The bug
The fur patterns on horses are outlined by the glowing effect. The expected behavior is that only the outer edge of the horse should be outlined. This bug existed previously as MC-124109, which was fixed in 21w10a, but it was reintroduced in 21w11a.
To reproduce
/summon horse ~ ~ ~ {Variant:773,NoAI:1b,Glowing:1b}
Linked issues
Attachments
Comments


If the horse is simultaneously glowing and invisible, then the outline renders correctly. This is probably a side-effect of MC-218972.
[media]

Duplicate of [MC-124109]
@unknown, this ticket actually clones MC-124109, as this report was believed to be fixed in 21w10a.

I suggested reopening MC-124109 and resolving this as a duplicate but okay.
This ticket already has an assigned, "Mojang Priority" and "Assignee", so the likelihood of this being resolved as a duplicate is very low.

If a report is falsely resolved as fixed when it is not actually fixed, then the report is reopened. If a bug is fixed, but later comes back in a different version, then a new report is created and the new report is marked as a clone. In the case of this bug, the bug was fixed in 21w10a, but it came back in 21w11a. (The bug was not just believed to be fixed; it was fixed.)
Can confirm in 21w13a.
Can confirm in 21w14a.
Can confirm in 21w15a.
Can confirm in 21w16a.
Can confirm in 21w17a.

Can someone reopen MC-124109 and resolve this as a duplicate?

Appears fixed
Possibly due to resolution of MC-223602
The reintroduction of this bug was probably caused by the fix of MC-218765.