This repository was archived by the owner on May 26, 2018. It is now read-only.

Description
Noticed this on 1.7.10. Method appears to be exactly the same on master branch.
Method: https://github.com/MinecraftForge/FML/blob/master/src/main/java/net/minecraftforge/fml/common/registry/EntityRegistry.java#L253
During the method, if while searching the spawns list it finds an already existing entry for the mob, it still adds a brand new entry to the list.
Checked to be sure by adding an entry for EntityDragon, printing the list, adding another entry for the EntityDragon and printing a second time.
Result:
EntitySpider_(4-4):100
EntityZombie_(4-4):100
EntitySkeleton_(4-4):100
EntitySlime_(4-4):100
EntityEnderman_(1-4):10
EntityWitch_(1-1):5
EntityDragon*(1-5):100
EntitySpider_(4-4):100
EntityZombie_(4-4):100
EntitySkeleton_(4-4):100
EntitySlime_(4-4):100
EntityEnderman_(1-4):10
EntityWitch_(1-1):5
EntityDragon_(2-10):5
EntityDragon_(2-10):5
As you can see, two entries for EntityDragon in the list.