Config loader no longer assumes latest version for procs.

Previously, all procs were assumed to just be the current version. This
is certainly not going to be true always so now the version number of
the configuration must be explicit if you're assigning a proc to the
configuration loader.

lib/vagrant/config/loader.rb

@@ -114,30 +114,42 @@ module Vagrant
       # the configuration object and are expected to mutate this
       # configuration object.
       def procs_for_source(source)
-        # If the source is just a proc, we assume it is for the latest
-        # version of the configuration. This may be an ill assumption,
-        # but it made building the initial version of multi-versioned
-        # configuration easy to support the old sub-VM stuff.
-        return [[@version_order.last, source]] if source.is_a?(Proc)
+        # Convert all pathnames to strings so we just have their path
+        source = source.to_s if source.is_a?(Pathname)
 
-        # Assume all string sources are actually pathnames
-        source = Pathname.new(source) if source.is_a?(String)
+        if source.is_a?(Array)
+          # An array must be formatted as [version, proc], so verify
+          # that and then return it
+          raise ArgumentError, "String source must have format [version, proc]" if source.length != 2
 
-        if source.is_a?(Pathname)
-          @logger.debug("Load procs for pathname: #{source.inspect}")
+          # Return it as an array since we're expected to return an array
+          # of [version, proc] pairs, but an array source only has one.
+          return [source]
+        elsif source.is_a?(String)
+          # Strings are considered paths, so load them
+          return procs_for_path(source)
+        else
+          raise ArgumentError, "Unknown configuration source: #{source.inspect}"
+        end
+      end
+
+      # This returns an array of `Proc` objects for the given path source.
+      #
+      # @param [String] path Path to the file which contains the proper
+      #   `Vagrant.configure` calls.
+      # @return [Array<Proc>]
+      def procs_for_path(path)
+        @logger.debug("Load procs for pathname: #{path}")
 
         begin
           return Config.capture_configures do
-              Kernel.load source
+            Kernel.load path
           end
         rescue SyntaxError => e
           # Report syntax errors in a nice way.
           raise Errors::VagrantfileSyntaxError, :file => e.message
         end
        end
-
-        raise Exception, "Unknown configuration source: #{source.inspect}"
-      end
     end
   end
 end

lib/vagrant/environment.rb

@@ -395,7 +395,7 @@ module Vagrant
 
         if subvm
           # We have subvm configuration, so set that up as well.
-          config_loader.set(:vm, subvm.proc_stack)
+          config_loader.set(:vm, subvm.config_procs)
         end
 
         # We activate plugins here because the files which we're loading

plugins/kernel_v1/config/vm_subvm.rb

@@ -11,6 +11,16 @@ module VagrantPlugins
       def initialize
         @options = {}
       end
+
+      # This returns an array of the procs to configure this VM, with
+      # the proper version pre-pended for the configuration loader.
+      #
+      # @return [Array]
+      def config_procs
+        proc_stack.map do |proc|
+          ["1", proc]
+        end
+      end
     end
   end
 end

test/unit/vagrant/config/loader_test.rb

@@ -5,6 +5,9 @@ require "vagrant/registry"
 describe Vagrant::Config::Loader do
   include_context "unit"
 
+  # This is the current version of configuration for the tests.
+  let(:current_version) { version_order.last }
+
   # This is just a dummy implementation of a configuraiton loader which
   # simply acts on hashes.
   let(:test_loader) do
@@ -46,7 +49,7 @@ describe Vagrant::Config::Loader do
     end
 
     instance.load_order = [:proc]
-    instance.set(:proc, proc)
+    instance.set(:proc, [[current_version, proc]])
     config = instance.load
 
     config[:foo].should == "yep"
@@ -60,7 +63,7 @@ describe Vagrant::Config::Loader do
     end
 
     instance.load_order = [:proc]
-    instance.set(:proc, proc)
+    instance.set(:proc, [[current_version, proc]])
 
     5.times do
       result = instance.load