Bukkit/CraftBukkit — pull request #1166 by RingOfStorms (2013-06-04 06:57:51+00:00)
Title: Strict and more accurate recipe lookup

The getRecipesFor (item) before would return results that were not necessarily true. With the old system it only checked the item type, and not the amount. This being said, if you were to input 9 gold ingots, one of the recipes would be 9 gold nuggets. which is not true as 9 gold nuggets can only make 1 ingot.

This is a problem for a plugin that looks at the recipe's and goes from lets say 1 ingot -> 9 nuggets. Using this system, the nuggets can go to 9 nuggets -> 9 ingots. Which is obviously not good, and is a mean of duping items.