1 files changed, 20 insertions, 24 deletions

diff --git a/actionpack/lib/action_controller/metal/strong_parameters.rb b/actionpack/lib/action_controller/metal/strong_parameters.rb
index 3f5e8c53a8..1f10fb3bbe 100644
--- a/actionpack/lib/action_controller/metal/strong_parameters.rb
+++ b/actionpack/lib/action_controller/metal/strong_parameters.rb
@@ -183,7 +183,7 @@ module ActionController
 
     # Returns an unsafe, unfiltered +Hash+ representation of this parameter.
     def to_unsafe_h
-      @parameters
+      @parameters.to_h
     end
     alias_method :to_unsafe_hash, :to_unsafe_h
 
@@ -566,20 +566,22 @@ module ActionController
       end
 
       def each_element(object)
-        if object.is_a?(Array)
-          object.map { |el| yield el }.compact
-        elsif fields_for_style?(object)
-          hash = object.class.new
-          object.each { |k,v| hash[k] = yield v }
-          hash
-        else
-          yield object
+        case object
+        when Array
+          object.grep(Parameters).map { |el| yield el }.compact
+        when Parameters
+          if fields_for_style?(object)
+            hash = object.class.new
+            object.each { |k,v| hash[k] = yield v }
+            hash
+          else
+            yield object
+          end
         end
       end
 
       def fields_for_style?(object)
-        (object.is_a?(Hash) || object.is_a?(Parameters)) &&
-          object.to_unsafe_h.all? { |k, v| k =~ /\A-?\d+\z/ && v.is_a?(Hash) }
+        object.to_unsafe_h.all? { |k, v| k =~ /\A-?\d+\z/ && v.is_a?(Hash) }
       end
 
       def unpermitted_parameters!(params)
@@ -643,14 +645,8 @@ module ActionController
       end
 
       def array_of_permitted_scalars?(value)
-        if value.is_a?(Array)
-          value.all? {|element| permitted_scalar?(element)}
-        end
-      end
-
-      def array_of_permitted_scalars_filter(params, key)
-        if has_key?(key) && array_of_permitted_scalars?(self[key])
-          params[key] = self[key]
+        if value.is_a?(Array) && value.all? {|element| permitted_scalar?(element)}
+          yield value
         end
       end
 
@@ -661,17 +657,17 @@ module ActionController
         # Slicing filters out non-declared keys.
         slice(*filter.keys).each do |key, value|
           next unless value
+          next unless has_key? key
 
           if filter[key] == EMPTY_ARRAY
             # Declaration { comment_ids: [] }.
-            array_of_permitted_scalars_filter(params, key)
+            array_of_permitted_scalars?(self[key]) do |val|
+              params[key] = val
+            end
           else
             # Declaration { user: :name } or { user: [:name, :age, { address: ... }] }.
             params[key] = each_element(value) do |element|
-              if element.is_a?(Hash) || element.is_a?(Parameters)
-                element = self.class.new(element) unless element.respond_to?(:permit)
-                element.permit(*Array.wrap(filter[key]))
-              end
+              element.permit(*Array.wrap(filter[key]))
             end
           end
         end