my $xoids = xoids_for($self, $eml) // return;
$docids //= [];
@$docids = sort { $a <=> $b } values %$xoids;
- my @cur_kw = msg_keywords($self, $docids->[0]);
- join("\0", @$new_kw_sorted) eq join("\0", @cur_kw) ? 0 : 1;
+ my $cur_kw = msg_keywords($self, $docids->[0]);
+
+ # RFC 5550 sec 5.9 on the $Forwarded keyword states:
+ # "Once set, the flag SHOULD NOT be cleared"
+ if (exists($cur_kw->{forwarded}) &&
+ !grep(/\Aforwarded\z/, @$new_kw_sorted)) {
+ delete $cur_kw->{forwarded};
+ }
+ $cur_kw = join("\0", sort keys %$cur_kw);
+ join("\0", @$new_kw_sorted) eq $cur_kw ? 0 : 1;
}
sub all_terms {