Scaladoc regression in 2.13.4 related to relative entity link

[BalmungSan]

Reproduction steps

Using Scala 2.13.4 having the following in a file called test.scala

object foo {
  trait Bar {
    /** Returns a new [[Bar]]. */
    def f: Bar = ???
  }
}

trait Baz extends foo.Bar

Then running scaladoc test.scala produces the following warning:

test.scala:3: warning: Could not find any member to link for "Bar".
/** Returns a new [[Bar]] by applying a function. */
^

Problem

I would expect it to properly handle the relative entity link to Bar without producing any warnings; as it does when using 2.13.3, 2.12.13, 2.12.12, 2.11.12
Also, note that everything in that snippet is required to reproduce the error. If you remove the additional trait Baz or you remove the enclosing object foo then it works.

[SethTisue]

A likely next step here would be to bisect it to determine the PR responsible for the regression. That's almost always more efficient than trying to debug it from scratch.

[dwijnand]

Looks like scala/scala#9060 is responsible.