Steps to reproduce:
use Editpane (or view) buffersets.
Project p1 open in View v1
Project p2 open in View v2
File f1 from project p1 is open in v2 but not v1.
Look at ProjectViewer in v1. f1 is underlined even though v1 does not show it in its buffer set.
Perhaps it should be underlined only if f1 is in View.getBuffers()?