Gosh yeah, I hate that. I've lost track of how many times I've lost gems accidentally crafting colored torches, or getting stuck with random campfires...
One time I had two maces, one with super good traits and the other a blank slate. I planned to turn the blank one into a flaming mace in a minute, but still keep a hold of the Demonic normal mace in case the flaming one wouldn't happen to come with such good damage output. (I was in way early game, didn't have the Goblin Tinkerer yet.)
Well... first I wanted to check recipes for stuff I'd just mined aaaaaannnnnd.... it turned one of my maces into a flaming mace. Guess which one it picked? Yeah, my Demonic.
Turned it into a negative-stat one too (think it was Annoying). So I had to just sigh and turn my other mace into a flaming mace, which was eh ok, but... I lost so much bonus damage.
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HOW TO DUPLICATE:
It seems to depend on whether or not you had the necessary material/crafting station proximity, to make one of the items. Start a new world, kill a slime or two and chop some wood. Talk to the Guide (using XBox One or XBox 360 controller), and select for crafting recipes. Bam, enjoy the torch you didn't ask for.
It might also factor in how near a compatible crafting recipe your cursor on the menu is when you first open it. If the first method didn't trigger, then scroll up to the top of the recipes until you have the torch recipe highlighted, exit, then re-ask the Guide about Crafting again. Now you'll get your darn torch. Or further down the line, your campfire, your flaming mace, your crafting benches...
This started right at the 1.4 update, at very least by version 1.4.0.4 (I didn't play right away on launch, so I can't say if it was in the earlier iterations or not). I reported it back then, guess it didn't get noticed. I hope it can be fixed soon; it's REALLY annoying to have to lean over and grab my mouse (which does NOT trigger this issue) every time I wanna check recipes.. or if I'm playing on the tv, I literally have to go across the room and bend/kneel over (not fun with disabling back problems) just to check a recipe.
My details:
Version: Steam
Both Single and Multiplayer
Windows 8.1
Terraria Version 1.4.1.2 (though the bug started far earlier, first noticed by me in 1.4.0.4 though it may have started sooner.)
Controller: XBox 360
Playing Settings: Classic, Expert Difficulty.