Config clearing.

lib/vagrant/config.rb

@@ -8,6 +8,11 @@ module Vagrant
     @config_runners = []
 
     class << self
+      def reset!
+        @config = nil
+        config_runners.clear
+      end
+
       def config
         @config ||= Config::Top.new
       end

lib/vagrant/env.rb

@@ -38,7 +38,8 @@ module Vagrant
           load path if File.exist?(path)
         end
 
-        # Execute the configurations
+        # Execute the configurations, clearing out the old data
+        Config.reset!
         Config.execute!
       end
 

test/vagrant/config_test.rb

@@ -1,6 +1,30 @@
 require File.join(File.dirname(__FILE__), '..', 'test_helper')
 
 class ConfigTest < Test::Unit::TestCase
+  context "resetting" do
+    setup do
+      Vagrant::Config.run { |config| }
+      Vagrant::Config.execute!
+    end
+
+    should "return the same config object typically" do
+      config = Vagrant::Config.config
+      assert config.equal?(Vagrant::Config.config)
+    end
+
+    should "create a new object if cleared" do
+      config = Vagrant::Config.config
+      Vagrant::Config.reset!
+      assert !config.equal?(Vagrant::Config.config)
+    end
+
+    should "empty the runners" do
+      assert !Vagrant::Config.config_runners.empty?
+      Vagrant::Config.reset!
+      assert Vagrant::Config.config_runners.empty?
+    end
+  end
+
   context "accessing configuration" do
     setup do
       Vagrant::Config.run { |config| }

test/vagrant/env_test.rb

@@ -59,6 +59,12 @@ class EnvTest < Test::Unit::TestCase
       Vagrant::Env.stubs(:root_path).returns(@root_path)
       File.stubs(:exist?).returns(false)
       Vagrant::Config.stubs(:execute!)
+      Vagrant::Config.stubs(:reset!)
+    end
+
+    should "reset the configuration object" do
+      Vagrant::Config.expects(:reset!).once
+      Vagrant::Env.load_config!
     end
 
     should "load from the project root" do