backport fix for rails

lib/freedom_patches/join_dependency.rb

@@ -0,0 +1,22 @@
+# see PR: https://github.com/rails/rails/pull/12185
+#
+class ActiveRecord::Associations::JoinDependency::JoinPart
+
+  def extract_record(row)
+    # Used to be: Hash[column_names_with_alias.map{|cn, an| [cn, row[an]]}]
+    #  that is fairly inefficient cause all the values are first copied
+    #  in to an array only to construct the Hash
+    # This code is performance critical as it is called per row.
+    hash = {}
+
+    index = 0
+    while index < column_names_with_alias.length do
+      cn,an = column_names_with_alias[index]
+      hash[cn] = row[an]
+      index += 1
+    end
+
+    hash
+  end
+end
+