Remove the functionality introduce in 28d3390

There are several situations it doesn't cater for, and the inconsistency isn't worth blocking 2.2.

activerecord/lib/active_record/associations.rb

@@ -1235,7 +1235,7 @@ def association_accessor_methods(reflection, association_proxy_class)
 
             association = instance_variable_get(ivar) if instance_variable_defined?(ivar)
 
-            if association.nil? || !association.loaded? || force_reload
+            if association.nil? || force_reload
               association = association_proxy_class.new(self, reflection)
               retval = association.reload
               if retval.nil? and association_proxy_class == BelongsToAssociation
@@ -1269,17 +1269,6 @@ def association_accessor_methods(reflection, association_proxy_class)
             end
           end
 
-          if association_proxy_class == BelongsToAssociation
-            define_method("#{reflection.primary_key_name}=") do |target_id|
-              if instance_variable_defined?(ivar)
-                if association = instance_variable_get(ivar)
-                  association.reset
-                end
-              end
-              write_attribute(reflection.primary_key_name, target_id)
-            end
-          end
-
           define_method("set_#{reflection.name}_target") do |target|
             return if target.nil? and association_proxy_class == BelongsToAssociation
             association = association_proxy_class.new(self, reflection)

activerecord/test/cases/associations/belongs_to_associations_test.rb

@@ -47,19 +47,6 @@ def test_natural_assignment
     assert_equal apple.id, citibank.firm_id
   end
 
-  def test_foreign_key_assignment
-    # Test using an existing record
-    signals37 = accounts(:signals37)
-    assert_equal companies(:first_firm), signals37.firm
-    signals37.firm_id = companies(:another_firm).id
-    assert_equal companies(:another_firm), signals37.firm
-
-    # Test using a new record
-    account = Account.new
-    account.firm_id = companies(:another_firm).id
-    assert_equal companies(:another_firm), account.firm
-  end
-
   def test_no_unexpected_aliasing
     first_firm = companies(:first_firm)
     another_firm = companies(:another_firm)

activerecord/test/cases/associations_test.rb

@@ -182,26 +182,6 @@ def test_failed_reset_returns_nil
     assert_nil p.author.reset
   end
 
-  def test_reset_loads_association_next_time
-    welcome = posts(:welcome)
-    david = authors(:david)
-    author_assoc = welcome.author
-
-    assert_equal david, welcome.author # So we can be sure the test works correctly
-    author_assoc.reset
-    assert !author_assoc.loaded?
-    assert_nil author_assoc.target
-    assert_equal david, welcome.author
-  end
-
-  def test_assigning_association_id_after_reload
-    welcome = posts(:welcome)
-    welcome.reload
-    assert_nothing_raised do
-      welcome.author_id = authors(:david).id
-    end
-  end
-
   def test_reload_returns_assocition
     david = developers(:david)
     assert_nothing_raised do