NPE console spam with OMT trying to write a null player?

[LemADEC]

As of omlib-1.12.2-3.2.0-256 + openmodularturrets-1.12.2-3.2.0-379, a console spam was observed which leads to a GC overload which caused a server crash. According to the player in the area, that turret got corrupted/missing at some point then reappeared randomly.
Notable call stack in the spam:

[15:44:19] [Server thread/ERROR] [FML]: SimpleChannelHandlerWrapper exception
io.netty.handler.codec.EncoderException: java.lang.NullPointerException
	at io.netty.handler.codec.MessageToMessageEncoder.write(MessageToMessageEncoder.java:106) ~[minecraft_server.1.12.2.jar:?]
	at io.netty.handler.codec.MessageToMessageCodec.write(MessageToMessageCodec.java:116) ~[minecraft_server.1.12.2.jar:?]
	at io.netty.channel.AbstractChannelHandlerContext.invokeWrite0(AbstractChannelHandlerContext.java:738) ~[minecraft_server.1.12.2.jar:?]
	at io.netty.channel.AbstractChannelHandlerContext.invokeWriteAndFlush(AbstractChannelHandlerContext.java:801) ~[minecraft_server.1.12.2.jar:?]
	at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:814) ~[minecraft_server.1.12.2.jar:?]
	at io.netty.channel.AbstractChannelHandlerContext.writeAndFlush(AbstractChannelHandlerContext.java:794) ~[minecraft_server.1.12.2.jar:?]
	at io.netty.channel.AbstractChannelHandlerContext.writeAndFlush(AbstractChannelHandlerContext.java:831) ~[minecraft_server.1.12.2.jar:?]
	at io.netty.channel.DefaultChannelPipeline.writeAndFlush(DefaultChannelPipeline.java:1032) ~[minecraft_server.1.12.2.jar:?]
	at io.netty.channel.AbstractChannel.writeAndFlush(AbstractChannel.java:296) ~[minecraft_server.1.12.2.jar:?]
	at net.minecraftforge.fml.common.network.simpleimpl.SimpleNetworkWrapper.sendToAllTracking(SimpleNetworkWrapper.java:279) [SimpleNetworkWrapper.class:?]
	at omtteam.openmodularturrets.tileentity.TurretBase.informUpdate(TurretBase.java:352) [TurretBase.class:?]
	at omtteam.openmodularturrets.tileentity.TurretBase.TickCentral_TrueITickableUpdate(TurretBase.java:390) [TurretBase.class:?]
	at com.github.terminatornl.tickcentral.api.TickHub.trueUpdate(TickHub.java:48) [TickHub.class:3.2]
	at com.github.terminatornl.tickcentral.api.TickInterceptor.redirectUpdate(TickInterceptor.java:24) [TickInterceptor.class:3.2]
	at omtteam.openmodularturrets.tileentity.TurretBase.func_73660_a(TurretBase.java) [TurretBase.class:?]
	at org.spongepowered.common.event.tracking.TrackingUtil.tickTileEntity(TrackingUtil.java:237) [spongeforge-1.12.2-2838-7.3.0.jar:1.12.2-2838-7.3.0]
	at net.minecraft.world.WorldServer.updateTileEntity(WorldServer.java:4749) [oo.class:?]
	at net.minecraft.world.WorldServer.redirect$zlo000$onUpdateTileEntities(WorldServer.java:4733) [oo.class:?]
	at net.minecraft.world.World.func_72939_s(World.java:1838) [amu.class:?]
	at net.minecraft.world.WorldServer.func_72939_s(WorldServer.java:3931) [oo.class:?]
	at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:767) [MinecraftServer.class:?]
	at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:397) [nz.class:?]
	at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:668) [MinecraftServer.class:?]
	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:526) [MinecraftServer.class:?]
	at java.lang.Thread.run(Thread.java:748) [?:1.8.0_262]
Caused by: java.lang.NullPointerException
	at omtteam.omlib.util.player.Player.writeToByteBuf(Player.java:45) ~[Player.class:?]
	at omtteam.openmodularturrets.network.messages.MessageTurretBase.toBytes(MessageTurretBase.java:118) ~[MessageTurretBase.class:?]
	at net.minecraftforge.fml.common.network.simpleimpl.SimpleIndexedCodec.encodeInto(SimpleIndexedCodec.java:30) ~[SimpleIndexedCodec.class:?]
	at net.minecraftforge.fml.common.network.simpleimpl.SimpleIndexedCodec.encodeInto(SimpleIndexedCodec.java:26) ~[SimpleIndexedCodec.class:?]
	at net.minecraftforge.fml.common.network.FMLIndexedMessageToMessageCodec.encode(FMLIndexedMessageToMessageCodec.java:81) ~[FMLIndexedMessageToMessageCodec.class:?]
	at io.netty.handler.codec.MessageToMessageCodec$1.encode(MessageToMessageCodec.java:67) ~[minecraft_server.1.12.2.jar:?]
	at io.netty.handler.codec.MessageToMessageEncoder.write(MessageToMessageEncoder.java:88) ~[minecraft_server.1.12.2.jar:?]
	... 24 more

From a quick look at the callstack, it seems caused by a null player.
We've no clue at this point how the turret got corrupted, but sanitizing inputs from that Player.writeToByteBuf() function would save from crashing the server next time it happens.

[Keridos]

Interesting, I will check that out. Currently I am in the middle of rewriting the Turrets rendering stuff, so I do not exactly know when this will be fixed.