Glitch in wallpaper during transition from greeter to gala during login to desktop with HiDPI

Question

I have a 4k/uhd display and have set gnome scaling factor to 2 for my username and also the lightdm user so that greeter login screen also is "hidpi" enabled. I have greeter background set to a default wallpaper and my user account (gala) wallpaper is solid colour.

Now when I login and the transition from greeter to gala there is a brief flash where the wallpaper is tiled 2x2 (4x) like a grid, it briefly flashes that before switching to solid background and loading desktop.

I was trying to look through the greeter and gala code but couldn't figure out where this issue might be occurring (or if it's a Xorg config issue)... any ideas?

Answer 1

The elementary team were kind enough to review and accept my patch which is now in trunk! It should be available in Loki's greeter release whenever it next gets an update I believe. Again, this just addresses the 2x2 glitch during the login transition with HiDPI mode and the two bug reports mentioned are likely still open issues. Those bugs are likely due to differing aspect ratios of the monitor versus the wallpaper along with differing from the gala wallpaper scaling type setting like "stretch" or "zoom" or "scaled".