Thumbnails of pictures and PDF files on desktop do not keep aspect ratio. If I open the desktop folder in the default gnome file manager, the icons aren't stretched. The problem is only with what is shown on the desktop. See screenshot. What would you suggest for solving this?
With Ubuntu 20.04.1, with the most recent gnome-shell update (gnome-shell-extension-desktop-icons 20.04.0-3~ubuntu20.04.1), the bug still exists.
A possible fix is, in /usr/share/gnome-shell/extensions/desktop-icons@csoriano/fileItem.js,
let containerWidth = (this._icon.allocation.x2 - this._icon.allocation.x1) * scaleFactor;
let containerWidth = (this._icon.allocation.x2 - this._icon.allocation.x1);,
then re-login/reboot the system.
Basically, the scaleFactor multiplier here is unnecessary. Tested on Ubuntu 20.04.1, with display scale 200%. Desktop thumbnails work fine after removing the scaleFactor multiplier as above.
You can also see the bug report here.
This is a bug
The fix is already available via updates, but it is not perfect. The aspect ratio is still wrong for images that have aspect ratio less than that of the container.