Whenever I try to use the /spawnpoint command through command blocks, and command blocks only, nothing happens, even when arguments are added. No matter what I try, levers, buttons, everything, nothing works. To reproduce, simple use the /spawnpoint [@a, @p, @r] [x] [y] [z] command in a command block and use a lever or button or whatever to create a redstone signal.The command works fine when applied manually through chat. Also, it has the same result no matter what game mode I am currently in. I first noticed this in 1.5.2, but it could have been present at 1.5.1.

Summary

What I expected to happen for the /spawnpoint command to set my spawnpoint to 1.5 237 7.5

what actually happened Nothing. The command simply didn't work.

steps to reproduce Remember to create a new world, so your spawnpoint has not been set manually already.
1. Place a command block.
2. input the command /spawnpoint [@a, @p, @r] 0 4 0 (example, use any coordinates)
3. kill yourself.
4. notice that nothing happened. How am I supposed to set spawnpoints in my adventure map?