpecification < BasicSpecification
+    # :nodoc:
+    PREFIX = "# stub: "
+
+    # :nodoc:
+    class StubLine
+      attr_reader :parts
+
+      def initialize(data)
+        @parts = data[PREFIX.length..-1].split(" ")
+      end
+
+      def name
+        @parts[0]
+      end
+
+      def version
+        Gem::Version.new @parts[1]
+      end
+
+      def platform
+        Gem::Platform.new @parts[2]
+      end
+
+      def require_paths
+        @parts[3..-1].join(" ").split("\0")
+      end
+    end
+
+    def initialize(filename)
+      self.filename = filename
+      @data         = nil
+      @spec         = nil
+    end
+
+    ##
+    # Name of the gem
+
+    def name
+      @name ||= data.name
+    end
+
+    ##
+    # Version of the gem
+
+    def version
+      @version ||= data.version
+    end
+
+    ##
+    # Platform of the gem
+
+    def platform
+      @platform ||= data.platform
+    end
+
+    ##
+    # Require paths of the gem
+
+    def require_paths
+      @require_paths ||= data.require_paths
+    end
+
+    ##
+    # The full Gem::Specification for this gem, loaded from evalling its gemspec
+
+    def to_spec
+      @spec ||= Gem::Specification.load(filename)
+    end
+
+    ##
+    # True when this gem has been activated
+
+    def activated?
+      loaded = Gem.loaded_specs[name]
+      loaded && loaded.version == version
+    end
+
+    ##
+    # Is this StubSpecification valid? i.e. have we found a stub line, OR does
+    # the filename contain a valid gemspec?
+
+    def valid?
+      data
+    end
+
+    private
+
+    ##
+    # If the gemspec contains a stubline, returns a StubLine instance. Otherwise
+    # returns the full Gem::Specification.
+
+    def data
+      unless @data
+        File.open(filename, "r:UTF-8:-") do |file|
+          begin
+            file.readline # discard encoding line
+            stubline = file.readline.chomp
+            @data = StubLine.new(stubline) if stubline.start_with?(PREFIX)
+          rescue EOFError
+          end
+        end
+      end
+
+      @data ||= to_spec
+    end
+  end
+end