Comment 12 for bug 1647292

Yes it's a different branch making CSS styling more flexible generally, and attempting to fix a number of transparency issues. Unfortunately the fixes seem to be very theme dependent. i.e. by fixing Ambient tab header background, Adwaita tab backgrounds become transparent. I think this is because they are defining colours with different names.

The current fix for *this* bug is just a two line addition though. I can push it up to gtk3 no problem, but the question mark is whether or not it should keep the ability to revert to the old Adwaita behaviour when sizing is set to -1. If we are going to completely eliminate the Adwaita behaviour then the fix needs to be in a slightly different place in the code.

As far as I can tell gtk2 does not have the same issue, and I'm not going to be doing much at all from now on with the gtk2 branch, focusing instead on gtk3. Certainly no major changes are going to go into gtk2 (as an example, someone is working on iTerm2 style tmux integration, which will only go into gtk3.)