warning for index entry with :

[Karl Berry]

Although I know we talked about this warning with : in index entries, it
is seeming pretty problematic to me now.  In texinfo.txi, for instance,
there are more than a dozen in the output customization chapter:

texinfo.txi:20691: warning: Index entry in @vindex with : produces invalid 
Info: $Texi2HTML::address@hidden, in customization}
texinfo.txi:20119: warning: Index entry in @vtable with : produces invalid 
Info: $Texi2HTML::THIS_SECTION
..

which is for Perl things, like
@vindex $Texi2HTML::address@hidden, in customization}

Ok, so we're going to get rid of all that chapter so it doesn't actually
matter for us, but I'm sure there are other Perl or C++ or other manuals
which use : in such cases, and there is no reasonable alternative.

Choices I can see:
1) forget about the warning -- simplest.
2) have a texinfo-level option to turn off the warning -- ok, but a
     language wart forever.
3) have a cmdline option to turn off the warning -- easier, but it's
     really an aspect of the document, not the invocation.
4) really fix the problem, and all the related problems, by devising some
   quoting mechanism for the special chars -- ideal, but just seems like
     too big a job to take on now, delaying the years-delayed release
     still further ...
5) ?

Wdyt?

Thanks,
k