[xslt] bug in templates.c

["Vakoc, Mark" <Mark_Vakoc jdedwards com>]

The following change introduces a mem fault in
xsltAttrTemplateValueProcessNode

http://cvs.gnome.org/bonsai/cvsquery.cgi?treeid=default&branch=HEAD&branchty
pe=match&dir=&file=&filetype=match&who=veillard&whotype=match&sortby=Date&ho
urs=2&date=explicit&mindate=08%2F21%2F2002+15%3A29&maxdate=08%2F21%2F2002+15
%3A29&cvsroot=%2Fcvs%2Fgnome

It assumes the function parameter 'node' is always valid, but when called
from xsltAttrTemplateValueProcess this parameter is always NULL.

The simple attached path checks that node is valid before using it.  Not
regression tested bug it fixes my crash!

cheers.

templates.diff