FIX: update `email_digests` user option when `default_email_digest_frequency` updated.

app/controllers/admin/site_settings_controller.rb

@@ -37,12 +37,10 @@ class Admin::SiteSettingsController < Admin::AdminController
           new_value = UserOption.title_count_modes[new_value.to_sym]
         end
 
-        UserOption.where(user_option => previous_value).update_all(user_option => new_value)
+        attrs = { user_option => new_value }
+        attrs[:email_digests] = (new_value.to_i != 0) if id == "default_email_digest_frequency"
 
-        if id == "default_email_digest_frequency"
-          disable_digests = new_value == 0
-          UserOption.where(user_option => 0, email_digests: !disable_digests).update_all(email_digests: disable_digests)
-        end
+        UserOption.where(user_option => previous_value).update_all(attrs)
       elsif id.start_with?("default_categories_")
         previous_category_ids = previous_value.split("|")
         new_category_ids = new_value.split("|")

spec/requests/admin/site_settings_controller_spec.rb

@@ -77,7 +77,16 @@ describe Admin::SiteSettingsController do
           }.to change { UserOption.where(email_in_reply_to: false).count }.by(0)
         end
 
-        it 'should disable email digests in existing user options' do
+        it 'should update `email_digests` column in existing user options' do
+          UserOption.last.update(email_digests: false)
+
+          expect {
+            put "/admin/site_settings/default_email_digest_frequency.json", params: {
+              default_email_digest_frequency: 30,
+              updateExistingUsers: true
+            }
+          }.to change { UserOption.where(email_digests: true).count }.by(1)
+
           expect {
             put "/admin/site_settings/default_email_digest_frequency.json", params: {
               default_email_digest_frequency: 0,