When placing certain heads or putting them in entities' head slot the game stutters

Give yourself a head with SkullOwner being the f word (Or any invalid name it seems) then place it on the ground this will make the game stutter this also will happen when putting this head and others on entities.
This may relate to MC-159202

Error executing task on Server

java.util.ConcurrentModificationException
	at java.util.LinkedList$ListItr.checkForComodification(LinkedList.java:966)
	at java.util.LinkedList$ListItr.next(LinkedList.java:888)
	at com.google.common.collect.Iterators$8.next(Iterators.java:896)
	at com.google.common.collect.Iterators.addAll(Iterators.java:367)
	at com.google.common.collect.Lists.newArrayList(Lists.java:165)
	at abl.a(SourceFile:214)
	at abl.c(SourceFile:198)
	at abl.a(SourceFile:146)
	at cei.b(SourceFile:130)
	at cei.f(SourceFile:113)
	at cei.a(SourceFile:109)
	at bzw.a(SourceFile:43)
	at bim.a(SourceFile:81)
	at bim.a(SourceFile:41)
	at bki.a(SourceFile:213)
	at zf.a(SourceFile:345)
	at zv.a(SourceFile:976)
	at sq.a(SourceFile:36)
	at sq.a(SourceFile:10)
	at nk.a(SourceFile:21)
	at uy.run(SourceFile:18)
	at amn.c(SourceFile:144)
	at amr.c(SourceFile:23)
	at net.minecraft.server.MinecraftServer.b(SourceFile:763)
	at net.minecraft.server.MinecraftServer.c(SourceFile:154)
	at amn.x(SourceFile:118)
	at net.minecraft.server.MinecraftServer.aZ(SourceFile:745)
	at net.minecraft.server.MinecraftServer.x(SourceFile:739)
	at amn.c(SourceFile:127)
	at net.minecraft.server.MinecraftServer.w(SourceFile:724)
	at net.minecraft.server.MinecraftServer.v(SourceFile:676)
	at net.minecraft.server.MinecraftServer.a(SourceFile:256)
	at java.lang.Thread.run(Thread.java:745)

Error executing task on Client

java.lang.NullPointerException
	at java.util.LinkedList$ListItr.next(LinkedList.java:893)
	at com.google.common.collect.Iterators$8.next(Iterators.java:896)
	at com.google.common.collect.Iterators.addAll(Iterators.java:367)
	at com.google.common.collect.Lists.newArrayList(Lists.java:165)
	at abl.a(SourceFile:214)
	at abl.c(SourceFile:198)
	at abl.a(SourceFile:146)
	at cei.b(SourceFile:130)
	at cei.f(SourceFile:113)
	at cei.a(SourceFile:109)
	at cei.a(SourceFile:62)
	at dyn.a(SourceFile:1248)
	at nv.a(SourceFile:55)
	at nv.a(SourceFile:11)
	at nk.a(SourceFile:21)
	at amn.c(SourceFile:144)
	at amr.c(SourceFile:23)
	at amn.x(SourceFile:118)
	at amn.bj(SourceFile:103)
	at dlx.e(SourceFile:988)
	at dlx.e(SourceFile:654)
	at net.minecraft.client.main.Main.main(SourceFile:215)