+if ($usage) {
+ # first() does not work inside given >:(
+ while (my ($browser, $row) = each %$canihas) {
+ my $verlist = $versions{$browser} or next;
+ my %supported = map { $_ => 1 } @$verlist;
+ $row->{$_} //= undef for @$verlist; # ensure stable keys during iteration
+ while (my ($version, $usage) = each %$row) {
+ next if defined $supported{$version};
+ my $next = first { paddedver($_) ge paddedver($version) } @$verlist
+ or warn("No fallback found for $browser v$version; $usage% ignored"), next;
+ $row->{$next} += $usage;
+ $row->{$version} = 0; # balance browser total
+ }
+ }
+}