I had a full inventory, with lots of gems. I did /cnd all, and they turned into leather boots and came out of my inventory. I got all the gems from hunting shipwrecks.
A bunch of various mob drops, mostly leather/foods/feathers and random clutter gem wise I'm guessing, but: 12 Emeralds 20 Diamonds 20 Lapis 80 Iron Ingots 70 Gold Ingots 100 Coal
I put all the above items as one stack in my inventory, and did /cnd all Result is correct: I'll need more steps to reproduce properly.
they dropped on the floor and turned into leather boots, which I didn't have did you have a full inventory? every spot was taken, and then I /cnd'd and instead of the blocks turning into blocks, they turned into leather boots.
I'm sorry but everything I try, I cannot get this to reproduce. If you ever come up with reproduction steps let me know. I have even attempted to overflow my inventory with leather, diamond, coal, etc. They correctly dropped.
I'll have @Supergigant_Ring look into this and make leather not part of /condense, or better yet examine the entire /condense command and see if it possibly needs updating in regards to 1.13.x
