cargo (original) (raw)

What does this PR try to resolve?

This is a followup to #14800. Like that PR, this is a small incremental change that does not pull its own weight. If this PR is accepted, the next PR will unlock large performance wins. I am not posting them together because the logic of why this PR is correct is subtle and deserves to be discussed and reviewed without unrelated code changes.

How should we test and review this PR?

All tests pass on all commits. This should be reviewed one commit at a time.

Additional information

I pushed one commit at a time, so that CI can confirm that the assert (in the first commit) is never hit.