Re: "Programming error" message

[Patrick McCarty]

On 2010-02-28, Werner LEMBERG wrote:
> 
> > I neglected to mention that in recent 2.13 versions, the warning
> > messages for invalid character encoding look like this:
> >
> >   (process:1375): Pango-WARNING **: Invalid UTF-8 string passed to 
> > pango_layout_set_text()
> >
> > These warnings are generated by Pango.
> >
> > Is this an improvement?
> 
> Yes, thanks.  I assume that it is not possible to add the offending
> text string to the warning message since a Pango warning is not
> visible to lilypond...  Perhaps it makes sense to add a UTF-8 checker
> to lilypond just for that.

It would be very simple to check for invalid UTF-8, since we can use
GLib's g_utf_validate() function.  In fact, Pango uses this same
function in pango_layout_set_text().

Unfortunately, it would be much more complicated (I think) to output
the offending string, since we would have to convert an arbitrarily
encoded string to UTF-8, and then display it along with the
warning/error.

And this assumes we are dealing with a UTF-8 locale.

What if we output a message like this instead:

  warning: invalid UTF-8 string found at row 3, column 10


I think this would be easier to implement.

Thanks,
Patrick