provisioners/salt: don't use exteranl deep_merge [GH-2348]

CHANGELOG.md

@@ -131,6 +131,8 @@ BUG FIXES:
     the newest versions of Docker. [GH-2874]
   - provisioners/puppet: Append default module path to the module paths
     always. [GH-2677]
+  - provisioners/salt: Setting pillar data doesn't require `deep_merge`
+    plugin anymore. [GH-2348]
   - provisioners/salt: Options can now set install type and install args.
     [GH-2766]
   - provisioners/salt: Fix case when salt would say "options only allowed

lib/vagrant/util/deep_merge.rb

@@ -0,0 +1,20 @@
+module Vagrant
+  module Util
+    module DeepMerge
+      # This was lifted straight from Rails 4.0.2 as a basic Hash
+      # deep merge.
+      def self.deep_merge(myself, other_hash, &block)
+        myself = myself.dup
+        other_hash.each_pair do |k,v|
+          tv = myself[k]
+          if tv.is_a?(Hash) && v.is_a?(Hash)
+            myself[k] = deep_merge(tv, v, &block)
+          else
+            myself[k] = block && tv ? block.call(k, tv, v) : v
+          end
+        end
+        myself
+      end
+    end
+  end
+end

plugins/provisioners/salt/config.rb

@@ -1,5 +1,5 @@
-require "i18n"
 require "vagrant"
+require "vagrant/util/deep_merge"
 
 module VagrantPlugins
   module Salt
@@ -78,7 +78,7 @@ module VagrantPlugins
 
       def pillar(data)
         @pillar_data = {} if @pillar_data == UNSET_VALUE
-        @pillar_data.deep_merge!(data)
+        @pillar_data = Vagrant::Util::DeepMerge.deep_merge(@pillar_data, data)
       end
 
       def validate(machine)

test/unit/vagrant/util/deep_merge_test.rb

@@ -0,0 +1,29 @@
+require File.expand_path("../../../base", __FILE__)
+
+require 'vagrant/util/deep_merge'
+
+describe Vagrant::Util::DeepMerge do
+  it "should deep merge hashes" do
+    original = {
+      "foo" => {
+        "bar" => "baz",
+      },
+      "bar" => "blah",
+    }
+
+    other = {
+      "foo" => {
+        "bar" => "new",
+      },
+    }
+
+    result = described_class.deep_merge(original, other)
+    expect(result).to_not equal(original)
+    expect(result).to eq({
+      "foo" => {
+        "bar" => "new",
+      },
+      "bar" => "blah",
+    })
+  end
+end