David A. Brown
Assigned
Reported
Comments
1.5pre, SMP : Placing a map into an item frame adds a green arrow to the map, at the player's location, pointing in the opposite direction of the player. Doing this again adds another similar arrow to the map, up to a maximum of four. These arrows persist until the server is stopped and restarted: this removes all green markers from all maps, except those are in item frames, which retain one marker at their current location.
They can only escape through transparent blocks: steps, fences, "walls", glass. They will not escape through solid blocks. Animals which are standing very close to / inside these types of blocks may suffocate en masse when the world/chunk is loaded. (MC 1.5)
(Even with an enclosure of all solid blocks, and plenty of room to move, they will sometimes push each other into the wall and suffocate. Also, network latency can cause them to appear to "slide" out of their enclosure, then pop back in when the connection catches up. These are probably separate issues.)
Still a problem in 13w10a.
Nathan Gorzelanczyk: My testing was done in SMP with a reasonable number of mobs in the enclosure (the average use case). I re-tested in Creative mode, and you are correct: if enough animals are in the enclosure that they are intersecting the walls (as in screenshot-2.jpg), reloading a chunk will indeed cause some of them to appear on the other side – regardless of the enclosure material. Also, packing in a ridiculous amount of mobs will also cause the visual "sliding" (MC-11086), even in single-player where lag can't be the cause.