Merge pull request #1734 from madlep/fix_dict_behaviour_equals

`Dict.size` incorrectly returning `true` when left dict is subset of right dict

Author: José Valim

lib/elixir/lib/dict/behaviour.ex

@@ -99,7 +99,7 @@ defmodule Dict.Behaviour do
       defoverridable values: 1
 
       def equal?(dict1, dict2) do
-        case size(dict1) == size(dict2) do
+        case Dict.size(dict1) == Dict.size(dict2) do
           false -> false
           true -> 
             try do
@@ -122,4 +122,4 @@ defmodule Dict.Behaviour do
       defoverridable merge: 2, merge: 3
     end
   end
-end
+end

lib/elixir/test/elixir/dict_test.exs

@@ -214,6 +214,10 @@ defmodule DictTest.Common do
 
         dict2 = Dict.put(dict2, :a, 3)
         refute Dict.equal?(dict1, dict2)
+
+        dict3 = HashDict.new(a: 2, b: 3, f: 5, c: 123, z: 666)
+        refute Dict.equal?(dict1, dict3)
+        refute Dict.equal?(dict3, dict1)
       end
 
       test "unsupported dict" do