I spawned a regular piston (ID 33) with the orientation data 6 (which is not a normal placeable direction) per /setblock command and then just wondered what happens if you power it. Well, the game crashed, that is kinda what I expected :/(Sorry if this is a duplicate, but I did not find any by using the search) +The marked duplicate is closed as "invalid" as it was created using external tools. This is not (Note the last line of the crash report:
Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.
+
Also I could not test if this happens in previous versions, but I believe so as you can place such a block with external tools (such as WorldEdit).
//EDIT: Yes, this happens.
If you don't believe me, reproduce:
Type "/setblock ~ ~ ~ 33 6 replace"
Provide redstone power to the spawned block.
Crash log and screenshot of the piston attached.
Please reopen, MC-13252 is closed as "invalid" because the block was spawned with external tools. This is spawned using the new /setblock command (and therefore using only methods Minecraft provides)