Master variants are valid without unit value or description

app/models/spree/variant_decorator.rb

@@ -1,7 +1,9 @@
 Spree::Variant.class_eval do
   validates_presence_of :unit_value,
-                        if: -> v { %w(weight volume).include? v.product.variant_unit }
+                        if: -> v { %w(weight volume).include? v.product.variant_unit },
+                        unless: :is_master
 
   validates_presence_of :unit_description,
-                        if: -> v { v.product.variant_unit.present? && v.unit_value.nil? }
+                        if: -> v { v.product.variant_unit.present? && v.unit_value.nil? },
+                        unless: :is_master
 end

spec/models/spree/product_spec.rb

@@ -29,7 +29,7 @@ module Spree
         let(:product) do
           product = create(:simple_product)
           create(:variant, product: product)
-          product
+          product.reload
         end
 
         it "requires a unit" do

spec/models/spree/variant_spec.rb

@@ -10,6 +10,7 @@ module Spree
         context "when the product's unit is #{unit}" do
           before do
             product.update_attribute :variant_unit, unit
+            product.reload
           end
 
           it "is valid when unit value is set and unit description is not" do
@@ -22,12 +23,17 @@ module Spree
             variant.unit_value = nil
             variant.should_not be_valid
           end
+
+          it "has a valid master variant" do
+            product.master.should be_valid
+          end
         end
       end
 
       context "when the product's unit is items" do
         before do
           product.update_attribute :variant_unit, 'items'
+          product.reload
         end
 
         it "is valid with only unit value set" do
@@ -47,6 +53,10 @@ module Spree
           variant.unit_description = nil
           variant.should_not be_valid
         end
+
+        it "has a valid master variant" do
+          product.master.should be_valid
+        end
       end
     end