LinBus fails to deserialize BaseItem using BaseItemAdapter

Server Implementation

Paper

Server Version

1.21.3

Describe the bug

Most likely since the LinBus introduction?

To Reproduce

session data (in sessions folder):

{"selector":"CUBOID","useServerCUI":false,"wandItem":{"itemType":{"id":"minecraft:wooden_axe"},"nbt":"{}"},"navWandItem":{"itemType":{"id":"minecraft:compass"}}}

Expected behaviour

Screenshots / Videos

No response

Error log (if applicable)

No response

Fawe Debugpaste

Fawe Version

Checklist

• I have included a Fawe debugpaste.
• I am using the newest build from https://ci.athion.net/job/FastAsyncWorldEdit/ and the issue still persists.

Anything else?

Caused by: org.enginehub.linbus.stream.exception.NbtParseException: At character index 1: Unexpected token: '}', expected Text
        at FastAsyncWorldEdit-Bukkit-2.12.1-SNAPSHOT-965.jar/org.enginehub.linbus.format.snbt.impl.reader.LinSnbtReader.unexpectedTokenSpecificError(LinSnbtReader.java:165) ~[FastAsyncWorldEdit-Bukkit-2.12.1-SNAPSHOT-965.jar:?]
        at FastAsyncWorldEdit-Bukkit-2.12.1-SNAPSHOT-965.jar/org.enginehub.linbus.format.snbt.impl.reader.LinSnbtReader.readName(LinSnbtReader.java:256) ~[FastAsyncWorldEdit-Bukkit-2.12.1-SNAPSHOT-965.jar:?]
        at FastAsyncWorldEdit-Bukkit-2.12.1-SNAPSHOT-965.jar/org.enginehub.linbus.format.snbt.impl.reader.LinSnbtReader.fillTokenStack(LinSnbtReader.java:187) ~[FastAsyncWorldEdit-Bukkit-2.12.1-SNAPSHOT-965.jar:?]
        at FastAsyncWorldEdit-Bukkit-2.12.1-SNAPSHOT-965.jar/org.enginehub.linbus.format.snbt.impl.reader.LinSnbtReader.nextOrNull(LinSnbtReader.java:176) ~[FastAsyncWorldEdit-Bukkit-2.12.1-SNAPSHOT-965.jar:?]
        at FastAsyncWorldEdit-Bukkit-2.12.1-SNAPSHOT-965.jar/org.enginehub.linbus.stream.impl.OptionalInfoCalculator.nextOrNull(OptionalInfoCalculator.java:68) ~[FastAsyncWorldEdit-Bukkit-2.12.1-SNAPSHOT-965.jar:?]
        at FastAsyncWorldEdit-Bukkit-2.12.1-SNAPSHOT-965.jar/org.enginehub.linbus.tree.impl.LinTagReader.readCompound(LinTagReader.java:93) ~[FastAsyncWorldEdit-Bukkit-2.12.1-SNAPSHOT-965.jar:?]
        at FastAsyncWorldEdit-Bukkit-2.12.1-SNAPSHOT-965.jar/org.enginehub.linbus.tree.LinCompoundTag.readFrom(LinCompoundTag.java:257) ~[FastAsyncWorldEdit-Bukkit-2.12.1-SNAPSHOT-965.jar:?]
        at FastAsyncWorldEdit-Bukkit-2.12.1-SNAPSHOT-965.jar/com.fastasyncworldedit.core.util.gson.BaseItemAdapter.deserialize(BaseItemAdapter.java:42) ~[FastAsyncWorldEdit-Bukkit-2.12.1-SNAPSHOT-965.jar:?]
        at FastAsyncWorldEdit-Bukkit-2.12.1-SNAPSHOT-965.jar/com.fastasyncworldedit.core.util.gson.BaseItemAdapter.deserialize(BaseItemAdapter.java:21) ~[FastAsyncWorldEdit-Bukkit-2.12.1-SNAPSHOT-965.jar:?]
        at com.google.gson.internal.bind.TreeTypeAdapter.read(TreeTypeAdapter.java:76) ~[gson-2.10.1.jar:?]
        at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.readIntoField(ReflectiveTypeAdapterFactory.java:212) ~[gson-2.10.1.jar:?]
        at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$FieldReflectionAdapter.readField(ReflectiveTypeAdapterFactory.java:433) ~[gson-2.10.1.jar:?]
        at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:393) ~[gson-2.10.1.jar:?]
        at com.google.gson.Gson.fromJson(Gson.java:1227) ~[gson-2.10.1.jar:?]
        at com.google.gson.Gson.fromJson(Gson.java:1137) ~[gson-2.10.1.jar:?]
        at com.google.gson.Gson.fromJson(Gson.java:1075) ~[gson-2.10.1.jar:?]
        at FastAsyncWorldEdit-Bukkit-2.12.1-SNAPSHOT-965.jar/com.sk89q.worldedit.session.storage.JsonFileSessionStore.load(JsonFileSessionStore.java:104) ~[FastAsyncWorldEdit-Bukkit-2.12.1-SNAPSHOT-965.jar:?]
        at FastAsyncWorldEdit-Bukkit-2.12.1-SNAPSHOT-965.jar/com.sk89q.worldedit.session.SessionManager.get(SessionManager.java:160) ~[FastAsyncWorldEdit-Bukkit-2.12.1-SNAPSHOT-965.jar:?]
        at FastAsyncWorldEdit-Bukkit-2.12.1-SNAPSHOT-965.jar/com.sk89q.worldedit.extension.platform.PlatformManager.handleBlockInteract(PlatformManager.java:393) ~[FastAsyncWorldEdit-Bukkit-2.12.1-SNAPSHOT-965.jar:?]
        at FastAsyncWorldEdit-Bukkit-2.12.1-SNAPSHOT-965.jar/com.sk89q.worldedit.util.eventbus.MethodHandleEventHandler.dispatch(MethodHandleEventHandler.java:51) ~[FastAsyncWorldEdit-Bukkit-2.12.1-SNAPSHOT-965.jar:?]
        at FastAsyncWorldEdit-Bukkit-2.12.1-SNAPSHOT-965.jar/com.sk89q.worldedit.util.eventbus.EventHandler.handleEvent(EventHandler.java:73) ~[FastAsyncWorldEdit-Bukkit-2.12.1-SNAPSHOT-965.jar:?]```

Start with com.fastasyncworldedit.core.util.gson.BaseItemAdapter.deserialize and the failing path through LinCompoundTag.readFrom and LinSnbtReader.readName. Reproduce loading the session JSON containing an empty "nbt":"{}" value, then inspect the relevant LinBus parsing behavior. Done means the BaseItem data deserializes without the reported NbtParseException and the regression is covered by an appropriate test.