Isolate #try_dup.

lib/dm-core/associations/relationship.rb

@@ -451,8 +451,8 @@ def initialize(name, child_model, parent_model, options = {})
         @options                = options.dup.freeze
         @child_repository_name  = @options[:child_repository_name]
         @parent_repository_name = @options[:parent_repository_name]
-        @child_properties       = @options[:child_key].try_dup.freeze
-        @parent_properties      = @options[:parent_key].try_dup.freeze
+        @child_properties       = DataMapper::Ext.try_dup(@options[:child_key]).freeze
+        @parent_properties      = DataMapper::Ext.try_dup(@options[:parent_key]).freeze
         @min                    = @options[:min]
         @max                    = @options[:max]
         @reader_visibility      = @options.fetch(:reader_visibility, :public)

lib/dm-core/ext/try_dup.rb

@@ -0,0 +1,12 @@
+module DataMapper
+  module Ext
+    def self.try_dup(value)
+      case value
+      when ::TrueClass, ::FalseClass, ::NilClass, ::Module, ::Numeric, ::Symbol
+        value
+      else
+        value.dup
+      end
+    end
+  end
+end

lib/dm-core/query.rb

@@ -363,7 +363,7 @@ def update(other)
       assert_valid_options(@options)
 
       normalize = DataMapper::Ext::Hash.only(other_options, *OPTIONS - [ :conditions ]).map do |attribute, value|
-        instance_variable_set("@#{attribute}", value.try_dup)
+        instance_variable_set("@#{attribute}", DataMapper::Ext.try_dup(value))
         attribute
       end
 
@@ -748,7 +748,7 @@ def initialize_copy(*)
       @fields     = @fields.dup
       @links      = @links.dup
       @conditions = @conditions.dup
-      @order      = @order.try_dup
+      @order      = DataMapper::Ext.try_dup(@order)
     end
 
     # Validate the options

lib/dm-core/resource.rb

@@ -752,7 +752,7 @@ def initialize(attributes = nil) # :nodoc:
     # @api private
     def initialize_copy(original)
       instance_variables.each do |ivar|
-        instance_variable_set(ivar, instance_variable_get(ivar).try_dup)
+        instance_variable_set(ivar, DataMapper::Ext.try_dup(instance_variable_get(ivar)))
       end
 
       self.persisted_state = persisted_state.class.new(self)

lib/dm-core/support/lazy_array.rb

@@ -1,4 +1,4 @@
-require 'dm-core/core_ext/try_dup'
+require 'dm-core/ext/try_dup'
 
 class LazyArray  # borrowed partially from StrokeDB
   include Enumerable
@@ -358,9 +358,9 @@ def initialize
   end
 
   def initialize_copy(original)
-    @head  = @head.try_dup
-    @tail  = @tail.try_dup
-    @array = @array.try_dup
+    @head  = DataMapper::Ext.try_dup(@head)
+    @tail  = DataMapper::Ext.try_dup(@tail)
+    @array = DataMapper::Ext.try_dup(@array)
   end
 
   def lazy_load

lib/dm-core/support/subject.rb

@@ -16,7 +16,7 @@ def default_for(resource)
       if @default.respond_to?(:call)
         @default.call(resource, self)
       else
-        @default.try_dup
+        DataMapper::Ext.try_dup(@default)
       end
     end
 

spec/support/core_ext/inheritable_attributes.rb

@@ -9,7 +9,7 @@ def self.#{ivar}
           return nil      if self.object_id == #{self.object_id}
           ivar = superclass.#{ivar}
           return nil if ivar.nil?
-          @#{ivar} = ivar.try_dup
+          @#{ivar} = DataMapper::Ext.try_dup(ivar)
         end
       RUBY
 

spec/unit/try_dup_spec.rb

@@ -1,46 +1,46 @@
 require 'spec_helper'
-require 'dm-core/core_ext/try_dup'
+require 'dm-core/ext/try_dup'
 
 describe "try_dup" do
   it "returns a duplicate version on regular objects" do
     obj = Object.new
-    oth = obj.try_dup
+    oth = DataMapper::Ext.try_dup(obj)
     obj.should_not === oth
   end
 
   it "returns self on Numerics" do
     obj = 12
-    oth = obj.try_dup
+    oth = DataMapper::Ext.try_dup(obj)
     obj.should === oth
   end
 
   it "returns self on Symbols" do
     obj = :test
-    oth = obj.try_dup
+    oth = DataMapper::Ext.try_dup(obj)
     obj.should === oth
   end
 
   it "returns self on true" do
     obj = true
-    oth = obj.try_dup
+    oth = DataMapper::Ext.try_dup(obj)
     obj.should === oth
   end
 
   it "returns self on false" do
     obj = false
-    oth = obj.try_dup
+    oth = DataMapper::Ext.try_dup(obj)
     obj.should === oth
   end
 
   it "returns self on nil" do
     obj = nil
-    oth = obj.try_dup
+    oth = DataMapper::Ext.try_dup(obj)
     obj.should === oth
   end
 
   it "returns self on modules" do
     obj = Module.new
-    oth = obj.try_dup
+    oth = DataMapper::Ext.try_dup(obj)
     obj.object_id.should == oth.object_id
   end
 end