Normally jumping onto powder snow without leather boots, including jumping to the edge, causes player to fall through it. This works for both creative and survival modes. In survival, this does not cause fall damage.

Observed
However, if you jump from a high place (e.g. 8blocks high) to the powder snow and fall exactly onto the edge, you can then jump up even if you don't wear leather boots.

Expected
You wouldn't be able to jump on the edge of powdered snow

How to reproduce this bug:

1. Create a new world. Cheating should be allowed.
2. /fill 0 256 0 5 256 5 powder_snow 
3. /tp @s 0.0 320.0 -0.15
4. Press SPACE while falling.