2 files changed, 8 insertions, 8 deletions
diff --git a/activemodel/lib/active_model/mass_assignment_security/permission_set.rb b/activemodel/lib/active_model/mass_assignment_security/permission_set.rb
index 9661349503..f104d0306c 100644
--- a/activemodel/lib/active_model/mass_assignment_security/permission_set.rb
+++ b/activemodel/lib/active_model/mass_assignment_security/permission_set.rb
@@ -2,10 +2,10 @@ require 'set'
 
 module ActiveModel
   module MassAssignmentSecurity
-    class PermissionSet < Set
+    class PermissionSet < Set #:nodoc:
 
       def +(values)
-        super(values.map(&:to_s))
+        super(values.compact.map(&:to_s))
       end
 
       def include?(key)
@@ -23,14 +23,14 @@ module ActiveModel
       end
     end
 
-    class WhiteList < PermissionSet
+    class WhiteList < PermissionSet #:nodoc:
 
       def deny?(key)
         !include?(key)
       end
     end
 
-    class BlackList < PermissionSet
+    class BlackList < PermissionSet #:nodoc:
 
       def deny?(key)
         include?(key)
diff --git a/activemodel/lib/active_model/mass_assignment_security/sanitizer.rb b/activemodel/lib/active_model/mass_assignment_security/sanitizer.rb
index 44ce5a489d..dafb7cdff3 100644
--- a/activemodel/lib/active_model/mass_assignment_security/sanitizer.rb
+++ b/activemodel/lib/active_model/mass_assignment_security/sanitizer.rb
@@ -1,6 +1,6 @@
 module ActiveModel
   module MassAssignmentSecurity
-    class Sanitizer
+    class Sanitizer #:nodoc:
       # Returns all attributes not denied by the authorizer.
       def sanitize(klass, attributes, authorizer)
         rejected = []
@@ -18,7 +18,7 @@ module ActiveModel
       end
     end
 
-    class LoggerSanitizer < Sanitizer
+    class LoggerSanitizer < Sanitizer #:nodoc:
       def initialize(target)
         @target = target
         super()
@@ -50,7 +50,7 @@ module ActiveModel
       end
     end
 
-    class StrictSanitizer < Sanitizer
+    class StrictSanitizer < Sanitizer #:nodoc:
       def initialize(target = nil)
         super()
       end
@@ -65,7 +65,7 @@ module ActiveModel
       end
     end
 
-    class Error < StandardError
+    class Error < StandardError #:nodoc:
       def initialize(klass, attrs)
         super("Can't mass-assign protected attributes for #{klass.name}: #{attrs.join(', ')}")
       end