I have a 1280x800 monitor, so that size or bigger could be needed to reproduce. I think.
What I expected to happen was...:
When I clicked Maximize, Minecraft would maximize; you know, like it should.

What actually happened was...:
Minecraft crashed back to launcher.

Steps to Reproduce:
1. Set up a profile using 13w48b
2. Start game
3. Click Maximize
4. Game crashes

note: fatal error by Java Runtime Environment "EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x000000004eee55ec, pid=7864, tid=2796
"