the blocks in question are all the saplings, flower pot, any block that can be placed on another block, heads,and all rails,
Comments 4
Not tile entities, but blocks with materials marked as not solid (which, in MCP, are Material.plants and Material.circuits). Those seem to be explicitly allowed for in the code.
I don't think this is a bug. Do you know if cactus is not supposed to be able to be placed next to anything at all? I thought it was just other cactus blocks.