Ability to skip email validation via a plugin

app/models/user.rb

@@ -73,7 +73,7 @@ class User < ActiveRecord::Base
   validates_presence_of :username
   validate :username_validator, if: :username_changed?
   validates :email, presence: true, uniqueness: true
-  validates :email, email: true, if: Proc.new { |u| !u.staged && u.email_changed? }
+  validates :email, email: true, if: :should_validate_email?
   validate :password_validator
   validates :name, user_full_name: true, if: :name_changed?
   validates :ip_address, allowed_ip_address: {on: :create, message: :signup_not_allowed}
@@ -102,6 +102,9 @@ class User < ActiveRecord::Base
     TopicViewItem.delete_all(user_id: self.id)
   end
 
+  # Skip validating email, for example from a particular auth provider plugin
+  attr_accessor :skip_email_validation
+
   # Whether we need to be sending a system message after creation
   attr_accessor :send_welcome_message
 
@@ -247,6 +250,10 @@ class User < ActiveRecord::Base
     used_invite.try(:invited_by)
   end
 
+  def should_validate_email?
+    return !skip_email_validation && !staged? && email_changed?
+  end
+
   # Approve this user
   def approve(approved_by, send_mail=true)
     self.approved = true