Revert the check for duplicate Vagrantfiles.

This is just tricky with case sensitive/insensitive file systems.
Reverting since it doesn't seem worth it.

lib/vagrant/environment.rb

@@ -478,32 +478,15 @@ module Vagrant
 
     # Finds the Vagrantfile in the given directory.
     #
-    # This will raise an error if multiple matching Vagrantfiles are found.
-    # This can only occur on case sensitive file systems, but if there is a
-    # `Vagrantfile` and a `vagrantfile` it is not clear which Vagrant will
-    # load, so an error must be raised.
-    #
     # @param [Pathname] path Path to search in.
     # @return [Pathname]
     def find_vagrantfile(search_path)
-      path = nil
       @vagrantfile_name.each do |vagrantfile|
         current_path = search_path.join(vagrantfile)
-
-        # If the path exists, then we verify we haven't found a match before,
-        # then we set the path we've found.
-        if current_path.exist?
-          # We also test if current_path == path because on case insensitive
-          # file systems, it will look like multiple exist.
-          if path && current_path != path
-            raise Errors::MultiVagrantfileFound, :directory => search_path.to_s
-          end
-
-          path = current_path
-        end
+        return current_path if current_path.exist?
       end
 
-      path
+      nil
     end
   end
 end

lib/vagrant/errors.rb

@@ -193,11 +193,6 @@ module Vagrant
       error_key(:port_collision_resume)
     end
 
-    class MultiVagrantfileFound < VagrantError
-      status_code(67)
-      error_key(:multi_vagrantfile_found)
-    end
-
     class MultiVMEnvironmentRequired < VagrantError
       status_code(5)
       error_key(:multi_vm_required)

lib/vagrant/util/platform.rb

@@ -1,4 +1,5 @@
 require 'rbconfig'
+require 'tempfile'
 
 module Vagrant
   module Util

templates/locales/en.yml

@@ -64,14 +64,8 @@ en:
         directory that Vagrant uses must be both readable and writable.
 
         You specified: %{home_path}
-      interrupted: "Vagrant exited after cleanup due to external interrupt."
-      multi_vagrantfile_found: |-
-        Multiple Vagrantfiles were found in the following directory. This usually
-        occurs when multiple Vagrantfiles with different casing are found. For
-        example: Vagrantfile and vagrantfile. Because the behavior in this case
-        is undefined, please fix it so that there is only one matching Vagrantfile.
-
-        %{directory}
+      interrupted: |-
+        Vagrant exited after cleanup due to external interrupt.
       multi_vm_required: |-
         A multi-vm environment is required for name specification to this command.
       multi_vm_target_required: |-

test/unit/vagrant/environment_test.rb

@@ -151,26 +151,6 @@ VF
       env = environment.create_vagrant_env
       env.config.for_vm(:default).ssh.port.should == 100
     end
-
-    it "should error if the box has an ambiguous Vagrantfile" do
-      environment = isolated_environment do |env|
-        env.vagrantfile(<<-VF)
-Vagrant::Config.run do |config|
-  config.vm.box = "base"
-end
-VF
-
-        # Create two Vagrantfiles. The normal one and a Vagrantfile2
-        box_dir = env.box("base", "")
-        box_dir.join("Vagrantfile2").open("w") do |f|
-          f.write("")
-        end
-      end
-
-      env = environment.create_vagrant_env(:vagrantfile_name => ["Vagrantfile", "Vagrantfile2"])
-      expect { env.config }.
-        to raise_error(Vagrant::Errors::MultiVagrantfileFound)
-    end
   end
 
   describe "ui" do