Ensure ActiveRecord::ConnectionPool.connected? handles undefined connections. [#936 state:resolved]

Signed-off-by: Pratik Naik <pratiknaik@gmail.com>

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

@@ -324,7 +324,7 @@ module ActiveRecord
       # Returns true if a connection that's accessible to this class has
       # already been opened.
       def connected?(klass)
-        retrieve_connection_pool(klass).connected?
+        conn = retrieve_connection_pool(klass) ? conn.connected? : false
       end
 
       # Remove the connection for this class. This will close the active

activerecord/test/cases/pooled_connections_test.rb

@@ -73,6 +73,14 @@ class PooledConnectionsTest < ActiveRecord::TestCase
     assert ActiveRecord::ConnectionAdapters::AbstractAdapter === conn
     conn_pool.checkin(conn)
   end
+
+  def test_undefined_connection_returns_false
+    old_handler = ActiveRecord::Base.connection_handler
+    ActiveRecord::Base.connection_handler = ActiveRecord::ConnectionAdapters::ConnectionHandler.new
+    assert_equal false, ActiveRecord::Base.connected?
+  ensure
+    ActiveRecord::Base.connection_handler = old_handler
+  end
 end unless %w(FrontBase).include? ActiveRecord::Base.connection.adapter_name
 
 class AllowConcurrencyDeprecatedTest < ActiveRecord::TestCase