Two bars at the start of a repeat

[Owen Le Blanc]

Somtimes I would like to have two bars at the start of a repeat,
especially where there is a line break.  In the sample below I get
only a plain double bar at the start of the repeat.  If I uncomment
the line '\bar ".|:"' I get only the bar for starting the repeat, and
if the previous bar is at the end of a line, for example uncommenting
the "\break" line, I get no bar at the end of the line and the "start
repeat" bar at the beginning of the next line.  Is there any way to
get what I want?
     Yours,
     -- Owen
Dr O V Le Blanc

\version "2.24.3"
song = { \key c \major \time 4/4 \relative c' {
 c4 d e f \bar "||"
% \break
 }
 \repeat volta 2 { \relative c' {
% \bar ".|:"
 f4 e d c
}}}

\score {
 \new Staff { \song }
}