Allow blank but not nil in validations

- The most common use case for qualified_domain_validator currently is
to allow blank ([]) but not allow nil. Modify the
qualified_domain_validator to support this use case.

2 files changed, 7 insertions, 3 deletions

diff --git a/app/models/application_setting.rb b/app/models/application_setting.rb
index a769a8f07fd..9dbcef8abaa 100644
--- a/app/models/application_setting.rb
+++ b/app/models/application_setting.rb
@@ -42,9 +42,9 @@ class ApplicationSetting < ApplicationRecord
   validates :uuid, presence: true
 
   validates :outbound_local_requests_whitelist,
-            length: { maximum: 1_000, message: N_('is too long (maximum is 1000 entries)') }
-
-  validates :outbound_local_requests_whitelist, qualified_domain_array: true, allow_blank: true
+            length: { maximum: 1_000, message: N_('is too long (maximum is 1000 entries)') },
+            allow_nil: false,
+            qualified_domain_array: true
 
   validates :session_expire_delay,
             presence: true,
diff --git a/app/models/application_setting_implementation.rb b/app/models/application_setting_implementation.rb
index 1e612bd0e78..6efd07a6008 100644
--- a/app/models/application_setting_implementation.rb
+++ b/app/models/application_setting_implementation.rb
@@ -163,6 +163,8 @@ module ApplicationSettingImplementation
 
   def outbound_local_requests_whitelist_arrays
     strong_memoize(:outbound_local_requests_whitelist_arrays) do
+      next [[], []] unless self.outbound_local_requests_whitelist
+
       ip_whitelist = []
       domain_whitelist = []
 
@@ -284,6 +286,8 @@ module ApplicationSettingImplementation
   end
 
   def domain_strings_to_array(values)
+    return [] unless values
+
     values
       .split(DOMAIN_LIST_SEPARATOR)
       .reject(&:empty?)