Restore query cache on rollback

activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb

@@ -258,7 +258,18 @@ def commit_db_transaction()   end
 
       # Rolls back the transaction (and turns on auto-committing). Must be
       # done if the transaction block raises an exception or returns false.
-      def rollback_db_transaction() end
+      def rollback_db_transaction
+        exec_rollback_db_transaction
+      end
+
+      def exec_rollback_db_transaction() end #:nodoc:
+
+      def rollback_to_savepoint(name = nil)
+        exec_rollback_to_savepoint(name)
+      end
+
+      def exec_rollback_to_savepoint(name = nil) #:nodoc:
+      end
 
       def default_sequence_name(table, column)
         nil

activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb

@@ -3,7 +3,7 @@ module ConnectionAdapters # :nodoc:
     module QueryCache
       class << self
         def included(base) #:nodoc:
-          dirties_query_cache base, :insert, :update, :delete
+          dirties_query_cache base, :insert, :update, :delete, :rollback_to_savepoint, :rollback_db_transaction
         end
 
         def dirties_query_cache(base, *method_names)

activerecord/lib/active_record/connection_adapters/abstract/savepoints.rb

@@ -9,7 +9,7 @@ def create_savepoint(name = current_savepoint_name)
         execute("SAVEPOINT #{name}")
       end
 
-      def rollback_to_savepoint(name = current_savepoint_name)
+      def exec_rollback_to_savepoint(name = current_savepoint_name)
         execute("ROLLBACK TO SAVEPOINT #{name}")
       end
 

activerecord/lib/active_record/connection_adapters/abstract_adapter.rb

@@ -341,9 +341,6 @@ def raw_connection
       def create_savepoint(name = nil)
       end
 
-      def rollback_to_savepoint(name = nil)
-      end
-
       def release_savepoint(name = nil)
       end
 

activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb

@@ -324,7 +324,7 @@ def commit_db_transaction #:nodoc:
         execute "COMMIT"
       end
 
-      def rollback_db_transaction #:nodoc:
+      def exec_rollback_db_transaction #:nodoc:
         execute "ROLLBACK"
       end
 

activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb

@@ -223,7 +223,7 @@ def commit_db_transaction
         end
 
         # Aborts a transaction.
-        def rollback_db_transaction
+        def exec_rollback_db_transaction
           execute "ROLLBACK"
         end
       end

activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb

@@ -361,7 +361,7 @@ def commit_db_transaction #:nodoc:
         log('commit transaction',nil) { @connection.commit }
       end
 
-      def rollback_db_transaction #:nodoc:
+      def exec_rollback_db_transaction #:nodoc:
         log('rollback transaction',nil) { @connection.rollback }
       end
 

activerecord/test/cases/query_cache_test.rb

@@ -212,6 +212,38 @@ def test_cache_is_available_when_connection_is_connected
   ensure
     ActiveRecord::Base.configurations = conf
   end
+
+  def test_query_cache_doesnt_leak_cached_results_of_rolled_back_queries
+    ActiveRecord::Base.connection.enable_query_cache!
+    post = Post.first
+
+    Post.transaction do
+      post.update_attributes(title: 'rollback')
+      assert_equal 1, Post.where(title: 'rollback').to_a.count
+      raise ActiveRecord::Rollback
+    end
+
+    assert_equal 0, Post.where(title: 'rollback').to_a.count
+
+    ActiveRecord::Base.connection.uncached do
+      assert_equal 0, Post.where(title: 'rollback').to_a.count
+    end
+
+    begin
+      Post.transaction do
+        post.update_attributes(title: 'rollback')
+        assert_equal 1, Post.where(title: 'rollback').to_a.count
+        raise 'broken'
+      end
+    rescue Exception
+    end
+
+    assert_equal 0, Post.where(title: 'rollback').to_a.count
+
+    ActiveRecord::Base.connection.uncached do
+      assert_equal 0, Post.where(title: 'rollback').to_a.count
+    end
+  end
 end
 
 class QueryCacheExpiryTest < ActiveRecord::TestCase