Make SQLite3 pass the unit tests for savepoints.

activerecord/lib/active_record/connection_adapters/abstract_adapter.rb

@@ -65,6 +65,12 @@ def supports_count_distinct?
       def supports_ddl_transactions?
         false
       end
+
+      # Does this adapter support savepoints? PostgreSQL and MySQL do, SQLite
+      # does not.
+      def supports_savepoints?
+        false
+      end
 
       # Should primary key values be selected from their corresponding
       # sequence before the insert statement?  If true, next_sequence_value

activerecord/lib/active_record/connection_adapters/mysql_adapter.rb

@@ -205,6 +205,10 @@ def adapter_name #:nodoc:
       def supports_migrations? #:nodoc:
         true
       end
+
+      def supports_savepoints? #:nodoc:
+        true
+      end
 
       def native_database_types #:nodoc:
         NATIVE_DATABASE_TYPES

activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb

@@ -272,6 +272,10 @@ def supports_insert_with_returning?
       def supports_ddl_transactions?
         true
       end
+
+      def supports_savepoints?
+        true
+      end
 
       # Returns the configured supported identifier length supported by PostgreSQL,
       # or report the default of 63 on PostgreSQL 7.x.

activerecord/test/cases/transactions_test.rb

@@ -239,7 +239,7 @@ def test_force_savepoint_in_nested_transaction
 
     assert @first.reload.approved?
     assert !@second.reload.approved?
-  end
+  end if Topic.connection.supports_savepoints?
 
   def test_no_savepoint_in_nested_transaction_without_force
     Topic.transaction do
@@ -260,7 +260,7 @@ def test_no_savepoint_in_nested_transaction_without_force
 
     assert !@first.reload.approved?
     assert !@second.reload.approved?
-  end
+  end if Topic.connection.supports_savepoints?
 
   def test_many_savepoints
     Topic.transaction do
@@ -304,7 +304,7 @@ def test_many_savepoints
     assert_equal "One", @one
     assert_equal "Two", @two
     assert_equal "Three", @three
-  end
+  end if Topic.connection.supports_savepoints?
 
   uses_mocha 'mocking connection.commit_db_transaction' do
     def test_rollback_when_commit_raises
@@ -411,7 +411,7 @@ def test_no_automatic_savepoint_for_inner_transaction
 
     assert !@first.reload.approved?
   end
-end
+end if Topic.connection.supports_savepoints?
 
 if current_adapter?(:PostgreSQLAdapter)
   class ConcurrentTransactionTest < TransactionTest