grindstone duplicates items both disenchanted and enchanted.

so i casually went over to a grindstone and tried to disenchant a lousy bow i got from fishing. i disenchanted it- normally it would give me only one copy of the disenchanted version, but it gave me two copies, one enchanted and one unenchanted. i tried it again and it did the same thing. so i spam clicked it. i was at level 9, with no additional XP, before doing this, and after about 20 seconds, i clicked out of the grindstone and found that there were enough copies of the bow- plus the original, which was still enchanted- to fill two full inventories, and my XP bar was halfway through LEVEL 31. i tested this with a few other items- helmet, pickaxe, trident- and they all went through the same issues. i was able to make an insanely good XP farm out of this glitch, but it should still be removed because i think it qualifies as cheating.