You can reverse that situation by turning the glass upside-down.
If a half full glass falls over in the woods and no one is there to see it - does it still spill?
My glass is plastic.
The glass complement has been rationalized.
Would you like fries with that?
If my glass is half full when it is spilled, then it becomes empty and needs a refill.
If my glass is half empty when it is spilled, then it half doesn’t spill.
Schrödinger’s glass is simultaneously full and empty.
You can’t simultaneously know how full Heisenbergs’s glass is and what he’s drinking.
My cup runneth over.
Your cup runneth over my dog 
I’ve got two glasses; one for each of ya.
Make my double a triple.
Glass? I don’t need no steenkin’ glass!
Is it really glass? Or just a matrix of energy that, until rotated, prevents another matrix of energy from following curved space-time?
Your ass is glass.
I keep half my water in a redundant glass.
If it’s one of my glasses, my klepto friend Maria probably stole it on the way out from one of my parties!
I miss more glasses that way.
Chuck Norris doesn’t need a glass.
ETA: I hate myself.
In soviet Russia, glass philosophises you.
All your glass are belong to… Ow! Hey! Quiddit!! OW!!! GERROFF!!!
There is no glass.
- The Matrix