URL: https://github.com/terraform-providers/terraform-provider-google-beta/pull/1116/files#diff-1ae139f5fb2f3b78fda661a248925628
Screenshot:

On version 19.9.8
Ouch, I suppose you're on Chrome because it works correctly on Firefox.
You can disable indented-code-wrapping until this issue gets solved
Yup, Chrome indeed. Thanks for the workaround!
Hey @danawillow, I'm at RGH 19.9.8 running stable Chrome 76 on Windows 10 1903, and I'm not able to see any glitches like that in either split or unified diffs.

Can you mention the exact steps you went through to end up at the situation, it helps a lot for me to debug this thing. And also can I know the exact version and channel of Chrome you are running this on...?
Thanks!
I think both of us are on macOS, it may be font-related
FWIW I'm on linux and am having the same experience. Disabling indented-code-wrapping also works for me.
Same problem here on a Mac. This started showing up about a week ago. (same workaround works)
May be helpful, based on https://github.com/sindresorhus/refined-github/pull/2436/files
macOS Mojave 10.14.6
Chrome 77.0.3865.75
Font Menlo
Doesn't work ✖

Windows 10 build 1903
Chrome 77.0.3865.75
Font Consolas
Works ✔

Arch Linux 5.2.14
Chromium 77.0.3865.75
Font Liberation Mono
Doesn't work ✖

@fregante
the code wrap can also done by adding .soft-wrap class to #discussion_bucket element
Not sure if this is helpful but I think text-indent has some problems with tabs.
For me the feature works in repositories using spaces instead of tabs.
I can also replicate this issue in a jsbin.
I also included an hack with replacing the tabs with spaces.
On Arch Linux 5.3.7 this looks like this for me
Chromium 78.0

Interestingly in Firefox it is just a bit to short :sweat_smile:
Firefox 71.0

Most helpful comment
Ouch, I suppose you're on Chrome because it works correctly on Firefox.
You can disable
indented-code-wrappinguntil this issue gets solved