Re: music2xml script, musicexp.py, self.short_indent/char_per_cm, and a division by zero

Le 30/12/2022 à 15:09, James Wilkinson a écrit :
> Hello everyone,
>
> Firstly, thank you for all your work on Lilypond, and a very Happy New
> Year!
>
> I hope this is the right place to report bugs with musicxml2ly (version
> 2.23.82, from Fedora).
>
> In musicexp.py, in class Paper, def print_ly(self, printer), there is
> this snippet:
>
>          char_per_cm = (len(self.get_longest_instrument_name())
>                         * 13) / self.page_width
>          if self.indent != 0:
>              self.print_length_field(printer, "indent", self.indent/char_per_cm)
>          if self.short_indent != 0:
>              self.print_length_field(
>                  printer, "short-indent", self.short_indent/char_per_cm)
>
> It’s possible for there not to be a longest instrument name, char_per_cm
> to be zero, self.short_indent not to be zero, and the final division to
> raise a divide-by-zero error. A very minimal “fix” of
>          if self.short_indent != 0 and char_per_cm != 0:
> enabled me to run the conversion.
>
> The error message from the original version was this:
>
> $ musicxml2ly Good_Christian_Men.mxl
> musicxml2ly: Reading MusicXML from Good_Christian_Men.mxl ...
> musicxml2ly: Input file Good_Christian_Men.mxl is compressed, extracting raw MusicXML data
> musicxml2ly: Converting to LilyPond expressions...
> musicxml2ly: Converting to LilyPond expressions...
> musicxml2ly: Converting to LilyPond expressions...
> musicxml2ly: Converting to LilyPond expressions...
> musicxml2ly: Output to `Good_Christian_Men.ly'
> Traceback (most recent call last):
>    File "/usr/bin/musicxml2ly", line 3482, in <module>
>      main()
>    File "/usr/bin/musicxml2ly", line 3475, in main
>      voices = convert(filename, options)
>               ^^^^^^^^^^^^^^^^^^^^^^^^^^
>    File "/usr/bin/musicxml2ly", line 3372, in convert
>      paper_information.print_ly(printer)
>    File "/usr/share/lilypond/2.23.82/python/musicexp.py", line 1026, in print_ly
>      printer, "short-indent", self.short_indent/char_per_cm)
>                               ~~~~~~~~~~~~~~~~~^~~~~~~~~~~~
> ZeroDivisionError: float division by zero
>
> The file is available at
> https://www.cpdl.org/wiki/images/f/f9/Good_Christian_Men.mxl .
>
> Thanks for your time, and hope this helps,
>




Thanks, this is now https://gitlab.com/lilypond/lilypond/-/issues/6518

Since the fix looks quite simple, would you be willing to submit the 
corresponding patch yourself?

Best,
Jean