System Information
Operating system: Linux-4.15.0-50-generic-x86_64-with-debian-stretch-sid 64 Bits
Graphics card: GeForce GTX 760/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 384.130

Blender Version
Broken: version: 2.80 (sub 71), branch: blender2.7, commit date: 2019-05-21 22:53, hash: rB8accb5a46f4a

Short description of error
information from texture paint is lost if the color space of the image is changed in the image texture node

Exact steps for others to reproduce the error
from the default template, go to the "Texture Painting" workspace
add a new base color slot and do some painting
switch to the "Shading" workspace
in the image texture node, change the color space to sRGB to linear
the painting information is lost
this information can't be recovered by changing back the color space to sRGB
the same occurs if you change the color space to baked images