cueClef in cueVoice changes clef of outer voice context

[Herbert Mraz via bug-lilypond]

Hi,
 
when writing a passage with a cue voice using a different clef, the clef won't 
change back to the main voice's context.
Back in the main context, the clef even cannot be changed back by explicitly 
setting the clef, but only by setting the cueClef.
 
Here is an example
%%%% BEGIN EXAMPLE
\version "2.25.25"
\new Voice = "outer" \relative c'' {
  \clef violin
  c1
  <<
    \new CueVoice = "altocue" {
      \voiceOne
      \cueClef alto
      c
    }
    \context Voice = "outer" {
      \voiceTwo
      R1
    }
  >> \oneVoice
  % Shouldn't there "outer" Voice context continue
  % and and implicit violin clef being printed?
  c
  % even an explicit clef change has no effect:
  \clef violin
  c
  % only cueClef resets the clef setting properly
  \cueClef violin
  c    
}
 
%%%% END EXAMPLE
 
Regards,
Herbert