Should remain backwards compatible with 1.13. Removed blocks/items will
be forwarded to the "replacement" block/item. (e.g. BlockTypes.SIGN will
find OAK_SIGN on 1.14.)
The new command now writes a json file to WorldEdit's working directory with instructions on which chunks to delete, which is read by the plugin/mod at startup and calls the ChunkDeleter.
The chunk deleter parses the json and iterates the instructions, backing up .mca files as it goes and overwriting the offset headers with 0 wherever a chunk needs to be deleted.
This allows Minecraft to reclaim the space used for that chunk, as well as forcing it to be generated from scratch next time the area is loaded.
New to 1.14, Mojang stores .mca files which don't contain chunks in the
poi folder.
Note: we explicitly filter *out* the poi folder, instead of filtering
*to* the regions folder, since old versions of minecraft had regions
directly in the world folder (instead of a regions subfolder).
They now additionally take a direction in which the simulated item usage
should be facing.
Also allow the item parser to parse "hand" and "offhand" as items, to
allow platforms with NBT item support return items with NBT (since
parsing is a slightly more complex task).
Legacy mapper now uses the data fixers to upgrade blocks and item types
(e.g. signs, dyes that changed names in 1.14).
The sponge schematic reader can now attempt to use the data fixers to
upgrade blocks, block entities, biomes and entities. This has been
tested with the 1.13 -> 1.14 changes. It is yet to be seen if it will
continue to work because...
The mc edit schematic reader has code for using data fixers, but it is
currently disabled as there seem to be some issues with fixing up older
block entities.