Bukkit/CraftBukkit — pull request #988 by cexikitin (2013-01-13 19:59:12+00:00)
Title: Fix squids not spawning when spawn-limits.ambient is set to 0.

By using return 0, we exit the loop prematurely preventing other
creature types from being spawned if one type is set to 0. By using
continue we move on to the other types and allow them to spawn properly.