Add protection against recycled objects being found instead of intend…

…ed result array

lib/optimizations/columns/macro.rb

@@ -76,7 +76,7 @@ def find_by_sql_with_scrooge( sql )
             callsite_set = scrooge_callsite(callsite_signature).columns
             sql = sql.gsub(scrooge_select_regex, "SELECT #{scrooge_select_sql(callsite_set)} FROM")
             results = connection.select_all(sanitize_sql(sql), "#{name} Load Scrooged")
-            result_set = []
+            result_set = ResultSets::ResultArray.new
             updateable = ResultSets::UpdateableResultSet.new(result_set, self)
             results.inject(result_set) do |memo, record|
               memo << instantiate(ScroogedAttributes.setup(record, callsite_set, self, callsite_signature, updateable))

lib/optimizations/result_sets/result_array.rb

@@ -0,0 +1,9 @@
+module Scrooge
+  module Optimizations
+    module ResultSets
+      class ResultArray < Array
+        attr_accessor :unique_id
+      end
+    end
+  end
+end

lib/optimizations/result_sets/updateable_result_set.rb

@@ -3,13 +3,16 @@ module Optimizations
     module ResultSets
       class UpdateableResultSet
 
-        # Contains weak referernce to result set, and can update from DB
+        # Contains a weak referernce to the result set, and can update from DB
         #
 
         attr_accessor :updaters_attributes
 
         def initialize(result_set_array, klass)
-          @result_set_object_id = result_set_array.object_id if result_set_array.is_a?(Array)
+          if result_set_array
+            @result_set_object_id = result_set_array.object_id
+            @unique_id = result_set_array.unique_id ||= "#{Time.now.to_f}#{object_id}"  # avoid recycled object ids
+          end
           @klass = klass  # expected class of items in the array
         end
 
@@ -27,19 +30,22 @@ def reload_columns_for_ids(columns_to_fetch, result_ids_to_fetch)
         end
 
         def result_set_attributes
-          if @result_set_object_id
-            result_set = ObjectSpace._id2ref(@result_set_object_id)
-            result_set.inject(default_attributes) do |memo, r|
-              if r.is_a?(@klass)
-                memo |= [r.instance_variable_get(:@attributes)]
-              end
-              memo
+          rs = result_set
+          return default_attributes unless rs
+          rs.inject(default_attributes) do |memo, r|
+            if r.is_a?(@klass)
+              memo |= [r.instance_variable_get(:@attributes)]
             end
-          else
-            default_attributes
+            memo
           end
+        end
+
+        def result_set
+          return nil unless @result_set_object_id
+          result_set = ObjectSpace._id2ref(@result_set_object_id)
+          result_set.is_a?(ResultArray) && result_set.unique_id == @unique_id ? result_set : nil
         rescue RangeError
-          default_attributes
+          nil
         end
 
         def default_attributes
@@ -68,7 +74,8 @@ def update_with(remaining_attributes)
 
         def primary_key_name
           @klass.primary_key
-        end      
+        end
+
       end
     end
   end

lib/scrooge.rb

@@ -5,6 +5,7 @@
 require 'optimizations/columns/attributes_proxy'
 require 'optimizations/columns/macro'
 require 'optimizations/result_sets/updateable_result_set'
+require 'optimizations/result_sets/result_array'
 
 module ActiveRecord
   class Base