Issue 1939 in lilypond: showLastLength with hidden tie error message

[lilypond]

Status: Accepted
Owner: ----
Labels: Type-Defect Regression

New issue 1939 by address@hidden: showLastLength with hidden tie  
error message
http://code.google.com/p/lilypond/issues/detail?id=1939

Reported by Nick Payne and Reinhold Kainhofer:
Nick: I'm setting Bach's BWV853 (Prelude from WTC 1), using showLastLength  
to
just engrave the last six bars added, and as I add bars I'm getting
warnings about unterminated ties that come and go as the bars are added.
The reason I say the warning is bogus is because there are no ties
across barlines anywhere in the piece, and when I have a look at the
bar(s) being complained of, there are no ties anywhere near.

Reinhold:
Attached is a minimal example of this bug. It seems that with  
showLastLength,
a tie in the hidden parts will be carried over to the first displayed note!

Cheers,
Reinhold

PS: The console output of the example is:

address@hidden:~/lilypond/lilypond$ LANGUAGE=C lilypond showlastlength-
tie.ly
GNU LilyPond 2.15.13
Processing `showlastlength-tie.ly'
Parsing...
Interpreting music...
showlastlength-tie.ly:8:2: warning: unterminated tie

  b2 c
Preprocessing graphical objects...
Finding the ideal number of pages...
Fitting music on 1 page...
Drawing systems...
Layout output to `showlastlength-tie.ps'...
Converting to `./showlastlength-tie.pdf'...
Success: compilation successfully completed

8<-----------------8<--------------
showlastlength-tie.ly

\version "2.15.12"

showLastLength = R1

\relative c'' {
  % This tie will be applied to the next measure, despite being hidden by  
showLastLength!
  e2~ e |
  b2 c
}

Colin:
2.12.3 and 2.13.63 do not show the error, 2.15.11 and .13 do show it.