Greetings!
I'm playing my first "real" game (not hindered by my bad choices on world creation) on Version 1.21.7 after buying VS a few months ago. I'm in my game's first December and I stopped by two traders by my original spawn point just to remember what they had. I noticed one of them had tools hanging up and curiosity got the better of me when I noticed an axe had a black head on it. To my surprise, when I reflexively right clicked on the tool rack, the copper wrench in the rack went into my off-hand slot. My inventory was full otherwise. After throwing aside some trash loot, I also now have a copper chisel, an andesite knife, an obsidian axe and an obsidian shovel that was leaning against the wall. Is this supposed to happen? Is it because I picked them up instead of destroying something to get them? After a quick search, I saw other people say this was impossible or you'd get a penalty for this. I'm pretty darn sure I didn't use any mods to allow this.