Bar number too close to volta bracket

[Dan Eble]

\version "2.20.0"
{
  \set Score.barNumberVisibility = #(every-nth-bar-number-visible 2)
  \override Score.BarNumber.break-visibility = #end-of-line-invisible
  \repeat volta 2 R1 \alternative { R1 R1 }
}

With master, the bar number is placed up against the volta bracket.  With 
2.20.0, the bracket is moved up to avoid it.  (I'm not fond of either result.)  
I don't know whether this is a bug, but it seemed noteworthy.
— 
Dan