V2.8 - Mesh error in weight painting; spikes to infinity - Seen before 2.79

After going back to object mode from weight painting on a rigged model often parts of the mesh extend to infinity. Checking weights turns out to be normal, at least visibly, and every few transitions or viewport angle changes the spikes appear on different parts of the mesh.

I have seen something similar back in 2.6x with organic models when using multires modifier, but in this case no modifiers were added. I am uneasy about reporting this as a bug because it is so obvious that either everyone knows about it already or I’m doing something wrong.

http://pasteall.org/pic/c93787278fd8c4df3388b818d726ab34
http://pasteall.org/pic/47f7c1174d1fc2e5e4fd7f39fb6d0790