Better checking of blacklisted emails on create and when email is being updated

app/models/user.rb

@@ -27,7 +27,7 @@ class User < ActiveRecord::Base
   validates_presence_of :email
   validates_uniqueness_of :email
   validate :username_validator
-  validate :email_validator
+  validate :email_validator, :if => :email_changed?
   validate :password_validator
 
   before_save :cook
@@ -506,7 +506,7 @@ class User < ActiveRecord::Base
     end
 
     def email_validator
-      if new_record? and (setting = SiteSetting.email_domains_blacklist).present?
+      if (setting = SiteSetting.email_domains_blacklist).present?
         domains = setting.gsub('.', '\.')
         regexp = Regexp.new("@(#{domains})", true)
         if self.email =~ regexp

spec/models/user_spec.rb

@@ -484,6 +484,13 @@ describe User do
       SiteSetting.stubs(:email_domains_blacklist).returns('fakemail.com')
       u.should be_valid
     end
+
+    it 'should be used when email is being changed' do
+      SiteSetting.stubs(:email_domains_blacklist).returns('mailinator.com')
+      u = Fabricate(:user, email: 'good@gmail.com')
+      u.email = 'nope@mailinator.com'
+      u.should_not be_valid
+    end
   end
 
   describe 'passwords' do