I just wanted to hold it across the release cut, it's headed to master shortly.

@epriestley what's blocking landing this diff?

Sounds good. It felt slightly odd to me at first, too, but I think I also got used to it.

It wasn't a major UI issue to start with and yes, you get used to it. I would ignore.

The empty space means "this is a normal commit with no special audit state", and the column collapses if no commits have issues (see this task for an example). That seems fairly reasonable to me?

The underlying code is still a bit shaky, so let me know if you catch other issues.

In DifferentialHunkParser->generateVisibleLinesMask(), we pass a 0-based array in and get a 1-based ("line number") array out. The loop condition stops us from reaching the last line of the 0-based array.

I don't currently plan to pursue this.

Layout looks very neat but a strange too with that big space gap between the icon on each row and the actual text in this case:

After D20877, we'll forcefully override this option when generating diffs internally.

One change we can make here is to explicitly specify -c diff.suppressBlankEmpty false in the arc diff command, as we currently use --src-prefix and --dst-prefix to override diff.mnemonicprefix. This is likely desirable, but it would be good to also parse these diffs properly if they arrive through --raw or copy/pasting, etc.