Convert :primary_key in association to a string before comparing to column names, so that for example :primary_key => :another_pk works as well [#5605 state:resolved]

activerecord/lib/active_record/association_preload.rb

@@ -320,7 +320,7 @@ module ActiveRecord
           klass = klass_name.constantize
 
           table_name = klass.quoted_table_name
-          primary_key = reflection.options[:primary_key] || klass.primary_key
+          primary_key = (reflection.options[:primary_key] || klass.primary_key).to_s
           column_type = klass.columns.detect{|c| c.name == primary_key}.type
 
           ids = _id_map.keys.map do |id|

activerecord/test/cases/associations/belongs_to_associations_test.rb

@@ -81,6 +81,13 @@ class BelongsToAssociationsTest < ActiveRecord::TestCase
     assert_not_nil citibank_result.instance_variable_get("@firm_with_primary_key")
   end
 
+  def test_eager_loading_with_primary_key_as_symbol
+    Firm.create("name" => "Apple")
+    Client.create("name" => "Citibank", :firm_name => "Apple")
+    citibank_result = Client.find(:first, :conditions => {:name => "Citibank"}, :include => :firm_with_primary_key_symbols)
+    assert_not_nil citibank_result.instance_variable_get("@firm_with_primary_key_symbols")
+  end
+
   def test_no_unexpected_aliasing
     first_firm = companies(:first_firm)
     another_firm = companies(:another_firm)

activerecord/test/models/company.rb

@@ -107,6 +107,7 @@ class Client < Company
   belongs_to :firm_with_other_name, :class_name => "Firm", :foreign_key => "client_of"
   belongs_to :firm_with_condition, :class_name => "Firm", :foreign_key => "client_of", :conditions => ["1 = ?", 1]
   belongs_to :firm_with_primary_key, :class_name => "Firm", :primary_key => "name", :foreign_key => "firm_name"
+  belongs_to :firm_with_primary_key_symbols, :class_name => "Firm", :primary_key => :name, :foreign_key => :firm_name
   belongs_to :readonly_firm, :class_name => "Firm", :foreign_key => "firm_id", :readonly => true
 
   # Record destruction so we can test whether firm.clients.clear has