System Information
Operating system: Windows-10-10.0.17134 64 Bits
Graphics card: GeForce GTX 850M/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 419.67

Blender Version
Broken: version: 2.80 (sub 54), branch: blender2.7, commit date: 2019-04-07 15:02, hash: rB75f551facaf0
Worked: (optional)

Short description of error
in 2.8 the stroke of fill grediant looks wierd that it works but not represent what I'm working on.

in 2.8

in 2.79
note: after some experiaments I found it only works off when I add the image editor window to the workspace... apart from that it works correctly!
Exact steps for others to reproduce the error
open blender 2.8
click on texture paint workspace..
click fill tool
click on grediant option
try to add grediant
the problem apears