ly2dvi exit status

[Karl Berry]

It seems ly2dvi does not propagate the exit status from lilypond.  This
is annoying in Makefiles, etc.

Lilypond 1.6.0, red hat linux 7.3.

Thanks,
k


$ echo junk >test.ly
$ (ly2dvi -P test.ly; echo exited $?)

Running LilyPond...
GNU LilyPond 1.6.0
Now processing: `test.ly'
Parsing...
error: parse error, unexpected $, expecting '='


/u/karl/tex/lily/test.ly:1:4: warning: Braces don't match:
junk
    
error: 
LilyPond failed on the input file (exit status 1).

Traceback (innermost last):
  File "/usr/local/gnu/bin/ly2dvi", line 1000, in ?
    run_lilypond (files, dep_prefix)
  File "/usr/local/gnu/bin/ly2dvi", line 512, in run_lilypond
    error ( "\n" \
  File "/usr/local/gnu/bin/ly2dvi", line 144, in error
    raise _ ("Exiting ... ")
Exiting ... 
exited 0