Revert "remove deprecated sis_login_id"

fixes CORE-589

This reverts commit 2137329872.

Change-Id: Ic3cba1fbf51bc21f4d1d26e07772b3db9bbb90cb
Reviewed-on: https://gerrit.instructure.com/131885
Tested-by: Jenkins
Reviewed-by: Cody Cutrer <cody@instructure.com>
Product-Review: Rob Orton <rob@instructure.com>
QA-Review: Rob Orton <rob@instructure.com>

lib/api/v1/user.rb

@@ -58,6 +58,10 @@ module Api::V1::User
         if user_can_read_sis_data?(current_user, context)
           json.merge! :sis_user_id => pseudonym&.sis_user_id,
                       :integration_id => pseudonym&.integration_id
+          # TODO: don't send sis_login_id; it's garbage data
+          if @domain_root_account.settings['return_sis_login_id'] == 'true'
+            json.merge! :sis_login_id => pseudonym&.unique_id
+          end
         end
         json[:sis_import_id] = pseudonym&.sis_batch_id if @domain_root_account.grants_right?(current_user, session, :manage_sis)
         json[:root_account] = HostUrl.context_host(pseudonym&.account) if include_root_account

spec/apis/v1/users_api_spec.rb

@@ -101,6 +101,24 @@ describe Api::V1::User do
         })
     end
 
+    it 'should return SIS login when setting is set' do
+      @user = User.create!(name: 'User')
+      Account.default.settings['return_sis_login_id'] = 'true'
+      Account.default.save!
+      @user.pseudonyms.create!(unique_id: 'xyz', account: Account.default) { |p| p.sis_user_id = 'xyz' }
+      expect(@test_api.user_json(@user, @admin, {}, [], Account.default)).to eq({
+          'name' => 'User',
+          'sortable_name' => 'User',
+          'sis_import_id' => nil,
+          'id' => @user.id,
+          'short_name' => 'User',
+          'sis_user_id' => 'xyz',
+          'integration_id' => nil,
+          'login_id' => 'xyz',
+          'sis_login_id' => 'xyz'
+        })
+    end
+
     it 'should show SIS data to sub account admins' do
       student = User.create!(:name => 'User')
       student.pseudonyms.create!(:unique_id => 'xyz', :account => Account.default) { |p| p.sis_user_id = 'xyz' }