Linux and Windows
2.76.2
Broken: 95164a0
In the texture paint mode, into Slots, choose "Image" from "Painting Mode", and the viewport doesn't change.
I solve the problem using the material slots, but "Image" is a good option for work!
Create a uvs in the default cube.
Create a new image.
Go to Texture Paint. Slots > Painting Mode Image, and select the image. Viewport don't show it. But if you paint over the cube the image change!
Thanks!