I was curious if I'd broken something, since it sounds like something I woulda broke.

This may be old-fashioned, but it would nice to have a test to show before and after.

In the crossword, TIL "status quo" is actually https://en.wikipedia.org/wiki/Status_quo_ante_bellum

That is, "status quo" means you're rewinding not just past the last commit, but past the last war.

I understand the change to mean you must compare both start and len because of prefixes. I feel like I just commented about prefixes, but I don't remember if that was at my day job or my happy place. Is that a hazard of FOSS?

I don't think the potential bug could be reproduced in partest in a straightforward manner.

object C {
  def foo = 1
  def fo = 2
}

class Test {
  import C.foo
  fo
}

If something in the compiler (or a macro) had called TermName("foo").subName, 0, 2) prior to parsing that file, this might incorrectly typecheck.