Array parameters should not contain nil values.

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 6757a53bd1..65ff6fb7d8 100644
--- a/actionpack/lib/action_dispatch/http/request.rb
+++ b/actionpack/lib/action_dispatch/http/request.rb
@@ -267,17 +267,19 @@ 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 6ea66f9d32..bf7cb9914c 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 < ActionDispatch::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" },