Trapped in "Future Starter" - A Challenge for Portal Masters

I've started recording all of the Portal 2 maps where the player is able to trap themselves. Normally, the game knows it is possible to get trapped in a certain map, and it then gives you a way out, including "Smooth Jazz," Turret Blocker," and "Ricochet" - My videos will be showing traps that game developers did not forsee. This video shows me getting trapped in "Future Starter" after clipping the cube through the door. No other cubes are dropped, so the only possible way to continue is to activate the "button save glitch" - If you can successfully perform the glitch, or find another solution, post a video of your solution. Upcoming challenges are going to be much harder, if not impossible, to solve!