VM#invoke_callback now returns an array of the results of the actions which implemented the callback.

lib/vagrant/actions/base.rb

@@ -7,6 +7,7 @@ module Vagrant
     class Base
       attr_reader :vm
 
+      # Included so subclasses don't need to include it themselves.
       include Vagrant::Util
 
       # Initialization of the actions are done all at once. The guarantee

lib/vagrant/vm.rb

@@ -45,9 +45,12 @@ module Vagrant
     def invoke_callback(name, *args)
       # Attempt to call the method for the callback on each of the
       # actions
+      results = []
       @actions.each do |action|
-        action.send(name, *args) if action.respond_to?(name)
+        results << action.send(name, *args) if action.respond_to?(name)
       end
+
+      results
     end
 
     def create

test/vagrant/vm_test.rb

@@ -34,6 +34,19 @@ class VMTest < Test::Unit::TestCase
       @vm.actions << action
       @vm.invoke_callback(:foo)
     end
+
+    should "collect all the results and return them as an array" do
+      result = []
+      3.times do |i|
+        action = mock("action#{i}")
+        action.expects(:foo).returns("foo#{i}").once
+
+        @vm.actions << action
+        result << "foo#{i}"
+      end
+
+      assert_equal result, @vm.invoke_callback(:foo)
+    end
   end
 
   context "actions" do