This patch unified the code-path we used to render on Linux on all desktop-environments (removing an X11+GNOME/Unity special-case, effectively). It is needed to avoid rendering window corners without glitches on those environments.
I did a pass over the remaining unfixed regressions:
- Bug 1764502 is a perf regression which we unfortunately haven't fixed (that's partially on me). However this is the codepath that we were already using on both Wayland (everywhere) and every other non-GNOME X environment. So it effectively surfaced a performance issue that a lot of users already had already.
- Bug 1769553 only applies to 32-bit non-supported ubuntu versions (it's probably a GTK bug that we can't really workaround). I'll just wontfix that.
- Bug 1781262 is xwayland only (and I think we should rather ship wayland rather than workaround xwayland-specific issues).
- Bug 1788205 wasn't clear if it's our bug either (we could never reproduce it and looked like a compositor bug since it affected gedit and other gtk apps as well), though it seems there are some new STR in the bug which could help reproduce, so I'll try those and try to see what's up.
- Bug 1805703 is not a regression of this work because it still breaks with
DECORATION=system. It was probably due to it being a cloned bug. I'll remove from the regression list.