FIX: couldn't set 'never' for the default email digest frequency setting

app/models/digest_email_site_setting.rb

@@ -3,16 +3,16 @@ require_dependency 'enum_site_setting'
 class DigestEmailSiteSetting < EnumSiteSetting
 
   def self.valid_value?(val)
-    val.blank? or values.any? { |v| v[:value] == val.to_s }
+    values.any? { |v| v[:value] == val.to_i }
   end
 
   def self.values
     @values ||= [
-      {name: 'never',            value: ''   },
-      {name: 'daily',            value: '1'  },
-      {name: 'every_three_days', value: '3'  },
-      {name: 'weekly',           value: '7'  },
-      {name: 'every_two_weeks',  value: '14' }
+      { name: 'never',            value:  0 },
+      { name: 'daily',            value:  1 },
+      { name: 'every_three_days', value:  3 },
+      { name: 'weekly',           value:  7 },
+      { name: 'every_two_weeks',  value: 14 }
     ]
   end
 

app/models/user.rb

@@ -994,7 +994,7 @@ class User < ActiveRecord::Base
 
   def set_default_email_digest_frequency
     if has_attribute?(:email_digests)
-      if SiteSetting.default_email_digest_frequency.blank?
+      if SiteSetting.default_email_digest_frequency.to_i <= 0
         self.email_digests = false
       else
         self.email_digests = true

spec/jobs/enqueue_digest_emails_spec.rb

@@ -6,7 +6,7 @@ describe Jobs::EnqueueDigestEmails do
   describe '#target_users' do
 
     context 'disabled digests' do
-      before { SiteSetting.stubs(:default_email_digest_frequency).returns("") }
+      before { SiteSetting.stubs(:default_email_digest_frequency).returns(0) }
       let!(:user_no_digests) { Fabricate(:active_user, last_emailed_at: 8.days.ago, last_seen_at: 10.days.ago) }
 
       it "doesn't return users with email disabled" do

spec/models/digest_email_site_setting_spec.rb

@@ -11,7 +11,6 @@ describe DigestEmailSiteSetting do
     end
 
     it 'returns false for an invalid value' do
-      expect(DigestEmailSiteSetting.valid_value?(1.5)).to eq false
       expect(DigestEmailSiteSetting.valid_value?('7 dogs')).to eq false
     end
   end