1 files changed, 85 insertions, 52 deletions

diff --git a/lib/rubygems/commands/update_command.rb b/lib/rubygems/commands/update_command.rb
index b2f69a5b52..b7c65eb2a4 100644
--- a/lib/rubygems/commands/update_command.rb
+++ b/lib/rubygems/commands/update_command.rb
@@ -27,8 +27,16 @@ class Gem::Commands::UpdateCommand < Gem::Command
 
     add_install_update_options
 
-    add_option('--system',
+    OptionParser.accept Gem::Version do |value|
+      Gem::Version.new value
+
+      value
+    end
+
+    add_option('--system [VERSION]', Gem::Version,
                'Update the RubyGems system software') do |value, options|
+      value = true unless value
+
       options[:system] = value
     end
 
@@ -50,33 +58,13 @@ class Gem::Commands::UpdateCommand < Gem::Command
   end
 
   def execute
+    @installer = Gem::DependencyInstaller.new options
+    @updated   = []
+
     hig = {}
 
     if options[:system] then
-      say "Updating RubyGems"
-
-      unless options[:args].empty? then
-        raise "No gem names are allowed with the --system option"
-      end
-
-      rubygems_update = Gem::Specification.new
-      rubygems_update.name = 'rubygems-update'
-      rubygems_update.version = Gem::Version.new Gem::VERSION
-      hig['rubygems-update'] = rubygems_update
-
-      options[:user_install] = false
-
-      Gem.source_index.refresh!
-
-      update_gems = Gem.source_index.find_name 'rubygems-update'
-
-      latest_update_gem = update_gems.sort_by { |s| s.version }.last
-
-      say "Updating RubyGems to #{latest_update_gem.version}"
-      installed = do_rubygems_update latest_update_gem.version
-
-      say "RubyGems system software updated" if installed
-
+      update_rubygems
       return
     else
       say "Updating installed gems"
@@ -92,28 +80,7 @@ class Gem::Commands::UpdateCommand < Gem::Command
 
     gems_to_update = which_to_update hig, options[:args]
 
-    updated = []
-
-    installer = Gem::DependencyInstaller.new options
-
-    gems_to_update.uniq.sort.each do |name|
-      next if updated.any? { |spec| spec.name == name }
-      success = false
-
-      say "Updating #{name}"
-      begin
-        installer.install name
-        success = true
-      rescue Gem::InstallError => e
-        alert_error "Error installing #{name}:\n\t#{e.message}"
-        success = false
-      end
-
-      installer.installed_gems.each do |spec|
-        updated << spec
-        say "Successfully installed #{spec.full_name}" if success
-      end
-    end
+    updated = update_gems gems_to_update
 
     if updated.empty? then
       say "Nothing to update"
@@ -136,12 +103,77 @@ class Gem::Commands::UpdateCommand < Gem::Command
     end
   end
 
+  def update_gem name, version = Gem::Requirement.default
+    return if @updated.any? { |spec| spec.name == name }
+    success = false
+
+    say "Updating #{name}"
+    begin
+      @installer.install name, version
+      success = true
+    rescue Gem::InstallError => e
+      alert_error "Error installing #{name}:\n\t#{e.message}"
+      success = false
+    end
+
+    @installer.installed_gems.each do |spec|
+      @updated << spec
+      say "Successfully installed #{spec.full_name}" if success
+    end
+  end
+
+  def update_gems gems_to_update
+    gems_to_update.uniq.sort.each do |name|
+      update_gem name
+    end
+
+    @updated
+  end
+
   ##
-  # Update the RubyGems software to +version+.
+  # Update RubyGems software to the latest version.
+
+  def update_rubygems
+    unless options[:args].empty? then
+      alert_error "Gem names are not allowed with the --system option"
+      terminate_interaction 1
+    end
+
+    options[:user_install] = false
+
+    version = options[:system]
+    if version == true then
+      version     = Gem::Version.new     Gem::VERSION
+      requirement = Gem::Requirement.new ">= #{Gem::VERSION}"
+    else
+      version     = Gem::Version.new     version
+      requirement = Gem::Requirement.new version
+    end
+
+    rubygems_update         = Gem::Specification.new
+    rubygems_update.name    = 'rubygems-update'
+    rubygems_update.version = version
+
+    hig = {
+      'rubygems-update' => rubygems_update
+    }
+
+    gems_to_update = which_to_update hig, options[:args]
+
+    if gems_to_update.empty? then
+      say "Latest version currently installed. Aborting."
+      terminate_interaction
+    end
+
+    update_gem gems_to_update.first, requirement
+
+    Gem.source_index.refresh!
+
+    installed_gems = Gem.source_index.find_name 'rubygems-update', requirement
+    version        = installed_gems.last.version
 
-  def do_rubygems_update(version)
     args = []
-    args.push '--prefix', Gem.prefix unless Gem.prefix.nil?
+    args << '--prefix' << Gem.prefix if Gem.prefix
     args << '--no-rdoc' unless options[:generate_rdoc]
     args << '--no-ri' unless options[:generate_ri]
     args << '--no-format-executable' if options[:no_format_executable]
@@ -154,8 +186,9 @@ class Gem::Commands::UpdateCommand < Gem::Command
 
       # Make sure old rubygems isn't loaded
       old = ENV["RUBYOPT"]
-      ENV.delete("RUBYOPT")
-      system setup_cmd
+      ENV.delete("RUBYOPT") if old
+      installed = system setup_cmd
+      say "RubyGems system software updated" if installed
       ENV["RUBYOPT"] = old if old
     end
   end