should COMPRESSION_NONE be 3?

[17183248569]

in your code it is 0.
i m not sure but i think that it should be 3.

[MestreLion]

This is possibly related to issue #4 : up until then there was no COMPRESSION_NONE (either 3 or 0). This is a constant I made up just to have a "falsy" value for compression in a blank object . But MCA "specs" mention only two possible values, 1 for Gzip and 2 for Zlib, and in practice Minecraft only used Zlib in all it's chunks since then.

This possibly changed with the introduction of the so called "external chunks". Perhaps 0 (or 3) is now used to indicate the chunks data is in an external file.

McWorldLib was not yet updated to support this new feature

[MestreLion]

External MCC chunks are not yet supported, but I changed the COMPRESSION_* "enum" handling to properly reflect the WIki. Now COMPRESSION_NONE is 3 and it's not an invalid value. The invalid value of 0 is now unnamed, and RegionChunk's constructor by default uses 2 (COMPRESSION_ZLIB) instead of the invalid 0, as it's the only compression used by Minecraft client