`permit` do not work properly when value is array

[WaKeMaTTa]

Expected behaviour

Expected to return the permitted params.

params.require(:post).permit([:title, :body])

# Result:
{"title" => "My title", "body" => "My description"}

Actual behaviour

Instead of the expected behaviour i got an empty hash.

params.require(:post).permit([:title, :body])

# Result:
{}

Workarround

Adding * before array it works.

params.require(:post).permit(*[:title, :body])

# Result:
{"title" => "My title", "body" => "My description"}

System configuration

• Rails version: rails 3.2.22.5
• Ruby version: ruby 1.9.3p551
• strong_parameters version: strong_parameters 0.2.3