Concatenation changes default value in model

[alexeyramazanov]

Rails 3.2.3 Ruby 1.9.3.125
Example shows the problem:

create_table "settings" do |t|
  t.string   "param", :null => false
  t.text     "value", :null => false
  t.datetime "created_at"
  t.datetime "updated_at"
end

> Setting.column_defaults
 => {"id"=>nil, "param"=>nil, "value"=>"", "created_at"=>nil, "updated_at"=>nil}
> Setting.new    
 => #<Setting id: nil, param: nil, value: "", created_at: nil, updated_at: nil> 
> s = Setting.new
 => #<Setting id: nil, param: nil, value: "", created_at: nil, updated_at: nil> 
> s.value << "text" # MAGIC STARTS HERE
 => "text" 
> s
 => #<Setting id: nil, param: nil, value: "text", created_at: nil, updated_at: nil> 
> Setting.new
 => #<Setting id: nil, param: nil, value: "text", created_at: nil, updated_at: nil>
> Setting.column_defaults
 => {"id"=>nil, "param"=>nil, "value"=>"text", "created_at"=>nil, "updated_at"=>nil} 

[pixeltrix]

@tenderlove @jonleighton should we freeze the hash?