Block 36 (piston_extension) can be destroyed in adventure mode

This is a useful feature. I don't know why anyone would want this removed.

why is this useful?

Invisible block interaction using testforblck ~~ ~ air

oh, you can use it as a fancy button/lever, why do I never come up with good ideas D:

Well, I personally think it's more useful to have a block that mobs can't go (pathfind) through and players can. But thats my opinion.

Then spam create it where you want these "barriers".

Cannot reproduce.

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.

Ticket resolved as incomplete, because no answer in a reasonable amount of time (1+ year), if it still happens, please update the ticket.