I was playing SinglePlayer Snapshot. When I went to repair two picks in my crating table to save inventory space it let me get the newer pick, but let me keep the older ones. SO this leads to unlimited picks. It works for all tools/armor as far as im aware.
Environment
Put your operating system (Windows 7, Windows XP, OSX) and Java version if you know it here
Duplicate of MC-46715 - If you have not, please use the search function in the future, to see if your bug has already been submitted. If you could not find the original report, please comment with the keywords you searched for.