Summoned/Dispensed arrows don't reflect Fireballs
So this is a weird one.
Steps to reproduce:
1. Place a repreating Command Block
2. Input command: /execute @e[type=Arrow] ~ ~ ~
/summon Fireball ~ ~ ~ {direction:[0.0,0.0,0.0]
3. Power the Command block
4. Place a dispenser
5. Put arrow in the dispenser
6. Power the Dispenser.
Observe that arrow DOES hit the Fireball, since hit sound can be heard, and the arrow disappears.
Same goes with arrows summoned by commands/command blocks.
Follow steps 1-3.
4. Input into the chat /summon Arrow ~ ~ ~
The hit sound can be heard again, the arrow disappears too upon hitting the spawned Fireball.
Environment
Windows 7 Home Premium 64Bit / Windows 10 Pro 64Bit / Ubuntu 16.04 LTS x64
Java 8 51 (64bit) / Java 8 101 (64bit)
Linked Issues
Created Issue:
Summoned/Dispensed arrows don't reflect Fireballs
So this is a weird one.
Steps to reproduce:
{direction:[0.0,0.0,0.0]}
1. Place a repreating Command Block
2. Input command: /execute @e[type=Arrow] ~ ~ ~ /summon Fireball ~ ~ ~3. Power the Command block
4. Place a dispenser
5. Put arrow in the dispenser
6. Power the Dispenser.
Observe that arrow DOES hit the Fireball, since hit sound can be heard, and the arrow disappears.Environment
Windows 7 Home Premium 64Bit
Java 8 51 (64bit)
So this is a weird one.
Steps to reproduce:
{direction:[0.0,0.0,0.0]}
1. Place a repreating Command Block
2. Input command: /execute @e[type=Arrow] ~ ~ ~ /summon Fireball ~ ~ ~3. Power the Command block
4. Place a dispenser
5. Put arrow in the dispenser
6. Power the Dispenser.
Observe that arrow DOES hit the Fireball, since hit sound can be heard, and the arrow disappears.Same goes with arrows summoned by commands/command blocks.
Follow steps 1-3.
4. Input into the chat /summon Arrow ~ ~ ~ {motion
So this is a weird one.
Steps to reproduce:
{direction:[0.0,0.0,0.0]}
1. Place a repreating Command Block
2. Input command: /execute @e[type=Arrow] ~ ~ ~ /summon Fireball ~ ~ ~3. Power the Command block
4. Place a dispenser
5. Put arrow in the dispenser
6. Power the Dispenser.
Observe that arrow DOES hit the Fireball, since hit sound can be heard, and the arrow disappears.Same goes with arrows summoned by commands/command blocks.
Follow steps 1-3.
4. Input into the chat /summon Arrow ~ ~ ~{motionSo this is a weird one.
Steps to reproduce:
{direction:[0.0,0.0,0.0]}
1. Place a repreating Command Block
2. Input command: /execute @e[type=Arrow] ~ ~ ~ /summon Fireball ~ ~ ~3. Power the Command block
4. Place a dispenser
5. Put arrow in the dispenser
6. Power the Dispenser.
Observe that arrow DOES hit the Fireball, since hit sound can be heard, and the arrow disappears.Same goes with arrows summoned by commands/command blocks.
{Motion:[5.0,0.0,0.0]}
Follow steps 1-3.
4. Input into the chat /summon Arrow ~ ~ ~The hit sound can be heard again, the arrow disappears too.
So this is a weird one.
Steps to reproduce:
{direction:[0.0,0.0,0.0]}
1. Place a repreating Command Block
2. Input command: /execute @e[type=Arrow] ~ ~ ~ /summon Fireball ~ ~ ~3. Power the Command block
4. Place a dispenser
5. Put arrow in the dispenser
6. Power the Dispenser.
Observe that arrow DOES hit the Fireball, since hit sound can be heard, and the arrow disappears.Same goes with arrows summoned by commands/command blocks.
{Motion:[5.0,0.0,0.0]}
Follow steps 1-3.
4. Input into the chat /summon Arrow ~ ~ ~The hit sound can be heard again, the arrow disappears too upon hitting the spawned Fireball.
relates to
After further experimenting I've come up with conclusion, that when a fireball is hit by an arrow, takes its new direction from direction the player is shooting at. I've delayed summoning of fireball by few seconds, and shot straight upwards. When the arrow started falling, the fireball spawned, and it went... straight upwards. Despite being hit from above.
