From 01cf25055226c74394f08ca356011ef520c662f1 Mon Sep 17 00:00:00 2001
From: Aaron Patterson <aaron.patterson@gmail.com>
Date: Sun, 10 Jun 2012 22:44:54 -0500
Subject: [PATCH] Array parameters should not contain nil values.

---
 actionpack/lib/action_dispatch/http/request.rb     |    6 ++++--
 .../dispatch/request/query_string_parsing_test.rb  |    4 ++++
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/actionpack/lib/action_dispatch/http/request.rb b/actionpack/lib/action_dispatch/http/request.rb
index 985b730..04b4a21 100644
--- a/actionpack/lib/action_dispatch/http/request.rb
+++ b/actionpack/lib/action_dispatch/http/request.rb
@@ -262,17 +262,19 @@ module ActionDispatch
 
     # Remove nils from the params hash
     def deep_munge(hash)
+      keys = hash.keys.find_all { |k| hash[k] == [nil] }
+      keys.each { |k| hash[k] = nil }
+
       hash.each_value do |v|
         case v
         when Array
           v.grep(Hash) { |x| deep_munge(x) }
+          v.compact!
         when Hash
           deep_munge(v)
         end
       end
 
-      keys = hash.keys.find_all { |k| hash[k] == [nil] }
-      keys.each { |k| hash[k] = nil }
       hash
     end
 
diff --git a/actionpack/test/dispatch/request/query_string_parsing_test.rb b/actionpack/test/dispatch/request/query_string_parsing_test.rb
index c7ab700..8ea14df 100644
--- a/actionpack/test/dispatch/request/query_string_parsing_test.rb
+++ b/actionpack/test/dispatch/request/query_string_parsing_test.rb
@@ -89,6 +89,10 @@ class QueryStringParsingTest < ActionController::IntegrationTest
     assert_parses({"action"=>{"foo"=>[{"bar"=>nil}]}}, "action[foo][][bar]")
   end
 
+  def test_array_parses_without_nil
+    assert_parses({"action" => ['1']}, "action[]=1&action[]")
+  end
+
   test "query string with empty key" do
     assert_parses(
       { "action" => "create_customer", "full_name" => "David Heinemeier Hansson" },
-- 
1.7.5.4