deal with removing connections associated with the current thread

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

@@ -222,6 +222,13 @@ module ActiveRecord
       def remove(conn)
         synchronize do
           @connections.delete conn
+
+          # FIXME: we might want to store the key on the connection so that removing
+          # from the reserved hash will be a little easier.
+          thread_id = @reserved_connections.keys.find { |k|
+            @reserved_connections[k] == conn
+          }
+          @reserved_connections.delete thread_id if thread_id
         end
       end
 

activerecord/test/cases/connection_pool_test.rb

@@ -37,6 +37,14 @@ module ActiveRecord
         conn.close
       end
 
+      def test_remove_connection_for_thread
+        conn = @pool.connection
+        @pool.remove conn
+        assert_not_equal(conn, @pool.connection)
+      ensure
+        conn.close
+      end
+
       def test_active_connection?
         assert !@pool.active_connection?
         assert @pool.connection