FIX: Allow merging users when email domains are restricted

app/models/user.rb

@@ -1200,7 +1200,7 @@ class User < ActiveRecord::Base
     if primary_email
       new_record? ? primary_email.email = new_email : primary_email.update(email: new_email)
     else
-      self.primary_email = UserEmail.new(email: new_email, user: self, primary: true)
+      self.primary_email = UserEmail.new(email: new_email, user: self, primary: true, skip_validate_email: !should_validate_email_address?)
     end
   end
 

app/services/user_merger.rb

@@ -358,6 +358,8 @@ class UserMerger
 
   def delete_source_user
     @source_user.reload
+
+    @source_user.skip_email_validation = true
     @source_user.update(
       admin: false,
       email: "#{@source_user.username}_#{SecureRandom.hex}@no-email.invalid"

spec/services/user_merger_spec.rb

@@ -990,6 +990,15 @@ describe UserMerger do
     expect(User.find_by_username(source_user.username)).to be_nil
   end
 
+  it "works even when email domains are restricted" do
+    SiteSetting.email_domains_whitelist = "example.com|work.com"
+    source_user.update_attribute(:admin, true)
+
+    expect(User.find_by_username(source_user.username)).to be_present
+    merge_users!
+    expect(User.find_by_username(source_user.username)).to be_nil
+  end
+
   it "deletes external auth infos of source user" do
     UserAssociatedAccount.create(user_id: source_user.id, provider_name: "facebook", provider_uid: "1234")
     GithubUserInfo.create(user_id: source_user.id, screen_name: "example", github_user_id: "examplel123123")