[MC-124112] Renamed placed droppers lose their custom name when upgrading from 1.12.2

To reproduce, rename and place a dropper in 1.12.2 and open the world in 18w01a.

Failed to load data for block entity minecraft:dropper
com.google.gson.JsonSyntaxException: com.google.gson.stream.MalformedJsonException: Use JsonReader.setLenient(true) to accept malformed JSON at line 1 column 1 path $
	at com.google.gson.internal.Streams.parse(Streams.java:60)
	at com.google.gson.internal.bind.TreeTypeAdapter.read(TreeTypeAdapter.java:65)
	at vf.a(SourceFile:493)
	at vf.a(SourceFile:518)
	at hn$a.a(SourceFile:241)
	at bap.b(SourceFile:90)
	at baj.a(SourceFile:118)
	at bdm.a(SourceFile:367)
	at bdm.a(SourceFile:78)
	at rm.b(SourceFile:85)
	at rm.c(SourceFile:104)
	at net.minecraft.server.MinecraftServer.i_(SourceFile:375)
	at cmd.a(SourceFile:112)
	at cmd.d(SourceFile:128)
	at net.minecraft.server.MinecraftServer.run(SourceFile:479)
	at java.lang.Thread.run(Thread.java:745)
Caused by: com.google.gson.stream.MalformedJsonException: Use JsonReader.setLenient(true) to accept malformed JSON at line 1 column 1 path $
	at com.google.gson.stream.JsonReader.syntaxError(JsonReader.java:1559)
	at com.google.gson.stream.JsonReader.checkLenient(JsonReader.java:1401)
	at com.google.gson.stream.JsonReader.doPeek(JsonReader.java:593)
	at com.google.gson.stream.JsonReader.peek(JsonReader.java:425)
	at com.google.gson.internal.Streams.parse(Streams.java:46)
	... 15 more

Comments 1

md_5 2018-01-10T10:28:46Z

Issue is quite simple.

Currently the converter has a hardcoded list of tiles to convert:

minecraft:shulker_box
minecraft:dispenser
minecraft:banner
minecraft:chest
minecraft:brewing_stand
minecraft:enchanting_table
minecraft:furnace
minecraft:hopper

It is missing at least three entries from here:

Affecting 1.12.2 -> 18w01a conversions

minecraft:dropper
minecraft:command_block

Affecting 17w47a+ -> 18w01a conversions

minecraft:trapped_chest

Also have a sneaking suspicion that snapshot->18w01a Minecart command blocks may not be converted properly, but haven't checked.