Arrow has water potion when summoned or updated

Confirmed for 17w06a.

Confirmed for 17w17a.

Confirmed for Minecraft 1.12 Pre-Release 4

It's 1.12-pre4 now actually.

Confirmed for 1.12-pre6.

in 1.12

Thanks! Just FYI, you may find code easier to understand if you use MCP instead of NMS, as MCP names the majority of methods.

Confirmed!

It's already set to confirmed.

Confirmed for 49a, 49b, 50a

Confirmed as recently as 18w01a. And I know why, too. The code that clears the potion effect for non-potion arrows is the setPotionEffect method of EntityTippedArrow. This is called whenever an arrow entity is created via the ItemArrow's createArrow() method, as well as when skeletons or dispensers fire an arrow. However, it is not called when the EntityTippedArrow is summoned on its own.

I would suggest that setPotionEffect() be called when an arrow is summoned, and the getArrowStack() method made public. Then it would be as simple as having CommandSummon check if the entity is an instanceof EntityTippedArrow and, if so, call entity.setPotionEffect(entity.getArrowStack()) (similarly to how the summon command currently checks if the entity is an instanceof EntityLiving and calls its onInitialSpawn method if so).

I found setting the color to -1 works

I got this bug from the code;
execute as @e[type=snowball] facing entity Flexie_ eyes run summon arrow ~ ~ ~ {Motion:[0.0,0.0,2.5],Time:1}
On 1.13.2