[MC-122351] Crash when exiting a world: java.lang.ArrayIndexOutOfBoundsException: -1

The bug

When clicking 'Save and quit to title', the client crashes instantly.

Crash reports

1. In 17w47a

17w47a: crash-2017-11-22_18.35.11-client.txt

Description: Unexpected error

java.lang.ArrayIndexOutOfBoundsException: -1
	at java.util.ArrayList.elementData(ArrayList.java:418)
	at java.util.ArrayList.remove(ArrayList.java:495)
	at uf.e(SourceFile:103)
	at bmg.b(SourceFile:877)
	at bmg.a(SourceFile:369)
	at net.minecraft.client.main.Main.main(SourceFile:134)

2. In 18w14b
crash-2018-04-11_00.17.13-client.txt