Allowing some mobs to attack you while wearing something thorns enchanted doesn't make them take damage.
Comments 3
Is this still a concern in the current Minecraft version? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases. If this has been done, we can reopen the issue.
Keep in mind that the "Resolved"-Status on this ticket just means "Answered", and that we are waiting for further information on whether this issue still exists or not. We will reopen it as soon as the requested information has been delivered.
Perhaps intended. The Thorns enchantment only sometimes damages the mob, the higher the level the higher the success rate:
http://minecraft.gamepedia.com/Enchanting#Thorns
(I tested with wolves, golems and spiders)