=head2 C<< rewrite_html >>

Rewrites all HTML links to be relative to the given URL. This
only rewrites things that look like C<< src= >> and C<< href= >> attributes.
Unquoted attributes will not be rewritten. This should be fixed.

=cut

sub rewrite_html {
    my($url, $html)= @_;
    $url = URI::URL->new( $url );
    
    #croak "Can only rewrite relative to an absolute URL!"
    #    unless $url->is_absolute;

    # Rewrite relative to absolute
    rewrite_html_inplace( $url, $html );
    
    $html
}

sub rewrite_html_inplace {
    my $url = shift;
    $url = URI::URL->new( $url );
    
    #croak "Can only rewrite relative to an absolute URL!"
    #    unless $url->is_absolute;

    # Rewrite relative to absolute
    $_[0] =~ s!((?:src|href)\s*=\s*(["']))(.+?)\2!$1 . relative_url(URI::URL->new( $url ),"$3") . $2!ge;
}