Transparent rendering after VTE's 0.64.0 update

[guihkx]

Describe the problem: Recently, the vte3 package (Virtual Terminal library) was updated on Arch Linux. That update introduced a bug in this theme where everything gets transparent on GNOME Terminal, like so:

This issue has been reported to the VTE folks about 6 months ago, but it was ruled out as a theme bug:

https://gitlab.gnome.org/GNOME/vte/-/issues/284

Steps to reproduce:

1. Update VTE to 0.64.0
2. Set the theme to Pop-dark
3. Open GNOME Terminal
4. Window contents are transparent

Distribution: Arch Linux

Pop version: 5.3.1.r3.g5ab6f1e4-1 (from this AUR package)

[jacobgkau]

In Pop!_OS, we don't set the terminal colors via the GTK theme; they're currently set via a gsettings override: https://github.com/pop-os/default-settings/blob/master_focal/debian/pop-default-settings.gsettings-override#L55

The background on Pop, for either the light or the dark theme, is #333333:

I see that in Arch, downgrading to VTE version 0.62.3-1 gets a legible terminal back, but the background color is #272727 in the dark theme and #ffffff in the light theme:

That's just the base_color variable in gtk-theme, which GNOME Terminal previously used as a fallback. We can fix the transparency fairly easily by defining text_view_bg to be the same as base_color. It still won't be the Pop color scheme, but it will be legible again.

[jacobgkau]

Using the 6% darkening for the background color in the dark theme that Adwaita uses, contrast does seem a bit better:

GNOME Contrast confirms the ratio with the new scheme is greater than the old one (it's around 6.1 vs 7.2).

[guihkx]

Btw, I've tested the patch and now it works as expected:

Thank you very much ❤️