MONGOID-5841 don't auto-build if the parent is frozen

Author: jamis

lib/mongoid/association/accessors.rb

@@ -304,7 +304,7 @@ def self.define_getter!(association)
         association.inverse_class.tap do |klass|
           klass.re_define_method(name) do |reload = false|
             value = get_relation(name, association, nil, reload)
-            if value.nil? && association.autobuilding? && !without_autobuild?
+            if !frozen? && value.nil? && association.autobuilding? && !without_autobuild?
               value = send("build_#{name}")
             end
             value

spec/mongoid/association/accessors_spec.rb

@@ -5,7 +5,7 @@
 
 describe Mongoid::Association::Accessors do
 
-  describe "\#{getter}?" do
+  describe '#{getter}?' do
 
     let(:person) do
       Person.create!
@@ -242,7 +242,7 @@
     end
   end
 
-  describe "\#{getter}" do
+  describe '#{getter}' do
 
     let(:person) do
       Person.new
@@ -267,6 +267,16 @@
           end
         end
 
+        context 'when the parent is frozen' do
+          before do
+            person.freeze
+          end
+
+          it 'returns nil' do
+            expect(person.passport).to be_nil
+          end
+        end
+
         context "when the association exists" do
 
           let!(:passport) do