Printing bar numbers for partial measures

[Patrick Karl]

The Notation Reference states that:  Bar numbers are typeset by default at the 
start of every line except the first line.  And there is an official snippet 
which shows how to get the bar number printed even at the first line.  However, 
there is apparently an issue if the first measure on a line is a partial 
measure, as demonstrated by the following snippet:

\version "2.14.2"

A =   \relative b' {

   \repeat volta 2 {
        \set Score.barNumberVisibility = #all-bar-numbers-visible
        \bar ""         
        \partial 2 a4 b                 % 0
        \repeat unfold 15 {c4 d e f}    % 1-15
        c4 d                            % 16
   }

   \break

   \repeat volta 2 {
        a4 b                            % 16
        \repeat unfold 15 {c4 d e f}    % 17-31
        c4 d                            % 32
   }
}


\score {
        \new Staff { \A  }
        \layout { }
}

Here, the bar number is not printed on either the 1st line or on the line that 
contains the initial partial measure from the 2nd volta

Is there a way to get these two bar numbers printed?  And if not, shouldn't 
this be mentioned in the "Known issues and warnings" that follow that section 
of the NR?