The Atom Text Editor is not part of PureOS (nor Debian) so it would be most helpful if you could try locate some other tool that is supported by PureOS which has same distortions, so that we can replicate within the constraints of the system.

Also, it is helpful if you can elaborate on the kind of distortions you are experiencing.
(yes, I know you included a screenshot, but it would be sad to spend countless hours making the "f" look more sharp if it was not that kind of distortion you really meant to raise as an issue here)

I have not found any other application with this same issue in PureOS, which is why I created a bug report for the Atom text editor specifically. I thought it appropriate to put the bug here, because it only happens in PureOS (not in Debian Stretch, Debian Testing, Linux Mint, or Trisquel 7/8), so I think it must be specific to something unique to PureOS.

I don't think that the distortions are necessarily tied to a specific character/font; they just seem to appear at random, once I've typed a couple characters or more. That's part of what makes it annoying; if it were just one specific character, it would be a lot easier to ignore and diagnose. Plus, like in the screen shot, you can also see that it applies not only to typed text, but also to the menus and options.

Thanks for (vaguely) hinting at what to look for in the screenshot. That is helpful.

I understand your reasoning on why you suspect something in PureOS is causing this issue. I tend to agree (although I can imagine other explanations too only indirectly triggered by PureOS). That does not change, however, that involving non-PureOS parts makes it more difficult to work on this issue.

It would likely be helpful if you can you provide the full list of what has been installed on Debian and PureOS, respectively - both what is installed using official Debian/PureOS packages, and what has been installed outside of Debian/PureOS sources.

It's actually easy to identify which apps were installed, because I tested this issue with a default installation of all operating systems mentioned, the only extra package being installed was the Atom package itself (along with its dependencies).

With Pure OS, simply use the latest ISO, available from pureos.net. With Debian Stretch, download the Net Installer for version 9.3 from the website, and install with the GNOME desktop. With Debian Testing, use the Debian Buster Alpha 2 Net Installer, with the GNOME desktop.

You would then just need to get a list of all the default packages for each distribution, and compare them; that should get you the information you need (for Debian distros, this is readily available from https://www.debian.org/distrib/packages.

Thanks for your information.

It seems this issue will not progress until someone try replicate your custom environment and then - hopefully for the sake of this issue - can replicate the issue you experience.

To repeat: It would be helpful if *you* can provide such information, since you already have the custom environment with the particular behaviour.