When new chunks are created (flying through a new world), passive mobs are still spawned on new chunks if /gamerule doMobSpawning is set to false. This happens on default worlds but not in superflat worlds.
Steps to reproduce:
1. Create new world, creative, default settings
2. set /gamerule doMobSpawning false
3. type /kill @e[type=!Player] a few times to get rid of all entities
4. Fly in a straight direction
5. observe the entity counter in F3 and the passive mobs on the ground such as Cows, Sheep and Rabbits being spawned
Linked issues
Comments 2
It should stop all mobs from spawning and it does but in default worlds, passive mobs are spawned on newly generated chunks and this ignores the gamerule.
Doesn't "doMobSpawning" only prevent hostile mob spawning?