So this is a weird one.
Steps to reproduce:
{direction:[0.0,0.0,0.0]}
1. Place a repreating Command Block
2. Input command: /execute @e[type=Arrow]~ ~ ~/summon Fireball ~ ~ ~3. Power the Command block
4. Place a dispenser
5. Put arrow in the dispenser
6. Power the Dispenser.
Observe that arrow DOES hit the Fireball, since hit sound can be heard, and the arrow disappears.Same goes with arrows summoned by commands/command blocks.
{Motion:[5.0,0.0,0.0]}
Follow steps 1-3.
4. Input into the chat /summon Arrow ~ ~ ~The hit sound can be heard again, the arrow disappears too upon hitting the spawned Fireball.
So this is a weird one.
Steps to reproduce:
{direction:[0.0,0.0,0.0]}
1. Place a repreating Command Block
2. Input command: /execute @e[type=Arrow] ~ ~ ~
code/summon Fireball ~ ~ ~code
3. Power the Command block
4. Place a dispenser
5. Put arrow in the dispenser
6. Power the Dispenser.
Observe that arrow DOES hit the Fireball, since hit sound can be heard, and the arrow disappears.Same goes with arrows summoned by commands/command blocks.
{Motion:[5.0,0.0,0.0]}
Follow steps 1-3.
4. Input into the chat /summon Arrow ~ ~ ~The hit sound can be heard again, the arrow disappears too upon hitting the spawned Fireball.
So this is a weird one.
Steps to reproduce:
{direction:[0.0,0.0,0.0]}
1. Place a repreating Command Block
2. Input command: /execute @e[type=Arrow] ~ ~ ~
code/summon Fireball ~ ~ ~
code
3. Power the Command block
4. Place a dispenser
5. Put arrow in the dispenser
6. Power the Dispenser.
Observe that arrow DOES hit the Fireball, since hit sound can be heard, and the arrow disappears.Same goes with arrows summoned by commands/command blocks.
{Motion:[5.0,0.0,0.0]}
Follow steps 1-3.
4. Input into the chat /summon Arrow ~ ~ ~The hit sound can be heard again, the arrow disappears too upon hitting the spawned Fireball.
So this is a weird one.
Steps to reproduce:
1. Place a repreating Command Block
2. Input command: /execute @e[type=Arrow] ~ ~ ~
/summon Fireball ~ ~ ~ {direction:[0.0,0.0,0.0]
3. Power the Command block
4. Place a dispenser
5. Put arrow in the dispenser
6. Power the Dispenser.
Observe that arrow DOES hit the Fireball, since hit sound can be heard, and the arrow disappears.Same goes with arrows summoned by commands/command blocks.
{Motion:[5.0,0.0,0.0]}
Follow steps 1-3.
4. Input into the chat /summon Arrow ~ ~ ~The hit sound can be heard again, the arrow disappears too upon hitting the spawned Fireball.

Is this still an issue in the most recent versions (currently that is 1.10.2, or 16w42a) of Minecraft? If so, please update the affected versions and help us keeping this ticket updated from time to time.
Yes, I'm sorry, I've completely forgotten about the issue. I've added versions it affects.
Previous comment has been deleted as the behaviour is EVEN STRANGER than that. When I added a "direction" tag to summon command it didn't affect anything. I tried shooting the arrows with the delay again and I've found out, that the fireball is taking THE DIRECTION PLAYER IS LOOKING AT when hit. I'll try to attach an appropriate video soon.
I've uploaded it to Youtube to preserve quality of video. https://youtu.be/mteYszrAkhU
My guess is, when hitting the fireball with an arrow, the arrow triggers the same event as if the fireball was hit by melee attack. It would theoretically explain the issue, because when an arrow is summoned, it doesn't have any "owner", so the direction would be nullified. And dispensers... I think they are not valid owners, or they just summon an arrow without any additional tags.
Attached a Test world for testing the fireball behaviour. Repeating command block checks for any existing arrow and outputs to comparator redstone signal, to delay summoning of the fireball. Just shoot an arrow up in the air and look somewhere else.
Can't reproduce in 20w07a.