What should have happened was that when I stand on a slab which is on the lower side of a block i could place a slab on the FULL block two blocks above so there is 2 blocks space in-between.
When i stand on a bottom slab i can not place a upperslab above my head onto a FULL block (so there is two meters distance in-between). I can although place a slab there if i place it onto a upper slab.
Stand on a lower half slab and try to place a upper slab on the full block on top of you, e.g. a upper slab onto a stone block. If you actually place the slab ontop of you onto an other slab it will work.
Is this still a concern in the current Minecraft version? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases. If this has been done, we can reopen the issue.
Keep in mind that the "Resolved"-Status on this ticket just means "Answered", and that we are waiting for further information on whether this issue still exists or not. We will reopen it as soon as the requested information has been delivered.