Remove the dotfile (.vagrant) if no more active VMs exist

lib/vagrant/environment.rb

@@ -305,10 +305,7 @@ module Vagrant
     # Persists this environment's VM to the dotfile so it can be
     # re-loaded at a later time.
     def update_dotfile
-      if parent
-        parent.update_dotfile
-        return
-      end
+      return parent.update_dotfile if parent
 
       # Generate and save the persisted VM info
       data = vms.inject({}) do |acc, data|
@@ -317,9 +314,13 @@ module Vagrant
         acc
       end
 
+      if data.empty?
+        File.rm(dotfile_path)
+      else
         File.open(dotfile_path, 'w+') do |f|
           f.write(data.to_json)
         end
+      end
 
       # Also add to the global store
       # active_list.add(vm)

test/vagrant/environment_test.rb

@@ -733,6 +733,16 @@ class EnvironmentTest < Test::Unit::TestCase
       @env.update_dotfile
     end
 
+    should "remove the dotfile if the data is empty" do
+      vms = {
+        :foo => create_vm(false)
+      }
+
+      @env.stubs(:vms).returns(vms)
+      File.expects(:rm).with(@env.dotfile_path).once
+      @env.update_dotfile
+    end
+
     should "write the proper data to dotfile" do
       vms = {
         :foo => create_vm(false),