From Minecraft Wiki
September 2, 2015
15w36a is the nineteenth snapshot released for 1.9.
collisionRuleadded as a team rule to the scoreboard.
- It determines whether or not entities can push each other, and whether or not it's team dependent.
- Most entities can now be pushed by other entities.
- The exceptions being: items, paintings, ender crystals, areaEffectCloud, item frames and xp orbs.
- These can be overridden for mobs and players through a team rule.
- The same class of entities are now "magnetic" to the fishing rod bobber, and in the case of mobs/players will no longer suffer from knockback or pseudo-damage.
- Armor protection calculations have been nerfed:
- Sharpness and Protection enchantments have been nerfed.
- Can no longer be placed by players who are unable to use commands.
- All mobs
- No longer reset their AI when hit.
- Due to MC-87946, all hostile mobs can now draw line of sight through solid blocks in order to track the player.
- Detection range for players wearing their corresponding mob head adjusted to be 50% of the normal range again.
- Optimized memory usage when connected to servers.
- 7 issues fixed
- From released versions before 1.9
- MC-7980 – Enderman teleportation and behavior irregular.
- MC-59098 – Enderman only make the 'stare' noise as long as the player is close to the Enderman.
- MC-64591 – Wither Skeletons wield sword incorrectly.
- From the 1.9 development versions
- MC-82955 – Left hand items render incorrectly on Alex model skins.
- MC-86840 – Armor durability affecting protection is not working right.
- MC-87611 – Chains of conditional Command Blocks don't work properly.
- From the previous development version
- MC-87759 – Hopper:
java.lang.NullPointerException: Loading entity NBT.