If doMobSpawn is set to false, zombie pigmen shouldn't be able to spawn.
To reproduce:
Create a world
/gamerule doMobSpawn false
create few nether portals
wait.
MC-29339
Zombie pigmen still spawning near Nether Portal with doMobSpawn set to false
Resolved
Duplicate
0
Duplicate of MC-4973, please use the search function to see if your bug has already been submitted. Currently over 58% of tickets are being resolved as duplicate.