Raise ActionController::BadRequest for malformed parameter hashes.

Currently Rack raises a TypeError when it encounters a malformed or
ambiguous hash like `foo[]=bar&foo[4]=bar`. Rather than pass this
through to the application this commit captures the exception and
re-raises it using a new ActionController::BadRequest exception.

The new ActionController::BadRequest exception returns a 400 error
instead of the 500 error that would've been returned by the original
TypeError. This allows exception notification libraries to ignore
these errors if so desired.

Closes #3051

1 files changed, 4 insertions, 1 deletions

diff --git a/actionpack/lib/action_controller/metal/exceptions.rb b/actionpack/lib/action_controller/metal/exceptions.rb
index 90648c37ad..8fd8f4797c 100644
--- a/actionpack/lib/action_controller/metal/exceptions.rb
+++ b/actionpack/lib/action_controller/metal/exceptions.rb
@@ -2,6 +2,9 @@ module ActionController
   class ActionControllerError < StandardError #:nodoc:
   end
 
+  class BadRequest < ActionControllerError #:nodoc:
+  end
+
   class RenderError < ActionControllerError #:nodoc:
   end
 
@@ -38,7 +41,7 @@ module ActionController
 
   class UnknownHttpMethod < ActionControllerError #:nodoc:
   end
-  
+
   class UnknownFormat < ActionControllerError #:nodoc:
   end
 end