[XeTeX] Polyglossia and Sanskrit

[Yves Codet]

Hello.

I am extending "hyph-sa.tex" (Sanskrit hyphenation patterns) so as to  
incorporate Gujarati script. Testing the result with a file whose  
preamble is:

\documentclass[a4paper,12pt]{article}
\usepackage{polyglossia}
\usepackage{fontspec}
\setdefaultlanguage{sanskrit}
\setmainfont[Ligatures=Rare]{Gujarati MT}

I get the following message:

! Package polyglossia Error:
  The current font does not contain the devanagari script!
  Please define \devanagarifont or \sanskritfont with \newfontfamily.

See the polyglossia package documentation for explanation.
Type  H <return>  for immediate help.
  ...

l.2 \select at language {sanskrit}

?

I wonder if this behaviour of Polyglossia should not be changed.  
Actually Sanskrit has no proper script, or it has many. If Devanagari  
is often preferred nowadays if does not mean that it is *the*  
Sanskrit script. I would be interested to know what members of the  
list think.

Best wishes,

Yves