The bug

The list of blocks that appear under "can place on" when a block is placeable in adventure mode gets shuffled into a random order after relogging.

How to reproduce

/give @p stone 1 0 {"can_place_on":{"blocks":["stone","dirt","planks","log","leaves"]}}

Look at the item tooltip, then relog and look again

Expected behavior
Items appear consistently in the order specified: Stone, Dirt, Planks, Log, Leaves

Actual behavior
Items are in a random order both times