WeakHash is not used, remove it.

activesupport/lib/active_support/weak_hash.rb

@@ -1,41 +0,0 @@
-module ActiveSupport
-  if defined?(RUBY_ENGINE) && RUBY_ENGINE == 'jruby'
-    WeakHash = ::Weakling::WeakHash
-  else
-    class WeakHash
-      def initialize(cache = Hash.new)
-        @cache = cache
-        @key_map = {}
-        @rev_cache = Hash.new{|h,k| h[k] = {}}
-        @reclaim_value = lambda do |value_id|
-          if value = @rev_cache.delete(value_id)
-            value.each_key{|key| @cache.delete key}
-          end
-        end
-      end
-
-      def [](key)
-        value_id = @cache[key]
-        value_id && ObjectSpace._id2ref(value_id)
-      rescue RangeError
-        nil
-      end
-
-      def []=(key, value)
-        @rev_cache[value.object_id][key] = true
-        @cache[key] = value.object_id
-        @key_map[key.object_id] = key
-
-        ObjectSpace.define_finalizer(value, @reclaim_value)
-      end
-
-      def clear
-        @cache.clear
-      end
-
-      def delete(key)
-        @cache.delete(key)
-      end
-    end
-  end
-end

activesupport/test/weak_hash_test.rb

@@ -1,33 +0,0 @@
-require 'abstract_unit'
-require 'active_support/weak_hash'
-
-class WeakHashTest < ActiveSupport::TestCase
-
-  def setup
-    @weak_hash = ActiveSupport::WeakHash.new
-    @str = "A";
-    @obj = Object.new
-  end
-
-  test "allows us to assign value, and return assigned value" do
-    a = @str; b = @obj
-    assert_equal @weak_hash[a] = b, b
-  end
-
-  test "should allow us to assign and read value" do
-    a = @str; b = @obj
-    assert_equal @weak_hash[a] = b, b
-    assert_equal @weak_hash[a], b
-  end
-
-  test "should use object_id to identify objects" do
-    a = Object.new
-    @weak_hash[a] = "b"
-    assert_nil @weak_hash[a.dup]
-  end
-
-  test "should find objects that have same hash" do
-    @weak_hash["a"] = "b"
-    assert_equal "b", @weak_hash["a"]
-  end
-end