2 files changed, 10 insertions, 1 deletions
diff --git a/actionpack/lib/action_controller/metal/exceptions.rb b/actionpack/lib/action_controller/metal/exceptions.rb
index 3c9d0c86a7..3844dbf2a6 100644
--- a/actionpack/lib/action_controller/metal/exceptions.rb
+++ b/actionpack/lib/action_controller/metal/exceptions.rb
@@ -3,6 +3,15 @@ module ActionController
   end
 
   class BadRequest < ActionControllerError #:nodoc:
+    attr_reader :original_exception
+
+    def initialize(type = nil, e = nil)
+      return super() unless type && e
+
+      super("Invalid #{type} parameters: #{e.message}")
+      @original_exception = e
+      set_backtrace e.backtrace
+    end
   end
 
   class RenderError < ActionControllerError #:nodoc:
diff --git a/actionpack/lib/action_controller/metal/strong_parameters.rb b/actionpack/lib/action_controller/metal/strong_parameters.rb
index 73f2e94cd1..04dc1d37f7 100644
--- a/actionpack/lib/action_controller/metal/strong_parameters.rb
+++ b/actionpack/lib/action_controller/metal/strong_parameters.rb
@@ -196,7 +196,7 @@ module ActionController
     def permit(*filters)
       params = self.class.new
 
-      filters.each do |filter|
+      filters.flatten.each do |filter|
         case filter
         when Symbol, String then
           if has_key?(filter)