[bug?] lily chokes on unavailable unicode char

[Juergen Reuter]

Hi,

lyrics with non-latin characters, such as in input/sakura-sakura.ly, 
basically compile fine on my machine without any error message, and the 
output looks fine.

If, however, I replace one of the non-latin characters with an obviously 
unavailable utf-8 code (at least with the fonts currently installed on my 
machine) such as the character with the code (hexadecimal) 211F or 2123, 
lily spits out the following messages:

warning: no PostScript font name for font 
`/usr/share/fonts/bitmap-fonts/10x20.pcf'
warning: FreeType face has no PostScript font name
programming error: Improbable offset for stencil: -inf staff space
Setting to zero.
continuing, cross fingers

That is, lily does not even consider that a unicode character may not be 
available?

By the way, do you know of any freely available fonts that include 
characters 211F and 2123?  It would be nice to have them for Gregorian 
chant notation.

Greetings,
Juergen