Load plugins with the private gem path.

This changed plugin loading semantics a tiny bit, since they are
no longer loaded when Vagrant is loaded but instead when the
Vagrant::Environment is initialized. I'll note this in the CHANGELOG.

lib/vagrant.rb

@@ -50,6 +50,9 @@ require 'i18n'
 # there are issues with ciphers not being properly loaded.
 require 'openssl'
 
+# Always make the version available
+require 'vagrant/version'
+
 module Vagrant
   autoload :Action,        'vagrant/action'
   autoload :Box,           'vagrant/box'
@@ -186,7 +189,3 @@ Vagrant.provisioners.register(:shell)         { Vagrant::Provisioners::Shell }
 Vagrant.config_keys.register(:freebsd) { Vagrant::Guest::FreeBSD::FreeBSDConfig }
 Vagrant.config_keys.register(:linux)   { Vagrant::Guest::Linux::LinuxConfig }
 Vagrant.config_keys.register(:solaris) { Vagrant::Guest::Solaris::SolarisConfig }
-
-# Load the things which must be loaded before anything else.
-require 'vagrant/version'
-Vagrant::Plugin.load!

lib/vagrant/environment.rb

@@ -88,6 +88,9 @@ module Vagrant
       # Setup the default private key
       @default_private_key_path = @home_path.join("insecure_private_key")
       copy_insecure_private_key
+
+      # Load the plugins
+      load_plugins
     end
 
     #---------------------------------------------------------------
@@ -494,5 +497,17 @@ module Vagrant
 
       nil
     end
+
+    # Loads the Vagrant plugins by properly setting up RubyGems so that
+    # our private gem repository is on the path.
+    def load_plugins
+      # Add our private gem path to the gem path and reset the paths
+      # that Rubygems knows about.
+      ENV["GEM_PATH"] = "#{@gems_path}:#{ENV["GEM_PATH"]}"
+      ::Gem.clear_paths
+
+      # Load the plugins
+      Plugin.load!
+    end
   end
 end

lib/vagrant/plugin.rb

@@ -9,15 +9,9 @@ module Vagrant
   # (for debugging), the list of loaded plugins is stored in the {plugins}
   # array.
   class Plugin
-    # The array of loaded plugins.
+    # The array of gem specifications that were loaded as plugins.
     @@plugins = []
 
-    # The gemspec of this plugin. This is an actual gemspec object.
-    attr_reader :gemspec
-
-    # The path to the `vagrant_init.rb` file which was loaded for this plugin.
-    attr_reader :file
-
     # Loads all the plugins for Vagrant. Plugins are currently
     # gems which have a "vagrant_init.rb" somewhere on their
     # load path. This file is loaded to kick off the load sequence
@@ -46,6 +40,11 @@ module Vagrant
         specs = Gem::VERSION >= "1.6.0" ? source.latest_specs(true) : source.latest_specs
 
         specs.each do |spec|
+          if @@plugins.include?(spec)
+            logger.debug("Plugin already loaded, not loading again: #{spec.name}")
+            next
+          end
+
           # If this gem depends on Vagrant, verify this is a valid release of
           # Vagrant for this gem to load into.
           vagrant_dep = spec.dependencies.find { |d| d.name == "vagrant" }
@@ -65,7 +64,8 @@ module Vagrant
           next if !file
 
           logger.info("Loading plugin: #{spec.name} (#{spec.version})")
-          @@plugins << new(spec, file)
+          @@plugins << spec
+          load file
         end
 
         logger.info("Loaded #{@@plugins.length} plugins.")
@@ -77,15 +77,5 @@ module Vagrant
     #
     # @return [Array]
     def self.plugins; @@plugins; end
-
-    # Initializes a new plugin, given a Gemspec and the path to the
-    # gem's `vagrant_init.rb` file. This should never be called manually.
-    # Instead {load!} creates all the instances.
-    def initialize(spec, file)
-      @gemspec = spec
-      @file = file
-
-      load file
-    end
   end
 end