2 files changed, 2 insertions, 5 deletions
diff --git a/actionpack/lib/action_dispatch/request/session.rb b/actionpack/lib/action_dispatch/request/session.rb
index 973627f106..9a1a05e971 100644
--- a/actionpack/lib/action_dispatch/request/session.rb
+++ b/actionpack/lib/action_dispatch/request/session.rb
@@ -9,7 +9,8 @@ module ActionDispatch
 
       # Singleton object used to determine if an optional param wasn't specified
       Unspecified = Object.new
-
+      
+      # Creates a session hash, merging the properties of the previous session if any
       def self.create(store, env, default_options)
         session_was = find env
         session     = Request::Session.new(store, env)
diff --git a/actionpack/lib/action_dispatch/request/utils.rb b/actionpack/lib/action_dispatch/request/utils.rb
index 9d4f1aa3c5..1c9371d89c 100644
--- a/actionpack/lib/action_dispatch/request/utils.rb
+++ b/actionpack/lib/action_dispatch/request/utils.rb
@@ -16,10 +16,6 @@ module ActionDispatch
             when Array
               v.grep(Hash) { |x| deep_munge(x, keys) }
               v.compact!
-              if v.empty?
-                hash[k] = nil
-                ActiveSupport::Notifications.instrument("deep_munge.action_controller", keys: keys)
-              end
             when Hash
               deep_munge(v, keys)
             end