[SPIGOT-5943] Calling get BlockStateMeta#getBlockState causes NPE with shield with banner Created: 05/Jul/20  Updated: 05/Jul/20  Resolved: 05/Jul/20

Status: Resolved
Project: Spigot
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Bug Priority: Minor
Reporter: Phoenix616 Assignee: Unassigned
Resolution: Fixed Votes: 0
Labels: api, bug
Environment:

openjdk 14 2020-03-17
OpenJDK Runtime Environment AdoptOpenJDK (build 14+36)
OpenJDK 64-Bit Server VM AdoptOpenJDK (build 14+36, mixed mode, sharing)

Version: git-Spigot-ccb012a-e58a088
Guidelines Read: Yes

 Description   

When calling BlockStateMeta#getBlockState on a shield that has a banner pattern applied to it it causes a NullPointerException. E.g. this stacktrace 1.5.7 of my ShowItem plugin, with enabled ShowCodeDetailsInExceptionMessages of Java 14:

[01:33:10] [Server thread/INFO]: Phoenix616 issued server command: /show
[01:33:10] [Server thread/ERROR]: null
org.bukkit.command.CommandException: Unhandled exception executing command 'show' in plugin ShowItem v1.5.7 (compiled at 2020-07-05T00:19:32Z)
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:47) ~[spigot.jar:git-Spigot-ccb012a-e58a088]
	at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:149) ~[spigot.jar:git-Spigot-ccb012a-e58a088]
	at org.bukkit.craftbukkit.v1_16_R1.CraftServer.dispatchCommand(CraftServer.java:757) ~[spigot.jar:git-Spigot-ccb012a-e58a088]
	at net.minecraft.server.v1_16_R1.PlayerConnection.handleCommand(PlayerConnection.java:1703) ~[spigot.jar:git-Spigot-ccb012a-e58a088]
	at net.minecraft.server.v1_16_R1.PlayerConnection.a(PlayerConnection.java:1546) ~[spigot.jar:git-Spigot-ccb012a-e58a088]
	at net.minecraft.server.v1_16_R1.PacketPlayInChat.a(PacketPlayInChat.java:47) ~[spigot.jar:git-Spigot-ccb012a-e58a088]
	at net.minecraft.server.v1_16_R1.PacketPlayInChat.a(PacketPlayInChat.java:1) ~[spigot.jar:git-Spigot-ccb012a-e58a088]
	at net.minecraft.server.v1_16_R1.PlayerConnectionUtils.lambda$0(PlayerConnectionUtils.java:19) ~[spigot.jar:git-Spigot-ccb012a-e58a088]
	at net.minecraft.server.v1_16_R1.TickTask.run(SourceFile:18) ~[spigot.jar:git-Spigot-ccb012a-e58a088]
	at net.minecraft.server.v1_16_R1.IAsyncTaskHandler.executeTask(SourceFile:144) ~[spigot.jar:git-Spigot-ccb012a-e58a088]
	at net.minecraft.server.v1_16_R1.IAsyncTaskHandlerReentrant.executeTask(SourceFile:23) ~[spigot.jar:git-Spigot-ccb012a-e58a088]
	at net.minecraft.server.v1_16_R1.IAsyncTaskHandler.executeNext(SourceFile:118) ~[spigot.jar:git-Spigot-ccb012a-e58a088]
	at net.minecraft.server.v1_16_R1.MinecraftServer.aZ(MinecraftServer.java:943) ~[spigot.jar:git-Spigot-ccb012a-e58a088]
	at net.minecraft.server.v1_16_R1.MinecraftServer.executeNext(MinecraftServer.java:936) ~[spigot.jar:git-Spigot-ccb012a-e58a088]
	at net.minecraft.server.v1_16_R1.IAsyncTaskHandler.awaitTasks(SourceFile:127) ~[spigot.jar:git-Spigot-ccb012a-e58a088]
	at net.minecraft.server.v1_16_R1.MinecraftServer.sleepForTick(MinecraftServer.java:920) ~[spigot.jar:git-Spigot-ccb012a-e58a088]
	at net.minecraft.server.v1_16_R1.MinecraftServer.v(MinecraftServer.java:852) ~[spigot.jar:git-Spigot-ccb012a-e58a088]
	at net.minecraft.server.v1_16_R1.MinecraftServer.lambda$0(MinecraftServer.java:164) ~[spigot.jar:git-Spigot-ccb012a-e58a088]
	at java.lang.Thread.run(Thread.java:832) [?:?]
Caused by: java.lang.NullPointerException: Cannot invoke "net.minecraft.server.v1_16_R1.Block.getBlockData()" because the return value of "org.bukkit.craftbukkit.v1_16_R1.util.CraftMagicNumbers.getBlock(org.bukkit.Material)" is null
	at org.bukkit.craftbukkit.v1_16_R1.inventory.CraftMetaBlockState.getBlockState(CraftMetaBlockState.java:301) ~[spigot.jar:git-Spigot-ccb012a-e58a088]
	at de.themoep.utils.ItemMatcher$MatchDefinition.matches(ItemMatcher.java:188) ~[?:?]
	at de.themoep.utils.ItemMatcher.getMatching(ItemMatcher.java:63) ~[?:?]
	at de.themoep.ShowItem.ShowItemCommand.onCommand(ShowItemCommand.java:169) ~[?:?]
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:45) ~[spigot.jar:git-Spigot-ccb012a-e58a088]
	... 18 more

This happens no matter if hasBlockState was checked before or not. (But that shouldn't matter anyways, getBlockState should return a fresh one if the meta doesn't have a state.

As far as I can tell this happens because CraftMagicNumbers#getBlock tries to use the material of the item to get a block which a shield obviously isn't. It seem like there is more special-casing necessary for shields than what is already in place.

 Comments   
Comment by md_5 [ 05/Jul/20 ]

is this new in 1.16?

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