[MC-87223] Changing command block type crashes game (impulse, chain, or repeat)

What I expected to happen was...:
Pressing the button would change the command block type

What actually happened was...:
game crashed

Steps to Reproduce:
1. Place any command block down
2. Right click on it
3. Click on the button that now always says chain

java.lang.NullPointerException: Updating screen events
	at bcu.h(SourceFile:228)
	at bcu.a(SourceFile:134)
	at bbx.a(SourceFile:341)
	at bcu.a(SourceFile:167)
	at bbx.k(SourceFile:404)
	at bbx.p(SourceFile:381)
	at azh.s(SourceFile:1532)
	at azh.av(SourceFile:926)
	at azh.a(SourceFile:375)
	at net.minecraft.client.main.Main.main(SourceFile:125)