avoid_returning_this false positive?

[jakemac53]

Describe the issue

On the latest dev (2.19.0-398.0.dev) we started seeing this lint trigger for the following code:

BuilderOptions overrideWith(BuilderOptions? other) {
  if (other == null) return this;
  return BuilderOptions(
      {}
        ..addAll(config)
        ..addAll(other.config),
      isRoot: other.isRoot);
}

This is not simply returning this just to have a "fluid interface" - it also might return a new instance. So I don't believe the lint is intended to trigger in this case?

To Reproduce

Check out the build repo (https://github.com/dart-lang/build) at this commit e4d6b8d8d5ed01752c6726e2dcc324a1d60d8d6d, on the latest dev sdk, and run analyzer in the build directory.

Expected behavior

I don't expect to see any lints.

Additional context
Add any other context about the problem here.

[lrhn]

Agree. The argument for not returning this is that you should use cascades instead of chaining. That only makes sense if the return this; is unconditional, otherwise chaining won't be the same as cascades anyway.